YASKAWA AQ6370B User Manual

User’s
Manual

AQ6370B
Optical Spectrum Analyzer

IM 735302-01E

1st Edition

Product Registration

Thank you for purchasing YOKOGAWA products.

YOKOGAWA provides registered users with a variety of information and
services.
Please allow us to serve you best by completing the product registration
form accessible from our homepage.

http://www.yokogawa.com/tm/

PIM 103-02E

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IM 735302-01E

Foreword

Thank you for purchasing the AQ6370B Optical Spectrum Analyzer. This instrument
enables high speed measurement of the optical properties of LD and LED light sources,
optical amps, and other devices. To improve ease of use, it includes mouse-based user
operation and a brand-new zoom function.
This user’s manual describes the instrument’s functions, operating procedures, and
handling precautions, and provides other important information for use of the instrument.
For correct operation, please read this manual thoroughly before use. After reading this
manual, keep it in a convenient location for quick reference in the event a question arises
during operation. There are two manuals for the AQ6370B including this one. Read them
along with this manual.

Manual Title Manual No. Description

AQ6370B Optical Spectrum Analyzer IM 735302-01E This manual. Explains all functions
User’s Manual and operating procedures of the
(Vol 1/2) AQ6370B except remote control and

program functions.

AQ6370B/AQ6375 Optical Spectrum IM 735302-17E Explains functions for controlling the
Analyzer Remote Control instrument with communication
User’s Manual commands and program functions.
(Vol 2/2)

Notes

• The contents of this manual are subject to change without prior notice as a result
of improvements in the instrument’s performance and functions. Display contents
illustrated in this manual may differ slightly from what actually appears on your screen.

• Every effort has been made in the preparation of this manual to ensure the accuracy
of its contents. However, should you have any questions or find any errors, please
contact your nearest YOKOGAWA dealer.

• Copying or reproducing all or any part of the contents of this manual without the
permission of Yokogawa Electric Corporation is strictly prohibited.

• A warranty sheet is included. It cannot be reissued. After reading the sheet, keep it in
a safe location.

Trademarks

• Microsoft and Windows are trademarks or registered trademarks of Microsoft
Corporation in the United States and/or other countries.

• Adobe, Acrobat, and PostScript are trademarks or registered trademarks of Adobe
Systems incorporated.

• The company and product names used in this manual are not accompanied by the
trademark or registered trademark symbols(TM,

)

• Other company and product names are trademarks or registered trademarks of their
respective companies.

Revisions

• 1st Edition: August 2008

1st Edition : August 2008 (YK)
All Rights Reserved, Copyright © 2008 Yokogawa Electric Corporation

ii

IM 735302-01E

Checking the Contents of the Package

After opening the package, check the following items before beginning use. If any of the
contents are incorrect, missing, or appear to be abnormal, please contact your Yokogawa
dealer or representative.

AQ6370B Main Unit

Check that the model and suffix code on the name plate on the rear of the instrument
match those of your order. When contacting the dealer from which you purchased the
instrument, please give them the instrument number.

MODEL Suffix Code Description

735302 Optical Spectrum Analyzer AQ6370B
Power cord -D UL/CSA standard power cord (part no.: A1006WD),

maximum rated voltage: 125 V

-F VDE standard power cord (part no.: A1009WD),
maximum rated voltage: 250 V

-R AS standard power cord (part no.: A1024WD),
maximum rated voltage: 250 V

-Q BS standard power cord (part no.: A1054WD),
maximum rated voltage: 250 V

-H GB standard power cord (complies with the CCC)
(part no.: A1064WD), maximum rated voltage: 250 V

Options /FC AQ9447 (FC) connector adapter (for optical input)
/SC AQ9447 (SC) connector adapter (for optical input)
/ST AQ9447 (ST) connector adapter (for optical input)
/RFC AQ9441 (FC) universal adapter (for calibration light source

output)

/RSC AQ9441 (SC) universal adapter (for calibration light source

output)

/RST AQ9441 (ST) universal adapter (for calibration light source

output)

/B5 Built-in thermal printer

• No. (Instrument Number)

Please contact your nearest Yokogawa representative.

Accessories

Part Name Quantity

Power cord (with 3 to 2 prong adapter) 1
User’s manual 1
Remote control user’s manual 1
Printer roll paper (with /B5 option) 1

Accessories (Sold Separately)

Part Name Model/Part Number Specifications

AQ9447 connector adapter 810804602-FCC FC type (for optical input)
810804602-SCC SC type (for optical input)
810804602-STC ST type (for optical input)

AQ9441 universal adapter 813917321-FCC FC type (for calibration light source output)
813917321-SCC SC type (for calibration light source output)
813917321-STC ST type (for calibration light source output)

Printer roll paper B9988AE Lot size is 10 rolls, 10 meters each

iii

IM 735302-01E

Safety Precautions

This instrument is an IEC safety class I(provided with terminal for protective earth
grounding). The general safety precautions described herein must be observed
during all phases of operation. If the instrument is used in a manner not specified in
this manual, the protection provided by the instrument may be impaired. Yokogawa
Electric Corporation assumes no liability for the customer’s failure to comply with these
requirements.

The following symbols are used on this instrument.

Danger, Refer to the user's manual.

This symbol appears on dangerous locations on the instrument which require
special instructions for proper handling or use. The same symbol appears in the
corresponding place in the manual to identify those instructions.

Alternating current

ON(power)

OFF(power)

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IM 735302-01E

Safety Precautions

Make sure to comply with precautions below. Not complying might result in

injury or death.

WARNING

• Use the Correct Power Supply

Before connecting the power cord, ensure that the source voltage matches the

rated supply voltage of the instrument and that it is within the maximum rated
voltage of the provided power cord.

• Use the Correct Power Cord and Plug

To prevent the possibility of electric shock or fire, be sure to use the power cord

supplied by YOKOGAWA. The main power plug must be plugged into an outlet
with a protective earth terminal. Do not disable this protection by using an
extension cord without protective earth grounding.

• Connect the Protective Grounding Terminal

Make sure to connect the protective earth to prevent electric shock before

turning ON the power. The power cord that comes with the instrument is a
three-prong type power cord. Connect the power cord to a properly grounded
three-prong outlet.

• Do not Impair the Protective Grounding

Never cut off the internal or external protective earth wire or disconnect the

wiring of the protective earth terminal. Doing so poses a potential shock hazerd.

• Do not Operate with Defective Protective Grounding or Fuse

Do not operate the instrument if the protective earth or fuse might be defective.
Make sure to check them before operation.

• Reference light source output light

The instrument has a built-in reference light source for wavelength calibration,

and infrared light is always being output from the optical output connector. Never
look into the optical output connector. Infrared light entering the eyes can cause
severe injury and loss of vision.

• Do not Operate in an Explosive Atmosphere

Do not operate the instrument in the presence of flammable liquids or vapors.
Operation in such environments constitutes a safety hazard.

• Do not Remove Covers

The covers should be removed by YOKOGAWA’s qualified personnel only.
Opening the cover is dangerous, because some areas inside the instrument

have high voltages.

• Laser Class 1

This unit complies with “Class 1M laser product” defined in “IEC60825-1 , 2001”.
Never look at the optical output connector or the top end of the optical fiber

connected to the optical output connector while the infrared light is being output.

If the infrared light output is observed at a distance of 100mm or less from the

infrared light emitting part by means of optical method (loupe, magnifying glass,
microscope, etc.), this may cause eye injury. The infrared light cannot be seen.
However, if the infrared light enters your eye(s), this may cause eye injury and
the eyesight to be ruined excessively.

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IM 735302-01E

Safety Precautions

Safety Precautions for Laser Products

This instrument uses a laser light source. This instrument is a Class 1 laser product
as defined by IEC 60825-1 Safety of Laser Products-Part 1: Equipment Classification,
Requirements and User’s Guide.

CLASS 1 LASER PRODUCT
(IEC 60825-1:2001)

Laser Class 1 Label

If the laser output is observed at a distance of
100mm or less from the laser beam emitting
part by means of optical method (loupe,
magnifying glass, microscope, etc.), this may
cause eye unjury.

Class Laser Type Wavelength Maximum

Output Power

Diameter of
Mode Field

Numerical
Aperture

1 EE-LED 1.55µm 0.04mW 9µm 0.1

Make sure to comply with the precautions below. There are limitations to the

operating environment

CAUTION

This product is a Class A (for industrial environment) product. Operation of this
product in a residential area may cause radio interference in which case the user is
required to correct the interference.

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IM 735302-01E

Waste Electrical and Electronic Equipment

Waste Electrical and Electronic Equipment (WEEE), Directive 2002/96/EC

(This directive is only valid in the EU.)

This product complies with the WEEE Directive (2002/96/EC) marking

requirement. This marking indicates that you must not discard this electrical/

electronic product in domestic household waste.

Product Category

With reference to the equipment types in the WEEE directive Annex 1, this

product is classified as a “Monitoring and Control instrumentation” product.

Do not dispose in domestic household waste. When disposing products in the EU,

contact your local Yokogawa Europe B. V. office.

vii

IM 735302-01E

Conventions Used in This Manual

Safety Markings

The following markings are used in this manual.

Improper handling or use can lead to injury to the user or damage to
the instrument. This symbol appears on the instrument to indicate
that the user must refer to the user's manual for special instructions.
The same symbol appears in the corresponding place in the user's
manual to identify those instructions. In the manual, the symbol is
used in conjunction with the word “WARNING” or “CAUTION.”

WARNING

Calls attention to actions or conditions that could cause serious or
fatal injury to the user, and precautions that can be taken to prevent
such occurrences.

CAUTION

Calls attentions to actions or conditions that could cause light injury to
the user or damage to the instrument or user’s data, and precautions
that can be taken to prevent such occurrences.

Note

Calls attention to information that is important for proper operation of
the instrument.

Notations Used on Pages Describing Operating Procedures

On pages that describe the operating procedures in Chapter 3 through 11, the following
notations are used to distinguish the procedures from their explanations.

Procedure

This subsection contains the operating procedure used to carry out
the function described in the current chapter. All procedures are
written with inexperienced users in mind; experienced users may not
need to carry out all the steps.

Explanation

This subsection describes the setup parameters and the limitations on
the procedures. It may not give a detailed explanation of the function.
For a detailed explanation of the function, see chapter 2.

Notations Used in the Procedures

Panel Keys and Soft keys

Bold characters used in the procedural explanations indicate characters that are marked on the
panel keys or the characters of the soft keys displayed on the screen menu.

Unit

k: Denotes “1000.” Example: 100kS/s
K: Denotes “1024.” Example: 459KB (file data size)

viii

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Flow of Operation

The figure below is provided to familarize the first-time user with the general flow of this
instrument operation. For a description of each item, see the relevant section or chapter.

Preparing for Measurement

Setting Conditions and Measuring

Waveform Display

Installing the Instrument

Turning the Power ON/OFF

Wavelength Calibration

Auto Sweep Setting and Measurement

Other Settings

Waveform Display

Displaying Calculated Waveforms

Marker Display

Searching

Waveform Analysis

Waveform Analysis

GO/NO-GO Judgment

Saving Display Data and Printing Out

Storage Media

Saving Data

Internal Printer(Optional)

Section 3.1

Section 3.4

Section 3.7

Section 5.1

Section 5.2 to 5.11

Section 6.1 to 6.4

Section 6.5

Section 6.8

Section 6.12

Section 7.1 to 7.9

Section 7.12

Section 8.1

Section 8.2 to 8.8

Section 4.6

Measurement Start (Sweep)

External Trigger Measurement

Synchronous Sweep Measurement

Section 5.12

Section 5.15

Section 5.17

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IM 735302-01E

Contents

Checking the Contents of the Package.............................................................................................ii

Safety Precautions ........................................................................................................................... iii

Waste Electrical and Electronic Equipment .....................................................................................vi

Conventions Used in This Manual .................................................................................................. vii

Flow of Operation........................................................................................................................... viii

Chapter 1 Part Names and Functions

1.1 Front Panel ....................................................................................................................... 1-1

1.2 Rear Panel ....................................................................................................................... 1-2

1.3 Panel Keys and Knobs ..................................................................................................... 1-3

1.4 LCD Screen ...................................................................................................................... 1-6

Chapter 2 Functions

2.1 System Structure .............................................................................................................. 2-1

2.2 Measurement ................................................................................................................... 2-2

2.3 Waveform Display ........................................................................................................... 2-7

2.4 Analysis ...........................................................................................................................2-11

2.5 Other .............................................................................................................................. 2-13

Chapter 3 Preparing for Measurement

3.1 Installing the Instrument ................................................................................................... 3-1

3.2 Attaching the Connector Adapter ..................................................................................... 3-3

3.3 Connecting a Communication Interface ........................................................................... 3-5

3.4 Turning the Power ON/OFF .............................................................................................. 3-8

3.5 Connecting the DUT ....................................................................................................... 3-12

3.6 Alignment Adjustment ..................................................................................................... 3-13

3.7 Wavelength Calibration .................................................................................................. 3-15

3.8 Important Points During Measurement ........................................................................... 3-20

Chapter 4 Common Operations

4.1 Description of Soft Keys ................................................................................................... 4-1

4.2 Using the Mouse and External Keyboard ......................................................................... 4-3

4.3 Entering Numerical Values and Strings ............................................................................ 4-5

4.4 Screen Display ................................................................................................................. 4-7

4.5 Setting the Date and Time ................................................................................................ 4-8

4.6 Printing Out Using the Internal Printer (Optional) ............................................................. 4-9

Chapter 5 Mesurement

5.1 Auto Measurement ........................................................................................................... 5-1

5.2 Horizontal/Vertical Axis Settings ....................................................................................... 5-2

5.3 Sub Scale ......................................................................................................................... 5-7

5.4 Setting the Reference Level ............................................................................................5-11

5.5 Center Wavelength (Center Frequency) Setting ............................................................ 5-15

5.6 Sweep Width Settings .................................................................................................... 5-20

5.7 Wavelength (Frequency) Resolution Settings ................................................................ 5-24

5.8 Sampling Point/Interval Settings .................................................................................... 5-27

5.9 Sensitivity Settings ......................................................................................................... 5-29

5.10 Averaging Times Setting................................................................................................. 5-31

5.11 Trace Settings ................................................................................................................ 5-32

1

2

3

4

5

6

7

8

9

10

11

App

Index

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5.12 Measurement Start (Sweep) .......................................................................................... 5-34

5.13 Specifying a Sweep Range ............................................................................................ 5-36

5.14 Pulse Light Measurement ............................................................................................... 5-37

5.15 External Trigger Measurement ....................................................................................... 5-39

5.16 Trigger Output ................................................................................................................ 5-42

5.17 Synchronous Sweep Measurement with the Tunable Laser Source .............................. 5-43

5.18 Analog Out ..................................................................................................................... 5-47

Chapter 6 Waveform Display

6.1 Zooming In/Out on Waveforms ......................................................................................... 6-1

6.2 Wavelength Updating/Fixing ............................................................................................. 6-8

6.3 MAX/MIN HOLD Display ................................................................................................ 6-10

6.4 Sweep Average ...............................................................................................................6-11

6.5 Displaying Calculated Waveforms .................................................................................. 6-13

6.6 Normalized Display ....................................................................................................... 6-18

6.7 Curve Fitting .................................................................................................................. 6-19

6.8 Marker Display ............................................................................................................... 6-25

6.9 Displaying a Split Screen ............................................................................................... 6-36

6.10 Noise Mask ..................................................................................................................... 6-38

6.11 Copying and Clearing Traces ......................................................................................... 6-40

6.12 Searching ....................................................................................................................... 6-42

Chapter 7 Analysis

7.1 Spectrum Width Measurement ......................................................................................... 7-1

7.2 Notch Width Measurement ............................................................................................... 7-4

7.3 SMSR Measurement ........................................................................................................ 7-6

7.4 POWER Measurement ..................................................................................................... 7-8

7.5 DFB-LD, FP-LD, and LED Measurement ......................................................................... 7-9

7.6 PMD Measurement ........................................................................................................ 7-10

7.7 WDM Transmission Signal Analysis ............................................................................... 7-12

7.8 Optical Amp Gain and NF Measurement ........................................................................ 7-19

7.9 Optical Filter Characteristics Measurement ................................................................... 7-26

7.10 Editing the Grid Table ..................................................................................................... 7-35

7.11 Measurement of Level Fluctuations in Single-Wavelength Light (0 nm Sweeping) ........ 7-39

7.12 Go/No-Go Judgment (Template) .................................................................................... 7-42

7.13 Specifying an Analysis Range ........................................................................................ 7-54

7.14 Correcting Displayed Values .......................................................................................... 7-57

Chapter 8 Saving/Loading Data

8.1 USB Storage Media .......................................................................................................... 8-1

8.2 Temporarily Saving and Redisplaying Traces to and from Internal Memory .................... 8-2

8.3 Saving/Loading Displayed Data ....................................................................................... 8-6

8.4 Saving/Loading Setting Data .......................................................................................... 8-21

8.5 Saving/Loading Analysis Results Data ........................................................................... 8-26

8.6 Saving/Loading Program Data ....................................................................................... 8-34

8.7 Saving Screen Image Data ............................................................................................ 8-40

8.8 Saving/Loading Template Data....................................................................................... 8-44

8.9 Creating Files ................................................................................................................. 8-50

Contents

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Chapter 9 Other Operations

9.1 Registering Soft keys ....................................................................................................... 9-1

9.2 Data Initialization .............................................................................................................. 9-2

9.3 Help ................................................................................................................................ 9-15

9.4 Registering and Loading Character Strings ................................................................... 9-16

9.5 Other Settings ................................................................................................................ 9-17

Chapter 10 Maintenance

10.1 Upgrading the Firmware ................................................................................................. 10-1

10.2 Mechanical Inspection .................................................................................................... 10-3

10.3 Operational Inspection ................................................................................................... 10-4

10.4 Inspection of Wavelength Accuracy ................................................................................ 10-5

10.5 Inspection of Level Accuracy .......................................................................................... 10-6

10.6 Replacing Fuses ............................................................................................................. 10-7

10.7 Daily Maintenance .......................................................................................................... 10-8

10.8 Care during Storage ..................................................................................................... 10-10

10.9 Recommended Replacement Parts ..............................................................................10-11

10.10 Warning Display Function ............................................................................................. 10-12

Chapter 11 Specications

11.1 Specications ..................................................................................................................11-1

11.2 External Dimensions .......................................................................................................11-4

Appendix

Appendix 1 GRID Table for WDM Wevelength .....................................................................App-1

Appendix 2 Data Calculation Algorithms for Spectrum Widths .............................................App-2

Appendix 3 Details of Each Analytical Functions ................................................................ App-11

Appendix 4 Detailed Explanations of WDM Analysis Function ...........................................App-18

Appendix5 DetailsofOpticalAmplierAnalysisFunction .................................................. App-29

Appendix 6 Details of Optical Filter Analysis Function ........................................................ App-32

Appendix 7 Soft Key Tree Diagram .....................................................................................App-49

Appendix 8 END USER LICENSE AGREEMENT .............................................................. App-67

Index

Contents

1

2

3

4

5

6

7

8

9

10

11

App

Index

1-1

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1

Part Names and Functions

1.1 Front Panel

Front Panel

AQ6370B

OPTICAL SPECTRUM ANALYZER

USB

POWER

FUNCTION

DATA ENTRY

CENTER

SWEEP

SPAN

LEVEL

ZOOM

SETUP

MARKER

DISPLAY

PEAK

SEARCH

TRACE

ANALYSIS

USER

MEMORY

FILE

SYSTEM

ADVANCE

PROGRAM

OREMOTE

UNDO/
LOCAL

HELP

COPY

FEED

COARSE

7

8

9

4

5

6

123

0

.

-

BACK
SPASE

nm/
ENTER

m/
ENTER

OPTICAL INPUT
(

600 1700nm

)

CALIBRATION
OUTPUT

1 2

3

4

5

6

7

8 9

10

11

12

No. Name Function

1 LCD display Displays measured waveform, measurement conditions,

measurement values, etc.

2 Soft key section Used to execute the functions assigned to the soft keys on

the right side of the LCD display

3 FUNCTION section Used to enter settings pertaining to all measurements

(sweep, measurement conditions, data analysis, and various
functions)

4 DATA ENTRY section Used for measurement condition parameter input, label

input, etc.
5 POWER Used to start and shut down the instrument.
6 USB1.1 interface Used to connect USB storage media
7 UNDO/LOCAL See the following table(1.3 Panel keys and Knobs)
8 HELP Used to check the contents of the soft key menu displayed

on the screen.
9 COPY Used to make hard copies of the screen through the internal

printer (optional)
10 FEED Used to feed recording paper
11 OPTICAL INPUT Optical input connector
12 CALIBRATION OUTPUT Reference light source optical output connector used for

alignment adjustments and wavelength calibration

Chapter 1 Part Names and Functions

1-2

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1.2 Rear Panel

Rear Panel

TRIGGERINTRIGGER

OUT

ANALOG

OUT

SERIAL
(

RS-232

)

ETHERNET

10/100BASE-TX

VIDEO

OUT

(
SVGA

)

KBD

GP-IB1

(

IEEE488.1/488.2

)

GP-IB2

(
IEEE488.1

)

(
FOR TLS,ETC.

)

WARNING

Do no t op era te wi th ou t r ea din g th e
safet y pr eca ut ion s in th e use r’ s man ua l.

MAIN P OWER

ON
OFF

100-240V AC
150VA

MAX

50/60Hz

FUSE

250VT5A

9

10

8 11

3 4

5

1

2

6

7

No. Name Function

1 GP-IB1 GP-IB port for controlling this unit through an external

computer

2 GP-IB2 GP-IB port that allows this unit to serve as a system

controller on the GP-IB bus for controlling an external device

3 TRIGGER IN Input connector for synchronous signals for the synchronous

measurement function with the Tunable Laser Source

4 TRIGGER OUT Output connector for synchronous signals for the

synchronous measurement function with the Tunable Laser

Source
5 ANALOG OUT Analog output
6 MAIN POWER Used to turn the main power ON/OFF
7 Power cord connector Connect the power cord to this connector
8 SERIAL RS-232 interface
9 ETHERNET Ethernet Interface (10/100BASE-TX)
10 VIDEO OUT (SVGA) Analog RGB video signal (SVGA-compliant) interface
11 KBD External keyboard interface (PS/2)

1-3

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1

Part Names and Functions

1.3 Panel Keys and Knobs

FUNCTION Section

The FUNCTION section contains 17 function keys and 4 auxiliary keys. When you press
a function key, information about the function is displayed on the soft key menu located
on the right side of the LCD display.

SWEEP

The SWEEP key contains functions related to sweeping. When you press the SWEEP
key, the soft key menu for sweeping appears.

CENTER

The CENTER key contains functions related to setting the center wavelength and center
frequency for measurements. The soft key functions change depending on whether the
screen display mode is wavelength display mode or frequency display mode.

SPAN

The SPAN key contains functions pertaining to settings for the wavelength span or
frequency span being measured. The soft key functions change according to whether the
screen display mode is wavelength display mode or frequency display mode.

LEVEL

The LEVEL key contains functions related to level axis settings.When you press the
LEVEL key, the soft key menu for setting reference level appears.

SETUP

The SETUP key contains functions related to measurement condition settings.

ZOOM

The ZOOM key contains the zoom function, which allows the user to freely enlarge or
reduce a measured waveform in order to check a small area of the measured waveform,
or to check the overall waveform.
This key is used to set the waveform enlarged/reduced display conditions.

DISPLAY

The DISPLAY key contains functions related to screen display.This key is used to set the
screen to upper/lower 2-split display mode (split mode).

TRACE

The TRACE key contains functions related to trace mode settings.

MARKER

The MARKER key contains functions related to markers.

PEAK SEARCH

The PEAK SEARCH key contains functions for searching for peaks and bottoms in
measured waveforms.

ANALYSIS

The ANALYSIS key contains functions related to measured waveform analysis.

FUNCTION

CENTER

SWEEP

SPAN

LEVEL

ZOOM

SETUP

MARKER

DISPLAY

PEAK

SEARCH

TRACE

ANALYSIS

USER

MEMORY

FILE

SYSTEM

ADVANCE

PROGRAM

OREMOTE

UNDO/
LOCAL

HELP

COPY

FEED

1-4

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MEMORY

The MEMORY key contains functions for writing the contents of the active trace to the
unit’s internal memory. When you press the MEMORY key, the traces and memory list
screen (soft key menu) are displayed. A memory number may be entered in the DATA
ENTRY section, or selected using the rotary knob or arrow keys.

FILE

The FILE key contains functions for saving and loading waveform data, program data,
and the like to and from USB storage media (USB memory/HDD).

PROGRAM

The PROGRAM key contains the soft keys related to program functions for controlling
measurements through a program.

SYSTEM

The SYSTEM key contains system-related functions such as monochromator adjusting
optical alignment, wavelength adjustment, hardware setup, and setting initialization.

ADVANCE

The ADVANCE key contains functions related to template function settings.

USER

Frequently used soft keys can be registered on the soft key menu in the USER key.
Registering frequently used soft keys in the USER key allows you to execute frequently
used functions in a small number of steps.

COPY/FEED

The COPY key is used to output the measurement screen to the internal printer or a file.
When you press the COPY key, the measured waveforms and lists displayed on the
screen are output to the internal printer or a file.
The FEED key is used to feed printer paper. Paper feeding continues as long as you hold
down the FEED key.

UNDO/LOCAL

The key's function changes depending on the status of the instrument when the UNDO/
LOCAL key is pressed. The following table shows the key's functions.

Status of Instrument Function

UNDO action is allowed If the UNDO key is pressed after changing parameter

settings, changing or deleting data, etc., the previous
action (change, deletion, etc.) is canceled and the state
preceding that action is restored.

During user key registration If the UNDO key is pressed during user key registration,

registration mode is canceled and the soft key menu
which appeared when the SYSTEM key was pressed is
displayed again.

During remote control by
external PC (Remote light is on)

Changes the state from the remote state back to the
local state. The remote light turns off.

HELP

When you press the HELP key, a soft key menu of the currently displayed screen is
displayed explanations.
Soft keys for selecting the “MORE INFO” which indicate additional information are
displayed by some soft keys in HELP screen.

1.3 Panel keys and Knobs

1-5

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1

Part Names and Functions

DATA ENTRY Section

This unit allows you to enter measurement conditions and various other parameters
through the DATA ENTRY section. Three different entry methods can be used in the
DATA ENTRY section, the rotary knob, the arrow keys, and the numeric keypad.

Rotary knob

When you press a soft key which has a parameter, the current setting is displayed in
the parameter entry window. Turning the rotary knob raises or lowers the numeric value
shown in the parameter entry window (turn clockwise to increase and counterclockwise
to decrease), and the internal setting changes at the same time.
Note that if the COARSE key is on (lamp on), the numeric value increase/decrease step
will be larger.

Arrow keys (▲, ▼)

Pressingthe▲keyhasthesameeffectasturningtherotaryknobclockwise.Likewise,
pressingthe▼keyhasthesameeffectasturningtherotaryknobcounterclockwise.

Holding an arrow key down for 0.5 second or longer activates auto-repeat.
If the multi-marker function has been selected, the arrow keys can be used to scroll the
marker value display in the data area.

COARSE Key

You can raise the digit of settings being entered or the increase/decrease step for
numerical values.
Each time you press this key the setting toggles between ON and OFF. When ON, the
lamp lights.

Numeric keypad

You can enter numerical values directly into the parameter input window by pressing
keys of the numeric keypad.
After you have pressed a parameter soft key to display the current setting in the
parameter display area, you can press a numeric keypad key to display the numeric
keypad input area including the entered numeric value.
If the value entered with the numeric keypad is not in the allowed value range, the
nearest allowed value will be set.

μm/ENTER Key and nm/ENTER Key

Enters values input using the numeric keypad or the parameter input window.
Use one or the other key if entering a parameter value with a particular unit.

Ifaparameterdoesnothaveaunitassociatedwithit,youcanuseeithertheμm/ENTER

key or the nm/ENTER key.

BACK SPACE Key

Use this key if you make an error when inputting values with the numeric keypad. The
last entered (right-most) character is removed, allowing entry of the correct character.
By holding the BACK SPACE key down, you can erase the entire entry in the numeric
keypad input area and make the numeric keypad input area disappear, returning it to the
condition preceding numeric keypad input.

1.3 Panel keys and Knobs

DATA ENTRY

COARSE

7

8

9

4

5

6

1

2

3

0

.

-

BACK

SPASE

nm/

ENTER

m/

ENTER

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1.4 LCD Screen

1

2

3

4

5

6

7

8

9

10

11

12

13

14 15

16

17

18

19

20

21

22

No. Function

1 Data area
2 Measurement conditions area

3

(Displayed when any of the measurement conditions are changed.)

4 Displays level axis scale per DIV
5

(Displayed when measurement is not correctly carried out.)

6 Displays reference level
7 Label area (56 characters)
8 Displays wavelength resolution
9 Displays measurement sensitivity
10 Displays averaging times
11 Displays the number of measurement samples
12 Displays date and time
13 Displays each trace status

14

(Only displayed when ZOOM function is used)

15 Displays the statuses of main settings (When a setting is ON, its display is depressed, or

is displayed with white on black background if the display colors are black and white.)
16 Displays wavelength axis scale per DIV
17 Displays sweep status
(RPT=Repeat; SGL=Single; STP=Stop)
18 Displays soft key menu
(Displays markers and data analysis results.)

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1

Part Names and Functions

19 Parameter display area
20 Parameter input area
21 OVERVIEW display screen
(Only displayed when ZOOM function is used.)
22 Displays sub-scale

1.4 LCD Screen

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2

Chapter 2 Functions

2.1 System Structure

System Structure

AQ6370

OPTICAL SPECTRUM ANALYZER

USB

POWER

FUNCTION

DATA ENTRY

CENTER

SWEEP

SPAN

LEVEL

ZOOM

SETUP

MARKER

DISPLAY

PEAK

SEARCH

TRACE

ANALYSIS

USER

MEMORY

FILE

SYSTEM

ADVANCE

PROGRAM

OREMOTE

UNDO/
LOCAL

HELP

COPY

FEED

COARSE

7

8

9

4

5

6

123

0

.

-

BACK
SPASE

nm/
ENTER

m/
ENTER

OPTICALI NPUT
(
600 1700nm

)

CALIBRATION
OUTPUT

Splitter cable

PS/2 mouse

PS/2 mouse

PS/2 keyboard

Control target Control target

GP-IB2 interface

GP-IB2 interface
RS-232 interface
Ethernet interface

USB mouse

USB storage
medium

PC

Analog output

Built-in printer
(optional)

External trigger input

Video signal output
trigger output

2-2

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2.2 Measurement

Alignment Adjustment <<See section 3.6 for the operating procedure>>

This function allows adjustment of the optical axis of the instrument’s built-in
monochromator (spectroscope).
The instrument’s optical performance is not guaranteed until the alignment adjustment
function has been executed. Failure to perform this adjustment can result in distortion
of measured waveforms. After alignment adjustment has been executed, wavelength
calibration is also subsequently performed automatically. If you are using the instrument
for the first time or using it after it has been severely shaken while being moved, perform
the alignment adjustment procedure after warm-up ends.

Wavelength Calibration <<See section 3.7 for the operating procedure>>

Wavelength calibration can be performed using the internal reference light source or an
external light source.

Auto Measurement <<See section 5.1 for the operating procedure>>

This function automatically sets the optimal measuring conditions for the input light and
displays the spectrum waveform. This function is useful when the characteristics of the
input light are not well known.
The wavelength range of input light that can be auto-measured is 1200–1670 nm.
The measurement conditions that are set automatically are as follows.

1. Span (SPAN)

2. Center wavelength (CENTER)

3. Reference level (REF LEVEL)

4. Resolution (RESOLUTION)
Other measuring conditions (sensitivity, averaging times, number of sampling points,
and interval settings) are set to their defaults. The horizontal and vertical axes of the
displayed spectrum waveform are zoomed to an appropriate degree.

Single Sweep <<See section 5.12 for the operating procedure>>

This function executes a single sweep or forcibly stops a sweep operation.

Repeat Sweep <<See section 5.12 for the operating procedure>>

This function performs repeat sweeping or forcibly stops a sweep operation. It enables
repeated, real-time measurement of waveforms.

Segment Measurement <<See section 5.12 for the operating procedure>>

This function allows you to divide up items to be measured in units of previously specified
segments.
Allows measurement delimited by segments (portions).

Synchronous Sweep <<See section 5.17 for the operating procedure>>

This function links the turnable laser source connected to the GP-IB2 port with the sweep
of the instrument. By synchronizing sweep with the turnable laser source, measurement
of high resolution and optical dynamic ranges can be obtained when measuring the
wavelength loss characteristics of optical filters, optical fiber gratings, and other items.

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2

Higher resolution can be obtained since the wavelength resolution is being determined
by the spectral line width of the tunable laser source. Also, since the tunable laser source
scarcely outputs any other components than the measuring wavelength, and as the noise
light which comes out faintly is being totally cut except for the section corresponding to
the resolution range of this equipment, an extremely high optical dynamic range can be
acquired.

This instrument can execute synchronous sweep with the following tunable laser
sources.

• AQ4321 Series Tunable Laser Source

• AQ2200-136 Tunable Laser Source

One-Action Keys <<See section 5.4 to 5.6 for the operating procedure>>

This is the general name for a key that uses data from the active trace waveform (the
currently displayed waveform) to set measurement conditions.
Setting conditions requires that a waveform is displayed for the active trace.

One-Action Key Name Description

PEAK→REFLEVEL Setsthepeaklevelofthemeasuredwaveformoftheactivetrace

as the reference level.

MARKER→REFLEVEL Setsthemovingmarkerlevelasthereferencelevel.

PEAK→CENTER  Setsthepeakwavelengthorthepeakfrequencyoftheactive

trace measurement waveform to center wavelength or center
frequency.

MEANWL→CENTER SetsTHRESH3dBcenterwavelengthorcenterfrequencyofthe

active trace measured waveform to center wavelength or center
frequency.

VIEW→MEAS   SetsthecurrentlydisplayedZOOMscale

as the measurement

scale (CENTER, START, STOP, SPAN) for the next sweep.

MARKER→CENTER Setsthewavelengthofthemovingmarkertocenterwavelengthor

center frequency.

Δλ→SPAN    Setsthe

sweep width as six times the RMS 20 dB width of the

active trace measurement waveform.

MKRL1-L2→SPAN Setsspacingbetweenlinemarkers1and2forsweepwidth.

PEAK→ZOOMCTR Sets the peak wavelength of the active trace measurement

waveform to center wavelength or center frequency of zoom
display.

MARKER→ZOOMCTR Setsthewavelengthofthemovingmarkertocenterwavelengthor

center frequency of zoom display.

MKRL1-L2→ZOOMSPAN Sets spacing between line markers 1 and 2 for sweep width of

zoom display.

Switching between Vacuum Wavelength and Air Wavelength

<<See section 5.2 for the operating procedure>>

This function switches the measured wavelength to either a vacuum wavelength or an air
wavelength.
Measurement can be performed in either air or vacuum wavelength mode.

Switching between Wavelength and Frequency

<<See section 5.2 for the operating procedure>>

This function switches the horizontal axis display to wavelength or frequency.
You can display either the wavelengths or frequencies of marker values and analysis
results.

2.2 Measurement

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Averaging <<See section 5.10 for the operating procedure>>

This function performs multiple measurements and displays the average values.
The function is used in cases such as: when the light source’s level is fluctuating; when
measuring a modulated signal of several kHz or less; when the waveform is disrupted
and difficult to measure; when it is necessary to obtain even higher measurement
sensitivity.

Power Density Display <<See section 7.4 for the operating procedure>>

The power per 1 nm is called the power density.
The level axis of the AQ6370B indicates the absolute power per wavelength resolution.
For example, if the resolution is set to 0.1 nm, the power per 0.1 nm will be displayed.
Since the optical spectrum of such devices as a gas laser or a laser diode is narrower
than the wavelength resolution of the instrument, the entire power is accommodated
within the band of a resolution. Therefore, the measured power (peak level) is equal
to the total power of the light source. This instrument has been calibrated to display
accurate power under such conditions.

On the other hand, natural light or lights such as fluorescent lamps or LEDs, have,
in many cases, optical spectrums wider than the wavelength resolution set for the
instrument. Therefore, if the instrument measures these lights, measured power will vary,
depending on the resolution setting.

In order to deal with this issue, the instrument is equipped with the dBm dBm/nm soft key

toallowthelevelaxisdisplaystoswitchfromtheabsolutepower(dBm,mW,μW,nW,
pW)perresolutiontopowerdensity(dBm/nm,mW/nm,μW/nm,nW/nm,pW/nm).

In the case of power density displays, a measured value is converted to power per 1 nm.
Therefore, whatever resolution is used for measurement, certain measured values will
always be available.
Differences in usage between the absolute power display and the power density display
are shown below:

Absolute power display: measurement of light sources with narrow spectrum widths,
such as gas lasers or laser diodes.
Power density display: measurement of light sources with wide spectrum widths, such as
natural light or LEDs.

IfthesubtractionfunctionbetweentracesisusedforsuchcasesasA-B(A/B)→Cor
B-A(B/A)→C,resultswillbethesamewhethertheabsolutepowerdisplayorthepower

density display is used.
Since the power measurement function performs different calculations according to the
level axis display, correct results will be available whichever display is employed.

Note that, if the NF measurement function (ANALYSIS 2 EDFA-NF soft key) and the
WDM analysis function (ANALYSIS 2 WDM soft key) are executed, the level axis display
will be forcibly changed to the absolute power display.

Note

Specifications such as level accuracy, measurement level range, and level linearity of the
instrument are provided for the absolute power display.

2.2 Measurement

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External Trigger Measurement <<See section 5.15 for the operating procedure>>

This function performs measurement in synchronization with an external trigger signal.
The SMPL TRG IN terminal is an input terminal on the TTL level and in positive/
negative logic (which can be set by the <EXT TRIGGER SETTING> key). The SMPL
TRG IN terminal is an input terminal for TTL level, positive/negative logic signals. The
measurement points (wavelength/frequency) are incremented each time edges of input
external trigger signals are detected. Thus, sweeping stops when a number of external
trigger signals equaling the specified number of sampling points is input. (However,
when the REPEAT sweep is performed, the sweep will be repeated until the STOP key is
pressed or until trigger signals are no longer input.)
The delay time (from the time when a trigger signal is detected until the time when the
sampling is performed) specific to the instrument is about 20 µs. Supply the trigger
signal at a timing appropriate for the measurement sensitivity. An optional delay time can
be set to this specific delay time. With the DELAY key of the EXT TRIGGER SETTING
key, the 0.0 µs to 1000.0 µs range can be set in units of 0.1 µs.
Note that after the measurement points are set, input trigger signals during the
movement to the next measurement point are ignored. The time varies depending on the
measurement wavelength band and the number of sampling points (sampling intervals).
Since the SMPL TRG IN terminal is pulled up internally, it can be set to the HIGH level
while it is in the open state and to the LOW level while it is in the GND short state.

Sweep Trigger <<See section 5.15 for the operating procedure>>

This function performs a single sweep measurement based on an externally input trigger
signal.
The instrument starts a single sweep measurement by allowing sweep trigger signals on
the TTL level and in negative logic to enter the TRGGER IN terminal at the back of the
instrument.
The signal logic of the sweep trigger input signals is fixed to negative logic, which cannot
be changed.
The pulse width of sweep trigger signals must be 5 ms or more.
The action when entering a sweep trigger is the same as that for the SWEEP key or
SINGLE key.
The sweep trigger function detects sweep trigger signals by polling in certain cycles.
Thus, the time after a sweep trigger signal is input until the sweep starts will fluctuate in
the range of 5 ms.

Trigger Output <<See section 5.16 for the operating procedure>>

This function outputs trigger signals from the trigger output terminal on the rear panel of
the instrument (only during sweeping).

2.2 Measurement

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Analog Out <<See section 5.18 for the operating procedure>>

An analog voltage is output from the ANALOG OUT terminal on the rear panel of the
main unit according to the input light.
The temporal changes in the input light can be measured by an oscilloscope.
However, to enable this output, the sensitivity setting must be NORM/HOLD.
When set to NORM/HOLD, the RANGE is switched relative to the REF LEVEL without
implementing the AUTORANGE function. Therefore, if the level of the input light is high,
the output voltage level is saturated.
The saturation level and noise level varies depending on the REF level.
The table below shows the relationship between the REF level and the saturation level.

REF LEVEL(dBm or dBm/nm) Saturation Level * (dBm)

REF > 0 23 dBm or more
0 < = REF > -10 13 dBm or more

-10 < = REF > -20 3 dBm or more

-20 < = REF > -30 -7 dBm or more

-30 < = REF -17 dBm or more

* At wavelength 1450 to 1620 nm

ANALOG OUT Output Specifications

Output saturation voltage +6 V or more
Offset voltage (including noise) ±5 mVp-p
Bandwidth 10 kHz or more
Load 1 k

Ω

or more

2.2 Measurement

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2.3 Waveform Display

Zoom <<See section 6.1 for the operating procedure>>

This function allows you to zoom freely in and out on measured waveforms.
You can easily zoom an area simply by selecting it with the mouse. Drag the mouse over
an area of the displayed waveform to zoom in on the area. ZOOMING is displayed at the
bottom of the screen to indicate that the screen is displaying a zoomed area. You can
also zoom in and out with key operations.

Overview <<See section 6.1 for the operating procedure>>

This function displays an overview window at the very bottom of the waveform display
area. The overview window is displayed when the waveform display is enlarged or
reduced using the zoom function. (Only displayed when a zoom is performed.)
You can easily check which part of the measured waveform is zoomed. The overview
window can be shown or hidden, and you can change its position and size.

Trace <<See section 5.11 for the operating procedure>>

A trace shows a waveform and measurement conditions. The instrument has a total of
seven independent traces (A through G). Multiple traces can be displayed at the same
time on the waveform screen. In addition, display ON/OFF and mode settings can be set
separately for each trace.

Traces can be set to the following modes.

• WRITE mode Section 6.2

• FIX mode Section 6.2

• MAX/MIN HOLD mode Section 6.3

• ROLL AVG mode Section 6.4

• CALCULATE mode Section 6.5

The following explains each of the modes.

WRITE Mode

Waveform data are written during sweeping.
When a trace is set to WRITE mode, waveform data are written during measurement,
and the data are updated. Traces used in measurements are normally set to WRITE
mode. The trace display at the side of the data area changes to “WRITE.”

FIX Mode

Fixes the data; does not write waveform data.
When a trace is set to FIX mode, its waveform data are not overwritten even when
measurement is performed. Therefore, the waveform on the screen is not overwritten. If
you want to fix the waveform data of a trace, set the trace to FIX mode. The trace display
at the side of the data area changes to “FIX.”

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MAX/MIN HOLD Mode (Maximum/Minimum Value Detection Mode)

Writes the maximum/minimum values of the waveform data for each sweep.
When a trace is set to MAX/MIN HOLD mode, each time a sweep is performed, the data
at the individual measurement points are compared with prior measurements, and the
measurement with the higher level (MAX HOLD) or lower level (MIN HOLD) is written.
If you want to measure the maximum or minimum value of a waveform which changes
each time a sweep is performed, set the trace you want to measure to MAX/MIN HOLD
mode and perform REPEAT sweeping.
The trace display at the side of the data area appears as “MAX HOLD” or “MIN HOLD”.
Note that the NOISE MASK soft key setting applies when a waveform is displayed, and
is not affected when a maximum or minimum value is detected.

ROLL AVG Mode (Rolling Average Mode)

Writes the rolling average values of the waveform data during each sweep.
When a trace is set to ROLL AVG mode, each time measurement is performed the rolling
average of the current measurement and past measurements is calculated, and the
measurement data are updated. The number of averagings is set in the range of 2 to

100. The trace display at the side of the data area changes to “ROLL AVG”.

CALCULATE Mode (Calculation Results Display)

Writes the results of calculations performed between data from different traces.
When a trace is set to CALCULATE mode, subtraction between data from different
traces, normalized display, or curve-fit display is performed according to the set
CALCULATE mode. Note that CALCULATE mode can only be set for traces C, F, and
G. Also, the available calculations vary from trace to trace. For more information, see
chapter 6.

Normalized Display Function <<See section 6.6 for the operating procedure>>

This function is one of the trace CALCULATE modes. It normalizes and displays the
trace data.
With normalized display, normalization is performed and the waveform is displayed with
the waveform peak set to 1 if the sub-scale is linear, or set to 0 dB if the sub-scale is
LOG. One trace can be normalized, either trace A, B, or C. If both traces selected for
calculation are set to “BLANK”, then the sub-scale is displayed on the left side of the
screen. Otherwise it is displayed on the right side. The calculation results are displayed
in the sub-scale. The trace display at the side of the data area changes to “NORM @”.

Curve Fit <<See section 6.7 for the operating procedure>>

Makes an approximation of the specified trace waveform. The result is written to TRACE G.
Calculations are applied to data from the peak to the threshold value. The threshold
value is set in the range of 0 to 99 dB (steps of 1). The trace display at the side of the
data area changes to “CRV FIT @.”

Peak Curve Fit <<See section 6.7 for the operating procedure>>

Makes an approximation of the specified trace waveform. The result is written to TRACE G.
Calculations are applied to mode peaks at or above the threshold value. The threshold
value is set in the range of 0 to 99 dB (steps of 1). The trace display at the side of the
data area changes to “PKCVFIT @”.

2.3 Waveform Display

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Marker Functions <<See section 6.8 for the operating procedure>>

Marker functions can be used to easily measure wavelength differences and level
differences, and to search for peak wavelengths, peak levels, and spectrum widths.
There are markers and line markers.

Markers

A total of 1025 markers (one moving marker and 1024 fixed markers) are provided.
Moving markers can be moved to an arbitrary wavelength using the rotary knob, arrow
keys, or numeric key pad. You can also drag the markers with the mouse. Moving
markers can be moved over a waveform to display the marker values (wavelength
and level value) in the data area. If a moving marker is fixed in an arbitrary position, it
changes to a fixed marker.
Fixed markers are markers fixed to a number on which the moving marker was set. Fixed
markers are assigned marker numbers in order starting from 001. You can enter an
arbitrary number using the rotary knob, arrow keys, or numeric key pad. A number up to
1024 can be set. When multiple fixed markers are set, it is possible to display wavelength
differences and level differences between a given marker and adjacent markers.

Line Markers

There are four line markers––two wavelength line markers and two level line markers.
Wavelength line markers show wavelength and wavelength difference, and level line
markers show level values and level difference. Also, you can use line markers to specify
a sweep or analysis range.

Displaying Wavelength Difference and Level Difference

This function places a fixed marker and measures the wavelength difference and level
difference compared to a moving marker.

Note

For details, see the explanation in section 6.8, “Displaying Markers.”

Displaying Line Markers

When line markers are displayed, the marker values are shown in the upper left part of
the waveform area.
When both wavelength line markers 1 and 2 are displayed, or both level line markers
3 and 4 are displayed, the wavelength difference (L2-L1) or level difference (L4-L3) is
shown below the marker values.

Note

For details, see the explanation in section 6.8, “Displaying Markers.”

Split Display <<See section 6.9 for the operating procedure>>

You can split the screen into an upper and lower display (SPLIT mode).
You can assign trace waveforms to either the upper or lower split.
TRACE A UP/LOW
This function is used to set whether to put trace A on top or on bottom during upper/lower
split display. If you select UP, it is assigned to the top. (Default) If you select LOW, it is
assigned to the bottom.

2.3 Waveform Display

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Noise Mask <<See section 6.10 for the operating procedure>>

This key is used to display a waveform so that parts of the waveform at or below the
set value are masked. In addition, when a noise mask value is set, the waveform is
overwritten in real time.
When you press the NOISE MASK soft key, the current noise mask value is displayed in
the noise mask value setting screen. The allowed settings for the noise mask setting are
OFF (-210 dBm), and the range from -100 to 0 dBm (fine: in steps of 1; coarse: in steps
of 10).

Peak/Bottom Search <<See section 6.12 for the operating procedure>>

Sets a moving marker at the waveform peak (maximum level value) or bottom (minimum
level value), and displays that value. You can also search for the next peak or bottom.
There is also an auto search function that automatically performs peak/bottom searches
each time sweeping is performed. It is very useful for purposes such as observing peak/
bottom level changes during repeat sweeping.

2.3 Waveform Display

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2.4 Analysis

Spectrum Width Analysis <<See section 7.1 for the operating procedure>>

You can display the spectrum width and center wavelength using the following four types
of calculation.

• THRESH method

• ENVELOPE method

• RMS method

• PEAK RMS method

<See appendix 2, “Spectrum Width Data Calculation Algorithms” for a description of the
spectrum width analysis algorithms and parameters.>

Notch Width Measurement <<See section 7.2 for the operating procedure>>

With notch width measurement, it is possible to measure pass band width / notch
width from the measured waveform of a filter with V-character type or U-character type
wavelength characteristics.

<For a description of the notch width analysis algorithm and parameters, see appendix 2,
“Data Calculation Algorithms for Spectrum Widths.”>

Device Analysis <<See section 7.3 and 7.4 for the operating procedure>>

Light source parameters can be analyzed from the measured waveform of each light
source (DFB-LD, FP-LD, LED).

DFB-LD SMSR Measurement

The side-mode suppression ratio (SMSR) can be measured from the DFB-LD measured
waveform.

FP-LD and LED TOTAL POWER Measurement

Optical power can be measured by integrating the measured waveform level
measurements.

PMD Measurement <<See section 7.6 for the operating procedure>>

It is possible to measure the polarization mode dispersion (PMD) of a DUT (such as
an optical fiber) by using the instrument in combination with an analyzer, polarization
controller, polarizer, and an amplified spontaneous emission (ASE) light source, high­output LED light source, or other wideband light source.

WDM Analysis <<See section 7.7 for the operating procedure>>

You can analyze WDM transmission signals. You can also measure OSNR of a DWDM
transmission system with 50 GHz spacing. Measurements of WDM signal wavelength,
level, wavelength interval, and OSNR can be made collectively on up to 1024 channels,
and the analysis results can be displayed in a data table.

Optical Amp Analysis <<See section 7.8 for the operating procedure>>

Measurement can be performed of the optical amp gain and noise figure from measured
waveform of the signal light going into the optical amp, as well as the measured
waveform of the output light leaving the optical amp.

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Optical Filter Characteristics Measurement

<<See section 7.9 for the operating procedure>>

Optical filter characteristics can be measured from the measured waveform of the light
input to the optical filter from the light source, as well as from the measured waveform
light output from the optical filter.
Analysis can be performed not only on optical filters with only one mode, but also multi­mode WDM filters.

Measurement of Level Fluctuations in Single-Wavelength Light

<<See section 7.11 for the operating procedure>>

This function is used to measure changes over time in the level of a specific wavelength
level. The sweep width is set to 0 nm, and measurement of the single-wavelength light is
taken. The horizontal axis is the time axes. It is useful for purposes such as optical axis
alignment when a light source is input to an optical fiber.

Template <<See section 7.12 for the operating procedure>>

The template function compares preset reference data (template data) with a measured
waveform. In addition, if a function for displaying the target spectrum (target line) on the
measurement screen is used, the target spectrum can be referenced while adjusting the
optical axis of an optical device.

The following three templates are provided.

• Upper limit line

• Lower limit line

• Target line

Go/No Go Judgment <<See section 7.12 for the operating procedure>>

The Go/No Go test function compares the active trace waveform against reference data
(template data) preset by the user, and performs a test on the measured waveform (Go/
No Go test).
The template function can be used effectively in situations such as pass/fail tests on
production lines.

Analysis between Line Markers

<<See section 7.13 for the operating procedure>>

You can specify an analysis range with line markers. Analysis is performed in the range
outlined by the two line markers.

Analysis in the Zoom Area <<See section 7.13 for the operating procedure>>

You can specify the zoomed area as the analysis range.
For example, there is a zoom area power measurement function. This function calculates
totalized power between display scales. It is effective for purposes such as ASE
evaluation on optical amplifiers.

2.4 Analysis

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2

2.5 Other

Using the USB Mouse <<See section 4.2 for the operating procedure>>

With a connected USB mouse you can perform the same operations as with the
instrument’s panel keys. Also, if you move the mouse pointer over the item in the menu
screen that you wish to select and click it, the instrument responds exactly as if you had
pressed the corresponding soft key.
The USB mouse is connected to the connector on the front panel of the instrument.

Registering Soft Keys <<See section 9.1 for the operating procedure>>

Frequently used soft keys can be registered in the soft key menu.
Registering soft keys reduces the steps needed to execute their functions. Twenty-four
soft keys can be registered. By default, all keys are unregistered.

Data Initialization <<See section 9.2 for the operating procedure>>

You can restore all settings to their factory defaults.
The parameter setting values and data of each function are initialized.

Help <<See section 9.3 for the operating procedure>>

Displays an explanation of the soft key menus.
Certain soft keys have additional help text (“MORE INFO”). MORE INFO contains
detailed explanations of the corresponding soft keys.

Remote (Separate Document)

An external device can be connected to the instrument through the GP-IB port or another
port to remotely control the instrument. This function requires a special connector cable
for connecting with the external device. For details, see the separate user’s manual,
“Remote/Program Function.”

Program (Separate Manual)

The program function allows you to control an external instrument without using a PC.
The function uses Ethernet, RS-232, or GP-IB. For details, see the separate user’s
manual, “Remote/Program Function.”

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Chapter 3 Preparing for Measurement

3.1 Installing the Instrument

WARNING

The instrument has a built-in reference light source for wavelength calibration, and
infrared light is always being output from the optical output connector. Never look
into the optical output connector. Infrared light entering the eyes can cause severe
injury and loss of vision.

CAUTION

• Do Not Apply Shock to the Instrument

non-horizontal orientation, and do not drop the instrument from a height of 2 cm

or more. This can adversely affect the accuracy of the internal monochromator
and inhibit performance. Take great care when transporting the instrument, and
use packaging with a shock absorbing capacity that is greater than or equal to
the packaging used upon shipment from the factory.

Never use inferior packaging materials that are unable to sufficiently absorb

vibrations and shocks occurring during transport. This can adversely affect the
accuracy of the internal monochromator and inhibit performance.

• When unpacking

When the instrument is packaged in a box and moved, prevent condensation by

allowing sufficient time for the instrument to acclimatize before removing it from
the box.

Installation Conditions

Install the instrument so that the following conditions are met.

Flat Horizontal Location

Place the instrument in a stable location that is flat in all directions. If the instrument is
used in an unstable or angled surface, the accuracy of the internal monochromator can
be compromised.

Location without Vibration

Do not install the instrument in a location subject to vibration. Use in a location that
experiences large vibrations can lead to instability of operation, measurement stopping
before completion, or notable decreases in accuracy of the wavelength and level axes.

Well Ventilated Location

Ventilation holes are present at the sides and rear of the instrument. To keep the
internal temperature from rising, always maintain a gap of 200 mm or more between the
ventilation holes and the installation surfaces.

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3.1 Installing the Instrument

Also be sure to maintain sufficient clearance for connecting measurement cables, and
opening and closing the cover of the built in printer.

20 cm or
more

AQ6370

OPTICAL SPECTRUM ANALYZER

20 cm or
more

20 cm or
more

20 cm or
more

Ambient Temperature and Humidity

Ambient temperature: 5–35°C
Ambient humidity: 80% RH or lower (no condensation present)

Note

Condensation may occur if the instrument is moved to another place where the ambient
temperature is higher, or if the temperature changes rapidly. In such cases, allow sufficient time
for the instrument to adjust to the ambient temperature before use.
When the instrument is packaged in a box and moved, prevent condensation by allowing
sufficient time for the instrument to acclimatize before removing it from the box.

Do Not Install the Instrument in the Following Places

• Dangerous locations where flammable or explosive gasses, vapors, or dust is present,
or where the possibility of explosions or fires exists.

• In direct sunlight or near heat sources.

• Where an excessive amount of soot, steam, dust, or corrosive gas is present.

• Location where mechanical vibration is high.

• In an unstable place.

General Handling Precautions

• Do Not Place Anything on Top of the Instrument

Never stack instruments or place any other objects on top of the instrument,

especially those containing water. Doing so can lead to malfunction.

• Take Proper Care When Carrying the Instrument

The instrument should always be carried by two people. Hold the instrument by the

handles on the sides of the case. The instrument weighs approximately 19 kg. Take
precautions against injuries when carrying it.

Also, always turn the power switch
OFF, remove the power cable, and confirm that no other cables are connected
before carrying the instrument.

• Clean the Instrument Properly

When removing dirt from the case or operation panel, disconnect the power to the

circuits under test and the instrument, remove the instrument’s power cord from the
power outlet, then wipe gently with a clean, dry cloth. Do not use volatile chemicals
since this might cause discoloring and deformation.

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3

3.2 Attaching the Connector Adapter

Attach the optional connector adapter before using the instrument.

WARNING

Always turn the power OFF before replacing the connector adapter. The instrument
has a built-in reference light source for wavelength calibration, and infrared light is
always being output from the optical output connector. Never look into the optical
output connector. Infrared light entering the eyes can cause severe injury and loss
of vision.

Note

A different connector adapter is used for OPTICAL INPUT and CALIBRATION OUTPUT. Make
sure not to use the wrong connector adapter.

Attachment Procedure

1.

Confirm that the power is OFF.

2.

Open the optical connector cover at the front of the instrument.

3.

Clean the ferrule edge of the optical I/O section using a swab soaked with a small

amount of pure alcohol.

4.

Insert the connector adapter all the way in.

5.

Push the connector adapter’s lock lever down.

The adapter has been attached correctly if the groove in the lock lever interlocks with the
latch pin of the optical input/output section.

Removal Procedure

1.

Confirm that the power is OFF.

2.

Turn the connector adapter’s lock lever up. The lock lever’s lock is released.

3.

Pull the connector adapter all the way out.

4.

Close the optical connector cover at the front of the instrument.

Panel

Lock lever

Ferrule

Latch pin

Optical input
section

Connector
adapter

Attached

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CAUTION

• As there may be dust adhering to calibration output, be sure to clean it before
attaching the connector adapter.

• Do not exhale or blow compressed air into the monochromator from the optical
input. Doing so may allow dust or other materials to enter the monochromator,
adversely affecting its optical performance. Also, if debris is adhering to the
optical components inside the monochromator when a strong light source is
input, the monochromator may be damaged.

• When attaching or removing the connector adapter, carefully insert it
perpendicularly to the ferrule so as not to damage the ferrule end.

• Moving the connector adapter to the right or left or inserting it forcefully can
damage the ferrule or the connector adapter.

Explanation

Types of Connector Adapter

The connector adapter for internal reference light output (AQ9441) comes in the following
three types.

FC type

SC type

ST type

The optical input connector adapter (AQ9447) comes in the following three types.

SC type

ST type

FC type

Optical Connectors Types

The instrument can use FC, SC, or ST type optical connectors.

FC type optical
connector

Cap

SC type optical
connector

Cap

3.2 Attaching the Connector Adapter

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3.3 Connecting a Communication Interface

Connecting the Mouse

You can use a USB or PS/2 mouse.

Supported USB Mouse

The instrument can support a USB HID Class Ver. 1.1 compliant mouse (with wheel).

Connections

The USB mouse is connected to the USB interface on the front panel of the instrument.

1.

Confirm that MAIN POWER switch on the rear panel is OFF.

2.

Orient the USB mouse connector in the proper direction so that it is perpendicular

to the USB port on the front panel, and insert it into the port.

Note

• There are two USB ports, but do not connect a mouse to each port at the same time.

• In addition to a mouse, you can connect a USB storage device.

Supported PS/2 Mouse

The PS/2 wheel mouse by Microsoft® Corporation is recommended for this instrument.

Connections

The PS/2 mouse is connected to the KBD interface (PS/2 terminal) on the rear panel of
the instrument through the keyboard.

1.

Confirm that the MAIN POWER switch on the rear panel is OFF.

2.

Orient the keyboard with the PS/2 mouse terminal to match the direction of the

connector, then connect to the KBD interface on the rear panel.

3.

Connect the PS/2 mouse to the PS/2 terminal on the keyboard.

Note

The default for the PS/2 terminal is the keyboard. To attach a PS/2 mouse directly without going
through the keyboard requires a splitter cable.

For instructions on using the mouse, see section 4.2.

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Connecting a Keyboard

You can connect a keyboard for entering file names, comments, and other items. Also,
the functions and settings of the instrument are assigned to keyboard keys, allowing you
to manipulate them with a keyboard just as you would by using the instrument’s panel
keys.

Supported Keyboards

The instrument supports any 101 English keyboard.

Connections

Connect the keyboard to the KBD connector (PS/2 terminal) on the rear panel of the
instrument.

1.

Confirm that the MAIN POWER switch on the rear panel is OFF.

2.

Orient the PS/2 keyboard to match the direction of the connector, then connect to

the KBD connector on the rear panel.

TRIGGERINTRIGGER

OUT

ANALOG

OUT

SERIAL

(

RS-232

)

ETHERNET

10/100BASE-TX

VIDEO OUT

(
SVGA

)

KBD

GP-IB1

(
IEEE488.1/488.2

)

GP-IB2

(
IEEE488.1

)

(

FOR TLS,ETC.

)

WARNING

Do no t op era te wi th ou t r ea din g th e
safet y pr eca ut ion s in th e use r’ s man ua l.

KBD connector

For information on operations using the keyboard, see section 4.2.

3.3 Connecting a Communication Interface

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3.3 Connecting a Communication Interface

Connecting a USB Storage Device

Supported USB Storage Devices

The instrument supports USB memory (USB card adapters).
You cannot use a USB storage device not recognized by the instrument. If the USB
storage device’s drive is partitioned, only the primary partition (F:) is recognized. If there
are two or more USB storage devices, only the first connected device is recognized.

Connections

Connect the USB storage device to the USB connector on the front panel of the
instrument.

USB

POWER

USB connector

Removing

See section 8.1. (Using the REMOVE USB STORAGE soft key.)

CAUTION

Do not remove the USB storage device or turn the power OFF while the USB
storage device access indicator is blinking. This can damage the data on the device
or the device itself.

Connecting with Other Devices

You can use the GP-IB, RS-232C, or Ethernet interface to connect other external
instruments to the AQ. For details, see the user’s manual of the relevant instrument.

Note

When connecting a GP-IB instrument such as an external computer, or a CRT or other display
to the instrument, always turn OFF the power to the instrument and the instruments to be
connected first. Leaving the power ON while making connections can damage the equipment.

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3.4 Turning the Power ON/OFF

Before Connecting the Power

Take the following precautions before turning on the power supply. Failure to do so can
result in electric shock or damage to instruments.

WARNING

• Before connecting the power cord, ensure that the power supply source voltage
matches the rated supply voltage of the instrument and that it is within the
maximum rated voltage of the provided power cord.

• Check that the instrument’s power switch is OFF before connecting the power
cord.

• To prevent the possibility of electric shock or fire, always be sure to use the
power cord supplied for the instrument by YOKOGAWA.

• Make sure to implement protective earth grounding to prevent electric shock.
Connect the instrument’s power cord into a three-prong electrical outlet with a
protective grounding terminal. The AC outlet must be of a three-prong type with
a protective earth ground terminal.

• Do not use an extension cord without protective earth ground. Otherwise, the
protection function will be compromised.

• Use an outlet that is compatible with the accessory power cord, and be sure to
connect protective grounding. Do not use the instrument if the power outlet does
not provide appropriate protective grounding.

Preparing to Turn ON the Power

The AQ6370B has a MAIN POWER switch for turning the main power ON/OFF, and a
POWER switch for starting and shutting down the instrument. The POWER switch is a

push-button switch; press once to turn it ON and press again to turn it OFF.

•

Confirm that the MAIN POWER switch on the rear panel of the instrument is OFF.

•

Make sure the voltage of the power outlet matches the instrument’s supply

voltage.

•

Before replacing a fuse, always turn the MAIN POWER switch OFF and remove

the power cord from the power outlet.

CAUTION

Do not input a strong light source to the instrument when turning the power ON. If a
strong light source is input, the optical section can be damaged.

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Power On and Screen Display

1.

Connect the power cord to the power cord connector on the back side of the

instrument.

OFF

MAIN POWER

ON

100

­240V

AC

150VA

MAX

50/60Hz

FUSE

250V

T

5A

3-prong outlet

Power cord
(accessory)

3-2 prong adapter
(Japan only)

Protective
grounding
terminal

2.

Turn ON the MAIN POWER switch on the rear panel of the instrument. The

POWER switch on the front panel of the instrument lights orange.

OFF

MAIN POWER

ON

100

-
240V

AC

150VA

MAX

50/60Hz

FUSE

250V

T

5A

3.

Press the POWER switch on the front panel of the instrument. The color of

the switch turns from orange to green. The operating system starts up, and
initialization of the instrument begins.

USB

POWER

The initialization screen appears, and the internal initialization process starts. STEP

1/9 through STEP 9/9 are displayed in the lower right part of the screen to indicate
the progress of initialization.

CAUTION

Do not press the POWER or MAIN POWER switches while initialization is in
progress.
Doing so can cause malfunction.

3.4 Turning the Power ON/OFF

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If initialization finishes successfully, a message appears prompting you to execute
wavelength calibration and alignment adjustment.

The contents of the message are as follows.

For this instrument to meet its specification, a Wavelength Calibration and an

Optical Alignment Adjustment must be performed. Please perform these operations
according to the guidelines below.

Wavelength

Calibration

Perform wavelength calibration before starting measurement (a warm-up of one

hour is also required prior to measurement). Unless the Wavelength Calibration
is carried out, the wavelength accuracy of the instrument cannot be guaranteed.

Alignment Adjustment

Always perform alignment adjustment the first time you use the instrument, if

the instrument was vibrated when being moved, or if the temperature in the
operating environment has changed. Perform the alignment adjustment after
a one-hour warm-up. See section 3.6 for details on the alignment adjustment
operation, and 3.7 for wavelength calibration.

Note

• The instrument “remembers” measurement conditions, selected soft keys, waveforms being
displayed, and other information. When the power is turned ON, the state of the instrument
prior to the last shut down is restored. When the power is turned ON for the first time, the
instrument starts up in the factory default state.

• If an abnormality occurs in memory or another part of the instrument part way through the
initialization process, “STEP @/9” is displayed and the process stops (where @ is a number
from 1 to 9). If this happens, the instrument requires servicing. Please contact your nearest
dealership or sales representative immediately.

Explanation

Screen when the instrument was not shut down

If the shutdown procedure was not performed after the previous session, the following
message appears after start up.
Failure to properly shut down the instrument can result in damage to the monochromator.
When turning OFF the power, always perform the shut down procedure.
Press any key to clear this message.

3.4 Turning the Power ON/OFF

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Turning the Power OFF

1.

Press the POWER switch on the front panel of the instrument. A shut down

confirmation message is displayed along with the YES and NO soft keys.

2.

Press the YES soft key. The message, “AQ6370B is shutting down. Please wait...”

appears, and shut-down begins. If you do not wish to shut down, press the NO
soft key. The screen returns to the original soft key menu.

3.

After the POWER switch changes from green to orange, turn OFF the MAIN

POWER switch on the rear panel of the instrument.

CAUTION

Do not cut the power to the instrument with the MAIN POWER switch on the rear
panel when an operation is in progress. The operating system configuration file will
not be backed up, possibly resulting in malfunctions upon start up the next time the
instrument is turned ON. Always use the above procedure to shut down.

You can also shut down the instrument using panel keys and soft keys.

1.

Press SYSTEM.

2.

Press the MORE soft key three times. The SYSTEM 4/4 screen is displayed.

3.

Press the SHUT DOWN soft key.

4.

Press the YES soft key. Shut down begins.

5.

After the POWER switch changes from green to orange, turn OFF the MAIN

POWER switch on the rear panel of the instrument.

Note

If for some reason the instrument fails to shut down normally, hold down the

POWER

switch
for approximately four seconds or longer to force standby mode. Note that the operating system
configuration file will not be backed up, possibly resulting in malfunctions upon start up the next
time the instrument is turned on.

3.4 Turning the Power ON/OFF

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3.5 Connecting the DUT

Procedure

Connecting Optical Fibers

1.

Clean the tip of the optical fiber with a fiber cleaner.

2.

Open the instrument’s optical input connector cover.

3.

Connect the optical fiber’s optical connector to the optical input connector on the

instrument.

CAUTION

• Before connecting an optical fiber to the instrument, make sure that the start-up
initialization process has finished. If a strong light source is input during start-up,
the optical section can be damaged.

• Be sure to clean the tip of the optical fiber’s optical connector before connecting.

• Do not try to forcefully attach the optical fiber’s optical connector with the plug
inserted at a slanted angle. Doing so may damage the instrument’s optical
connector’s components or the connector itself.

• Before connecting the input light, make sure that it does not exceed the

AQ6370B’s maximum rated level. If input light exceeding the maximum rated

level is introduced, the optical section may be damaged.

• Slanted (angled) PC-type optical connectors cannot be used with the instrument.
Forcefully connecting a slanted (angled) PC-type optical connector may damage
the equipment. Always use optical fibers with a physical contact (PC) type
optical connector.

• Press the optical connector hard against the cleaning surface of the special
cleaner to clean it. If it is not pressed hard against the cleaning surface, it may
not be possible to properly clean the optical connector.

Connecting the DUT (Light Source)

4.

Clean the top of the optical connector on the other end of the optical fiber with a

fiber cleaner.

5.

Connect the optical connector on the other end of the optical fiber to the optical

connector on the DUT.

Measuring System

AQ6370B

Light source

Optical fiber

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3.6 Alignment Adjustment

WARNING

The instrument has a built-in reference light source for wavelength calibration, and
infrared light is always being output from the optical output connector. Never look
into the optical output connector. Infrared light entering the eyes can cause severe
injury and loss of vision.

Procedure

1.

Turn the power to the instrument ON. Turn ON the MAIN POWER switch and

press the POWER switch. For instructions on turning the power ON and OFF, see
section 3.4.

2.

Use a 9.5/125 µm SM optical fiber to connect the instrument’s optical input

connector with the optical output connector.

SM optical fiber
(9.5/125 µm)

AQ6370B

3.

Press SYSTEM. The soft key menu is displayed.

4.

Press the OPTICAL ALIGNMENT soft key.

5.

Press the EXECUTE soft key. Alignment adjustment is automatically executed.

Adjustment finishes a few minutes thereafter, and you are returned to the original
screen.

6.

Press the CANCEL soft key to cancel alignment adjustment partway through the

process.

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Note

• Always use the reference light source built in to the instrument for alignment adjustments.
Alignment adjustments will be incorrect if an external light source is used.

• After alignment has been executed, wavelength calibration is also performed automatically
inside the instrument.

• The alignment adjustment has no effect if the process is stopped. The instrument remains in
the state prior to execution of the alignment adjustment.

Explanation

Types of Optical Fibers

Theinstrumentcanusesinglemodeopticalfiberswithcorediametersof5to9.5μm,
andmultimode(GI)opticalfiberswithcorediametersof50and62.5μm.Functionsmay

be limited or restricted depending on which type of optical fiber is used. The table below
shows which of the typical types of fiber may be used and the limitations on their use.

Limitations on Wavelength Resolution

The maximum wavelength resolution for the instrument is 0.020 nm, which is only
obtainable when using a single-mode optical fiber with a core diameter of 9.5 μm or less.
As shown in Table, the maximum wavelength resolution decreases when optical fibers
with thicker core diameters are used.
Setting a resolution value finer than those shown in the table below will simply result in
an inaccurate measurement level without improving resolution.
Optical fibers with a thick core diameter are especially useful for inputting spatial light for
measurement, but they have poor resolution.
Choose the best type of optical fiber for your particular application.

Note that the instrument is designed for input through optical fiber only. It will not work
with inputs that do not pass through optical fiber, such as direct input of a gas laser
beam to the optical input connector, or bonding an LED to the optical input connector. It
is important to note that optical spectrum measurements taken through such inputs are
completely unreliable.
For spatial light measurements, input the spatial light to the optical fiber and from the
optical fiber to the instrument. A variety of adapters are available for this purpose.

Summary of usable optical fiber types and usage limitations

Optical Fiber Type Obtained Wavelength Absolute Level
Resolution (in nm) Accuracy
Type Core Diameter

SM 5 0.020 NG
SM 9.5 0.020 OK
GI 50 0.050 NG
GI 62.5 0.050 NG
SI 50 0.050 NG
SI 80 0.100 NG
SI 100 0.200 NG
SI 200 0.500 NG
SI 400 1.000 NG
SI 800 2.000 NG

Level Accuracy below the Cutoff Wavelength (Short Wavelength) of a

Connected Optical Fiber

With wavelengths at or below the cutoff level of the connected fiber, light propagates
through the optical fiber in multiple modes. When high-coherent light from a light source
such as a gas laser or DFB-LD light source propagates in multiple modes, speckle noise
contained in the optical fiber output light may become unstable by the optical fiber’s form,
resulting in an inaccurate measurement level.
In such cases, improving the coupling between the light source and the optical fiber will
lessen the level inaccuracy.

3.6 Alignment Adjustment

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3.7 Wavelength Calibration

WARNING

The instrument has a built-in reference light source for wavelength calibration, and
infrared light is always being output from the optical output connector. Never look
into the optical output connector. Infrared light entering the eyes can cause severe
injury and loss of vision.

Procedure

Wavelength Calibration Using the Internal Reference Light Source

1.

Turn the power to the instrument ON.

Turn ON the MAIN POWER switch and press the POWER switch.

For instructions on turning the power ON and OFF, see section 3.4.

2.

Use a 9.5/125 µm SM optical fiber to connect the instrument’s optical input

connector with the optical output connector.

3.

Press the SYSTEM key. The soft key menu is displayed.

4.

Press the WL CALIBRATION soft key.

5.

Press the BUILT-IN SOURCE soft key.

6.

Press the EXECUTE soft key. Wavelength calibration is executed. The previous

screen is displayed again after the calibration process ends.

7.

Press the CANCEL soft key during wavelength calibration to cancel the

wavelength calibration process.

Note

• Always perform wavelength calibration after turning ON the power to the instrument and
allowing the warm-up to finish.

• If you are using this instrument for the first time or using it after it has been severely shaken
while being moved, you must perform the alignment adjustment procedure after warm-up
ends.

• If the wavelength error of the instrument is outside of ±5 nm, you cannot perform wavelength
calibration with the internal reference light source.

(Readjustment required. Contact your nearest Yokogawa representative.)

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Wavelength Calibration Using and External Light Source

Instead of using the internal reference light source, it is also possible to calibrate the
instrument using an external light source. However, the following light sources cannot be
used for wavelength calibration.

• If the set wavelength is not the same as that of the calibration light source.

• If the wavelength error of the instrument is outside of ±0.5 nm.
(Readjustment required. Please contact your nearest Yokogawa representative.)

• If you are using a reference light source with multiple absorption lines, and
the instrument’s wavelength shift is greater than the wavelength interval of the
absorption lines (with the result that an adjacent absorption line is used as the
reference wavelength).

Connecting the External Light Source

1.

Turn the power to the instrument ON.

Press the MAIN POWER switch and press the POWER switch.

For instructions on turning the power ON and OFF, see section 3.4.

2.

Use a 9.5/125 µm SM optical fiber to connect the external light source’s optical

output connector with the optical input connector.

Light source

Optical fiber

AQ6370B

Setting the Type of External Light Source and Calibration Wavelength Value

3.

Press SYSTEM. The soft key menu is displayed.

4.

Press the WL CALIBRATION soft key.

Select the type of external light source (laser-type external light source or gas cell
absorption line type external light source) and set the calibration wavelength value.
There are three different ways to set the wavelength value.

3.7 Wavelength Calibration

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For Laser Type Light Sources

5.

Press the EXECUTE LASER soft key. A screen for specifying the wavelength of

the external light source is displayed.

6.

Select the laser wavelength value using the rotary knob or the arrow keys. The

allowed wavelength range is 600–1700 nm.

7.

Press nm/ENTER. The wavelength value is set.

8.

Press the EXECUTE soft key. Wavelength calibration is executed. The previous

screen is displayed again after the calibration process ends.

9.

Press the CANCEL soft key during wavelength calibration to cancel the

wavelength calibration process.

For Gas Cell Absorption Line Type Light Sources

5.

Press the EXECUTE GAS CELL soft key. A screen for specifying the wavelength

of the external light source is displayed.

6.

Select the gas cell absorption line wavelength value using the rotary knob or the

arrow keys. The allowed wavelength range is 600–1700 nm.

7.

Press nm/ENTER. The wavelength value is set.

8.

Press the EXECUTE soft key. Wavelength calibration is executed. The previous

screen is displayed again after the calibration process ends.

9.

Press the CANCEL soft key during wavelength calibration to cancel the

wavelength calibration process.

3.7 Wavelength Calibration

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Using the Instrument’s Internal Calibration Wavelength Value

6.

Press the CALIB WL SELECT soft key. The soft key menu changes to show

wavelength values.

7.

Press the soft key corresponding to the appropriate wavelength value.

8.

Press the EXECUTE soft key. Wavelength calibration is executed. The previous

screen is displayed again after the calibration process ends.

9.

Press the CANCEL soft key during wavelength calibration to cancel the

wavelength calibration process.

Note

It is not necessary to perform calibration on multiple wavelengths. If calibration is performed on
multiple wavelengths, only the results from the final calibration are applied.

3.7 Wavelength Calibration

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Calibration Table

Editing the User Calibration table. (Wavelength)

1.

Press SYSTEM.

2.

Press the WL OFFSET TABLE soft key. The wavelength calibration table appears

along with a soft key menu for editing calibration values.

3.

Press arrow soft keys to move the cursor to the wavelength to be edited, then

press the WL EDIT soft key. A screen for entering numerical values is displayed.

4.

Enter a value using the rotary knob, arrow keys, or numeric keypad.

5.

Press ENTER.

Note

Normally, it is not necessary to use this function.

Editing the User Calibration table. (Level)

1.

Press SYSTEM.

2.

Press the LVL OFFSET TABLE soft key. The level calibration table appears along

with a soft key menu for editing calibration values.

3.

Press arrow soft keys to move the cursor to the wavelength to be edited, then

press the LEVEL EDIT soft key. A screen for entering numerical values is
displayed.

4.

Enter a value using the rotary knob, arrow keys, or numeric keypad.

5.

Press ENTER.

Note

Normally, it is not necessary to use this function.

3.7 Wavelength Calibration

3-20

IM 735302-01E

3.8 Important Points During Measurement

Types of Optical Fibers

Theinstrumentcanusesinglemodeopticalfiberswithcorediametersof5to9.5μm,
andmultimode(GI)opticalfiberswithcorediametersof50and62.5μm.Functionsmay

be limited or restricted depending on which type of optical fiber is used. The table below
shows which of the typical types of fiber may be used and the limitations on their use.

Limitations on Wavelength Resolution

The maximum wavelength resolution for the instrument is 0.020 nm, which is only

obtainablewhenusingasingle-modeopticalfiberwithacorediameterof9.5μmorless.

As shown in Table, the maximum wavelength resolution decreases when optical fibers
with thicker core diameters are used.
Setting a resolution value finer than those shown in the table below will simply result in
an inaccurate measurement level without improving resolution.
Optical fibers with a thick core diameter are especially useful for inputting spatial light for
measurement, but they have poor resolution.
Choose the best type of optical fiber for your particular application.

Note that the instrument is designed for input through optical fiber only. It will not work
with inputs that do not pass through optical fiber, such as direct input of a gas laser
beam to the optical input connector, or bonding an LED to the optical input connector. It
is important to note that optical spectrum measurements taken through such inputs are
completely unreliable.
For spatial light measurements, input the spatial light to the optical fiber and from the
optical fiber to the instrument. A variety of adapters are available for this purpose.

Summary of usable optical fiber types and usage limitations

Optical Fiber Type Obtained Wavelength Absolute Level
Resolution (in nm) Accuracy
Type Core Diameter

SM 5 0.020 NG
SM 9.5 0.020 OK
GI 50 0.050 NG
GI 62.5 0.050 NG
SI 50 0.050 NG
SI 80 0.100 NG
SI 100 0.200 NG
SI 200 0.500 NG
SI 400 1.000 NG
SI 800 2.000 NG

3-21

IM 735302-01E

Preparing for Measurement

1

2

3

Input Optical Fiber Numerical Aperture (NA) and Level Measurement Values

The level measurement error of the instrument changes as shown in the figure below,
according to the numerical aperture (NA) of the optical fiber connected to the input

connector.Theinstrument’sabsoluteleveliscalibratedusinga9.5/125μmsingle-mode
opticalfiber(SSMAtypeinJISC6835,withPCpolishing,9.5μmmodefielddiameter,

and 0.104 to 0.107 NA). Even if a single-mode optical fiber is used, the level accuracy
will be outside the specifications if the NA is not in the range shown above.

Input optical fiber numerical aperture and level error (typical characteristics)

-0.50

-0.40

-0.30

-0.20

-0.10

0.00

0.10

0.20

0.30

0.40

0.101 0.102 0.103 0.104 0.105 0.106 0.107 0.108 0.109 0.110

0.50

Level error (dB)

Numerical Aperture

Absolute Level Accuracy

Theinstrument’sabsoluteleveliscalibratedwitha9.5μmsingle-modeopticalfiber.

In terms of actual capability, even single-mode optical fibers that do not have a core

diameterof9.5μmprovidenearlythesamelevelofaccuracy.

Multimode (GI) fiber provides a relatively accurate spectrum if the light source is low­coherent light such as white light, natural light, or an LED. If the light source has high
coherency as in the case of a laser beam, interference will occur inside the optical fiber,
and the intensity distribution of light radiating from the fiber tip will vary according to the
fiber form. As a result, the spectrum (measurement level) may fluctuate if the fiber is
moved.
When an optical fiber with a large core diameter or large NA value is used, a low fraction
of the light emitted from the optical fiber is received. Therefore, the measurement level is
lower than the true value, but the optical spectrum is accurate in relative terms.

Level Accuracy below the Cutoff Wavelength (Short Wavelength) of a

Connected Optical Fiber

With wavelengths at or below the cutoff level of the connected fiber, light propagates
through the optical fiber in multiple modes. When high-coherent light from a light source
such as a gas laser or DFB-LD light source propagates in multiple modes, speckle noise
contained in the optical fiber output light may become unstable by the optical fiber’s form,
resulting in an inaccurate measurement level.
In such cases, improving the coupling between the light source and the optical fiber will
lessen the level inaccuracy.

3.8 Important Points During Measurement

3-22

IM 735302-01E

Measurement Sensitivity and Vertical Axis Effective Range

When the measurement sensitivity is set to NORMAL HOLD, the internal amplifier has
a fixed gain. Five different gains are set automatically according to the reference (REF)
level setting. However, the effective range of measurement data is limited to the following
range, using the reference (REF) level (dBm) as a reference.

REF-20 dBm < (effective range) < REF+10 dBm

If the level scale is set to 10 dB/DIV, the display would exceed the effective range, so the
areas at 10 dB from the screen stop and 20 dB from the bottom are inaccurate.
When measurement sensitivity is set to NORMAL HOLD, we recommend setting the
level scale to 5 dB/DIV or less.
Under the measurement sensitivity settings NORMAL AUTO, MID, and HIGH 1–3, an
automatic gain is used, permitting measurements over a wide level range through a
single sweep. Select the appropriate sensitivity level based on the light reception level
required for the particular measurement application.

Stray Light from the Monochromator

The instrument has a newly designed, high-performance monochromator. Depending
on the measurement conditions, stray light at a level 30 to 50 dB below the original
spectrum, as well as other stray light specific to the monochromator may occur in
wavelength areas 100 to 200 nm from the peak wavelength. If this stray light is likely
to have a severe impact on measurements, the sensitivity can be set to HIGH 1–3 and
CHOP MODE can be set to CHOP or SWITCH in order to reduce the effects of the stray
light.

Waveform with CHOP MODE OFF CHOP MODE set to SWITCH

CHOP MODE Function List

CHOP

MODE

Function Merit Defect

OFF

Measurement according to the
stray light.

Stray light suppression ratio:
40 dB or more

Measurement time is rapid
even for high sensitivity
measurements.

Since the stray light is also
measured, the low level
component is not accurate
if the light source is of high
power.

SWITCH

Two sweeps per measurement

areperformed.Therstsweep

measures the stray light
component, and high dynamic
measurement is possible
through subtraction.
Stray light suppression ratio:
60 dB or more

Short-duration
measurement can be taken
with stray light removed.

If the measurement duration

islong,itisinuencedby

temporal changes in the
measured light.

3.8 Important Points During Measurement

3-23

IM 735302-01E

Preparing for Measurement

1

2

3

Ripples in the 1350–1450 nm Area

Water (OH-) ions present in the monochromator absorb light in the 1350–1450 nm area,
resulting in ripples in the measurement waveform. Either set a coarser resolution or use
the monochromator in a lower-humidity environment to reduce the amount of ripples.

Waveforms with Resolutions of 0.020 nm

When the resolution is set to 0.020 nm for measurements of a light source such as a
DFB laser in which with the spectral width is narrower than the instrument’s resolution,
very small spikes may occur at the skirts of the waveform. This type of spike occurs due
to characteristics of the optical block and is not an indication of any problem. Even if such
spikes occur, satisfactory performance in terms of resolution, dynamic range, and the like
can be ensured. These spikes will disappear if the resolution is set to a coarser value.

Second-Order Diffracted Light

The monochromator in this instrument uses a diffraction grating, and when light in a
certain wavelength range is input, a “grating ghost” of second-order diffracted light
appears.
Therefore, it is important to understand this distinctive characteristic in order to correctly
analyze the measured results from the instrument.
The graph below shows the correlation between the wavelength displayed on screen and
the actual wavelength.
The displayed wavelength is on the horizontal axis, with the true wavelength on the
vertical axis. The solid lines in the graph indicate correspondences between displayed
and actual wavelengths. The thick solid line is the correlation with the correct light
spectrum (of course, the displayed wavelength and actual wavelength match), and
the thin solid line shows the correlation with the ghost spectrum of the second-order
diffracted light.
For example, if 633 nm light is input, a horizontal line is drawn at 633 nm on the vertical
axis, and the point of intersection on the graph of the line is the displayed wavelength.
From this, you can see that besides 633 nm, a grating ghost appears at 1266 nm.

3.8 Important Points During Measurement

3-24

IM 735302-01E

3.8 Important Points During Measurement

Relationship between the Wavelength Displayed on Screen and the Actual Wavelength

500

600

700

800

900

1000

1100

1200

1300

1400

1500

1600

1700

1800

500 600 700 800 900 1000 1100 1200 1300 1400 1500 1600 1700 1800

Actual wavelength (nm)

Wavelength displayed on screen (nm)

Second-order diffracted light

1266nm

ex. 633nm

Example of measurement in which second-order diffracted light appears at 1266 nm

The ghost spectrum of the second-order

diffracted light

4-1

IM 735302-01E

Common Operations

1

2

3

4

4.1 Description of Soft Keys

When you press a function key, the soft key menu (inside the screen) located on the right
side of the screen changes.
The soft key menus are designed to provide a certain level intuitiveness, with the
individual soft keys having particular forms which make them easy to understand.

Forms and Behavior

This is a normal soft key.
Press to execute its function immediately.

Contains a submenu.
Indicates that there is a submenu of additional items related to
the current item.
Press to display the submenu.

A separate window will be displayed.
Press to display a separate window in the screen for entry of
numerical parameters.
A submenu and separate window will be displayed.

Press to move to the submenu and display a separate window.
This softkey returns to the previous menu.

Press to display the previous soft key menu.
This is a selection soft key.

Select one of the soft keys connected with the black band.
When selected, the soft key is displayed in reverse video.
Several soft keys can be connected.

Chapter 4 Common Operations

4-2

IM 735302-01E

Display Examples

LEVEL

MORE 1 / 2

LEVEL

RETURN
LEVEL

MORE 2 / 2
Y SCALE
SETTING

REF LEVEL

***.*dBm

LEVEL UNIT

dBm dBm/nm

LIN SCALE

PEAK
→REF LEVEL

LIN
BASE LEVEL

**.*mW

Y SCALE
SETTING

Y SCALE
DIVISION

8 / 10 / 12

LOG SCALE

**.*dB/D

AUTO
REF LEVEL

OFF / ON

SUB REF LVL
POSITION

**DIV

AUTO
SUB SCALE

OFF / ON

LENGTH

**.***km

SCALE MIN

**.*%

SUB SCALE

**.*%/D

SUB SCALE

**.*dB/km

SUB LIN

*.***/D

**.*dB/D

REF LEVEL
POSITION

**DIV

LEVEL 1/2

LEVEL 2/2

The LEVEL soft key menu is split into two parts.
This key switches between the menus.
In addition, in some cases this may change
to a function that closes the window. For example,
when the MORE 1/2 soft key is pressed, the
menu changes to the LEVEL 2/2 soft key menu,
and the key display changes to MORE 2/2.

Shows the submenu of the soft key menu.
In this example, the soft key menu is within
the Y SCALE SETTING submenu
(for display only, no keys are available).

4.1 Description of Soft Keys

4-3

IM 735302-01E

Common Operations

1

2

3

4

4.2 Using the Mouse and External Keyboard

Using the Mouse

With a connected mouse you can perform the same operations as with the instrument's
panel keys. Also, if you move the mouse pointer over the item in the menu screen that
you wish to select and click it, the instrument responds exactly as if you had pressed the
corresponding soft key. The USB mouse is connected to the USB interface on the front
panel of the instrument.
For instructions on connecting the mouse, see section 3.3.

Operations the Same as the Panel Keys

Displaying the Top Menu

Right-click the mouse in the screen. The names of the front panel keys in the instrument's
FUNCTION section are displayed.

CENTER
SPAN
LEVEL
SWEEP
ZOOM
SETUP
TRACE
DISPLAY
MARKER
PEAK SEARCH
ANALYSIS
USER
MEMORY
FILE
PROGRAM
ADVANCE
SYSTEM
UNDO/LOCAL
COPY
FEED
HELP

Selecting Items

Move the pointer to the item you wish to select and click. A setting menu for the selected
item appears. The list of front panel key names disappears.

Clearing the List of Front Panel Keys

Move the pointer away from the list of front panel keys and click.

Operations the Same as the Soft Keys

Selecting Functions from the Soft Key Menu

Move the pointer to the soft key you wish to select and click. A screen corresponding to
the action of the soft key appears.

4-4

IM 735302-01E

4.2 Using the Mouse and External Keyboard

Using the External Keyboard

The functions of each of the front panel keys of the instrument are assigned to keyboard
keys, allowing you to manipulate them with a keyboard just as you would by using the
instrument's panel keys.
The panel key correspondence table below shows the correspondences between the
panel keys and the keys on the keyboard. Also, you can directly enter labels, file names,
and numbers.

Panel Key Correspondence Table

Type Function External

Keyboard

Description

FUNCTION

Sweep SWEEP [SHIFT]+[F1] Executes/sets sweep

Meas.
settings

CENTER [SHIFT]+[F2] Sets measurement center

wavelength
SPAN [SHIFT]+[F3] Sets measurement span
LEVEL [SHIFT]+[F4] Sets level axis
SETUP [SHIFT]+[F5] Sets resolution, sensitivity, etc.

Display
settings

TRACE [SHIFT]+[F6] Sets trace
ZOOM [SHIFT]+[F7] Sets display scale
DISPLAY [SHIFT]+[F8] Sets screen display

Analysis
functions

MARKER [SHIFT]+[F9] Sets marker
SEARCH [SHIFT]+[F10] PEAK/BOTTOM search function
ANALYSIS [SHIFT]+[F11] Sets analysis function

Other

USER [ALT]+[F1] User settings menu
MEMORY [ALT]+[F2] Memory
FILE [ALT]+[F3] Saves/opens files, file actions
PROGRAM [ALT]+[F4] Program Functions
ADVANCE [ALT]+[F5] Advanced functions
SYSTEM [ALT]+[F6] System settings

Soft keys F1 to F9 F1 to F9 Depends on FUNCTION menu

Auxiliary keys

UNDO/LOCAL [ALT]+[F9] Local: UNDO function

Remote: Returns to the local

state.
COPY [ALT]+[F10] Screen copy
FEED [ALT]+[F11] Feeds internal printer paper
HELP [ALT]+[F12] Displays Help (use UNDO/

LOCAL to exit Help)

DATA ENTRY

Numeric keypad 0123456789.- Numeric value input
BACK SPACE Back Space Deletes one character from input

value
um/ENTER None Confirms entry
nm/ENTER ENTER Confirms entry
Rotary knob [→],[←] Changes numeric values/items
Arrow keys

([UP][DOWN])

[↑],[↓] Numeric value one-step

change, item change, table

scrolling
COARSE [ALT]+[N] Switches between fine and

coarse encoder

4-5

IM 735302-01E

Common Operations

1

2

3

4

4.3 Entering Numerical Values and Strings

Entering Numerical Values

You can use the numeric keypad, rotary knob, or arrow keys in the DATA ENTRY section.

1.

Press the soft key of a parameter. The currently set value is shown in the

parameter input window.

Direct Entry Using the Numeric Keypad

2.

Press a numeric keypad key. The numeric keypad input area appears, and the

number of the pressed key is displayed.

3.

After entering a numerical value, press the μm/ENTER or nm/ENTER key

depending on the unit of the input parameter. The value in the numeric keypad
input area appears in the parameter input window, and is set internally. If a
parameter does not have a unit associated with it, you can use either the μm/
ENTER or nm/ENTER key.

If you make an error when inputting values with the numeric keypad:

4.

Press BACK SPACE. The last (right-most) entered character in the numeric

keypad input area is removed, allowing entry of the correct character.

Note

• If the value entered with the numeric keypad is not in the allowed value range, the nearest
allowed value will be set.

• By holding the BACK SPACE key down, you can erase the entire entry in the numeric
keypad input area and make the numeric keypad input area disappear, returning to the
condition preceding numeric keypad input.

Entry Using the Rotary Knob and Arrow Keys

2.

Continuing on from step 1, turn the rotary knob, or press an arrow key. The

currently set value is changed.

3.

When you press the COARSE key the digit of the setting to be changed rises,

or the numeric value increase/decrease step increases. Press the COARSE key
again to restore the previous digit/step.

When COARSE is selected, the COARSE key lights.

DATA ENTRY

COARSE

7

8

9

4

5

6

1

2

3

0

.

-

BACK

SPASE

nm/

ENTER

m/

ENTER

Numeric keypad

Arrow keys

Rotary knob

4-6

IM 735302-01E

Entering Strings

Character strings can be entered from the character selection area displayed on screen
using the rotary knob and soft keys.

Entry Procedure

The following is an example of entering a label.

1.

Press DISPLAY. The soft key menu for the screen display appears.

2.

Press the LABEL soft key. The text selection area and label entry area are

displayed.

Move cursor to right

Move cursor to left

Insert character

Delete character

Delete all characters

Enter characters

Manipulate preset word

Finalize entry

Discard changes

3.

Move the cursor to the character in the character selection area that you wish

to enter. Use the rotary knob or arrow keys to move the cursor in the character
selection area.

4.

Press the ENTER soft key. The character selected at the cursor position in the

label input area is displayed.

5.

To move the cursor, or insert or delete a character in the label input area, press

the corresponding soft key.

6.

When the character string is entered, press the DONE soft key. The input

character string is entered.

Note

• In addition to when pressing DISPLAY, the character input screen appears whenever a
string must be entered on the instrument, such as when entering a file name for saving a
file.

• Numerical input can be performed directly from the numeric key pad.

4.3 Entering Numerical Values and Strings

4-7

IM 735302-01E

Common Operations

1

2

3

4

4.4 Screen Display

Procedure

1.

Press SYSTEM. The soft key menu is displayed.

2.

Press the MORE 1/4 soft key two times. The soft key menu switches to the MORE

3/4 screen.

Setting the Number of Displayed Digits for Level Data

3.

Press the LEVEL DISP DIGIT soft key. The digit setting menu is displayed.

4.

Press the soft key corresponding to the desired number of digits.

1DIGIT Sets the number of level data display digits (below the decimal point)
to 1 digits.
2DIGIT Sets the number of level data display digits (below the decimal point)
to 2 digits.
3DIGIT Sets the number of level data display digits (below the decimal point)
to 3 digits.

Transparent

Display

Changing the

Display Colors

Transparent Display

3.

Continuing on from step 2, press the WINDOW TRANSPARENT OFF ON soft

key. Transparent display turns ON or OFF. When ON, the parameter input window
and overview display window are displayed transparently.

Changing the Display Colors

3.

Continuing on from step 2, press the COLOR SELECT soft key. The display color

setting menu is displayed.

4.

Press the soft key corresponding to the desired display color.

COLOR1 Sets the screen display color to “COLOR 1”.
COLOR2 Sets the screen display color to “COLOR 2”.
COLOR3 Sets the screen display color to “COLOR 3”.
COLOR4 Sets the screen display color to “COLOR 4”.
COLOR5 Sets the screen display color to “COLOR 5”.
B&W Sets the screen display color to black-and-white.

4-8

IM 735302-01E

4.5 Setting the Date and Time

The AQ6370B displays the date and time in the upper right corner of the screen. This
information is used when outputting to a printer, or for a time stamp when recording data.

Displaying the Date and Time Dialog Box

1.

Press SYSTEM. The soft key menu is displayed.

2.

Press the MORE soft key two times. The soft key menu switches to the MORE

3/4 screen.

3.

Press the SET CLOCK soft key. The internal clock setting screen is displayed.

Entering the Date and Time

4.

Press the CURSOR -> soft key, then move the cursor to the item you wish to

input. The cursor moves each time you press the soft key.

5.

Press a numeric key button to enter a number.

6.

Press ENTER. The input number is entered.

Changing the Display Format

7.

Press the MO-DY-YR soft key.

The date is displayed in the order Month, Day, Year.

Press the DY-MO-YR

soft key.

The date is displayed in the order Day, Month, Year.

Press the YR-MO-DY

soft key.

The date is displayed in the order Year, Month, Day.

Concluding the Settings

8.

Press the RETURN soft key. The settings are concluded, and the screen returns

to the previous stage.

4-9

IM 735302-01E

Common Operations

1

2

3

4

4.6 Printing Out Using the Internal Printer (Optional)

Printer Roll Paper

The printer uses proprietary roll paper. Do not use any other kind of paper. When using
the printer for the first time, use the paper included. When the roll paper runs out, order
refills from you nearest Yokogawa branch, dealer, or sales office.

Part Number B9988AE
Specifications Thermal sensible paper, 10 m
Lot qty. 10 rolls

Handling the Roll Paper

This roll paper is thermal-sensible roll paper that changes color through a thermochemical
reaction. Therefore, please note the following.

Storage Precautions

Thermal-sensible paper that is being used starts to change color gradually at
70°C. Since it is affected by heat, humidity, light, chemicals, and other factors even when
unused or finished being used, the following precautions must be taken.

• Store the paper in a dry, cool place.

• Use the paper as quickly as possible after opening the package.

• If plastic film containing plasticizers (such as vinyl chloride film or cellophane tape)
are allowed to come into contact with the paper for long periods of time, recorded
items can fade. For example, if storing the printouts in a binder, use one made of
polypropylene.

• If using adhesive on the paper, do not use an adhesive containing alcohol, ethyl, or
other organic compounds. Discoloration can result.

• When storing printouts for long periods of time, it is recommended to make
photocopies. Due to the properties of thermal-sensible paper, recorded portions on
the paper can fade.

Usage Precautions

• Always use the proprietary roll paper supplied by Yokogawa.

• If handled with sweaty hands, fingerprints can appear, or recorded information can
be smeared.

• If you rub the surface with a hard object, heat from the friction can cause marks to
appear.

• If chemicals, oil, or other substances contact the paper, discoloration or erasure of
recorded information can occur.

4-10

IM 735302-01E

Installing Roll Paper

Printer cover

Handle

Lock release
lever

Open the printer cover by lifting it up by the
handle on the left side while pressing the lock
release lever in the OPEN direction.

Release arm

Movable holder

Move the release arm in the right-front to
the MAN FEED position. Orient the roll
paper so that the inner side (not the shiny
side) faces up. Pushing the movable
holder on the left side of the roll paper bin
to the left, place the roll into the bin
right-side-first, then release the movable
holder.

MAN FEED

Turn the feed knob

Roll paper

Release arm

Guide

Roller

Insert the edge of the roll paper evenly
between the roller and black-colored
guide, then turn the paper feed knob until
the edge of the roll paper protrudes about
10 cm from the top of the roller.

FREE

HOLD

Move the release arm to the FREE position,
adjust the slack of the roll paper, then move
the release arm to the HOLD position. If the
arm is left in the FREE or MAN FEED
position, a printer error will occur, and
printing will be disabled.

Fold the printer cover down toward you to
close it. As you close the cover, feed the
paper through the paper ejection hole in the
cover. Close the cover firmly until you hear
a click.

Note

The paper feed can be unstable immediately after the roll paper has been installed. Print out 2
or 3 screen shots before beginning normal use.

4.6 Printing Out Using the Internal Printer (Optional)

4-11

IM 735302-01E

Common Operations

1

2

3

4

Printing

You can output the measured waveforms displayed on screen to the internal printer.

Executing Printing

1.

Press COPY. An image of the current screen is printed on the built-in printer.

Cancelling Printing

2.

Press UNDO/LOCAL.

Feeding Paper

3.

Press FEED. Paper feeding continues as long as you hold down the button.

Note

• If you press COPY during sweeping, sweeping stops. After printing, sweeping starts again.

• If the printer runs out of recording paper during printing or if you press COPY without
returning the release arm to the HOLD position, the following warning is displayed:
(WARNING 160 : “Printer paper empty”, WARNING 161 : “Printer head up”).

• When printing continuously for a long period of time, the printer head can become hot,
causing printer failure. The following warning is displayed: (WARNING 164: “Printer Head
Temperature error”). If this warning appears, wait a few minutes and try again. When the
printer head cools down, the printing capability will be restored. Avoid printing continuously
for long periods of time.

4.6 Printing Out Using the Internal Printer (Optional)

5-1

IM 735302-01E

Mesurement

1

2

3

4

5

5.1 Auto Measurement

Procedure

This key automatically sets the optimal measurement conditions for the light source
being measured, and performs measurement.

1.

Press SWEEP. The soft key menu regarding sweeping appears.

2.

Press the AUTO soft key. The soft key display reverses, and auto measurement

executes.

Waveform display example

Screen after auto sweep stop

Screen after auto sweep start value

Explanation

The wavelength range of input light that can be auto-measured is 1200–1670 nm.
The following four items are set automatically, after which measurement is performed.

• Center wavelength (CENTER)

• Sweep width (SPAN)

• Reference level (REF LEVEL)

• Resolution (RESOLUTION)

After performing one auto sweep and setting optimal measurement conditions, a repeat
sweep is made for measurement.
During the automatic setting, only the following keys are enabled: REPEAT, SINGLE,
STOP, and UNDO/LOCAL (when under remote control).

Chapter 5 Mesurement

5-2

IM 735302-01E

5.2 Horizontal/Vertical Axis Settings

Procedure

Setting Up the Horizontal Axis

The units of the horizontal axis can be set to wavelength or frequency.

1.

Press SETUP. The soft key menu for sweep condition settings appears.

2.

Press the HORIZON SCAL nm/THz soft key. The units for the horizontal axis

switch from THz to nm, or viceversa.

Note

Pressing the HORIZON SCALE nm/THz soft key repeatedly toggles between nm and THz.

Setting the Measured Wavelength to Air Wavelength or Vacuum Wavelength

1.

Press SETUP. The soft key menu for sweep condition settings appears.

2.

Press the MEAS WL AIR VACUUM soft key. The measured wavelength is

changed to either a vacuum wavelength or an air wavelength.

NOTE

• This function only applies to measurements taken after the setting is selected. Previously
measured waveforms are not affected.

• If vacuum wavelength is set, is displayed at the very bottom of the screen in inverse
video.

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Setting Up the Vertical Axis

Setting to Log Scale Display

1.

Press LEVEL. The soft key menu for vertical axis settings appears along with the

reference level setting screen.

2.

Press the LOG SCALE soft key. The vertical axis is displayed with the currently

specified log scale values. At the same time, the log scale value setting screen is
displayed.

3.

Enter a log scale value using the rotary knob, arrow keys, or numeric key pad.

4.

Press ENTER.

Setting to Linear Scale Display

1.

Press LEVEL. The soft key menu for vertical axis settings appears along with the

reference level setting screen.

2.

Press the LIN SCALE soft key. The vertical axis is displayed with the currently

specified linear scale values.

3.

Press the LIN BASE LEVEL soft key. A screen for setting the lower-end value of

the level scale is displayed.

4.

Enter a value using the rotary knob, arrow keys, or numeric key pad.

5.

Press ENTER.

5.2 Horizontal/Vertical Axis Settings

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Setting Units for the Vertical Axis

1.

Press LEVEL.

2.

Press the LEVEL UNIT soft key. When the vertical axis is log scale, the

instruments toggle between dBm and dBm/nm each time you press the key. With

alinearscale,itscrollsthroughnW,μW,mW,orpW,andnW/nm,μW/nm,mW/nm

or pW/nm.

Setting the Number of Vertical Axis Divisions (for LOG SCALE)

1.

Press LEVEL.

2.

Press the LOG SCALE soft key.

3.

Press the Y SCALE SETTING soft key. The level scale setting menu is displayed.

4.

Press the Y SCALE DIVISION soft key. The soft key menu for selecting a number

of divisions is displayed.

5.

Press a soft key corresponding to 8, 10, or 12 divisions. The level axis is

displayed with divisions as selected.

Note

• This is only available when the main scale is a log scale.

• When it is a linear scale, the number of divisions is fixed at 10.

Reference Level Screen Position Setting (for LOG SCALE)

4.

Continuing on from step 3, press the REF LEVEL POSITION soft key. A screen

for setting the screen position of the reference level (REF position) is displayed.

5.

Enter a value starting from the bottom of the screen using the rotary knob, arrow

keys, or numeric key pad. The setting range is 0 to 12. The setting resolution is
steps of 1, or steps of 1-2-5 when COARSE is pressed.

6.

Press ENTER.

Note

• This is only available when the main scale is a log scale.

• If the REF position value is larger than the number of divisions, it is forcibly reduced to the
number of divisions.

• When using linear scale, the REF position is at the top (fixed to 10 divisions).

5.2 Horizontal/Vertical Axis Settings

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Explanation

Wavelength Display Mode

• Displays the measured waveform with the wavelength on the X axis.

• The measurement scale and display scale are set based on the wavelength.

• The X axis unit for marker values and analysis function results is wavelength.

Frequency Display Mode

• Displays the measured waveform with the frequency on the X axis.

• The measurement scale and display scale are set based on the frequency.

• The X axis unit for marker values and analysis function results is frequency.

Display Units of the X-Axis and Marker Values

The display unit for the marker value (wavelength or frequency) can be set independently
of the waveform display’s horizontal axis units (wavelength or frequency) that were
specified using the HORIZON SCALE nm/THz soft key under SETUP. (Default: nm)
(This key can be used to enter settings such as frequency display mode on the X axis
and wavelength display mode for the marker value.)

Also, the MARKER UNIT nm THz soft key’s setting changes in conjunction with the
setting of the HORIZON SCALE soft key. However, changing the MARKER UNIT nm THz
soft key’s setting does not change the setting for the HORIZON SCALE nm/THz soft key.

Note

The MARKER UNIT nm THz soft key’s setting changes in conjunction with the setting of the
HORZN SCALE soft key. However, changing the MARKER UNIT nm THz soft key’s setting
does not change the setting for the HORIZON SCALE nm/THz soft key.

LOG SCALE **.*dB/D

This key switches the vertical axis to LOG display and sets the level scale.
The setting range is 0.1 to 10.0 dB/DIV. Settings can be adjusted in steps of 0.1 dB.
If you press the COARSE key you can change the numerical value in 1-2-5 steps, for
example: 1dB/DIV -> 2dB/DIV -> 5dB/DIV.
When the setting is changed, the displayed waveform is redrawn according to the
changed scale.
If the value is set to a scale larger than 5 dB/DIV in range fixing mode (SENS:NORMAL/
HOLD) or pulse light measurement mode, the waveform will not be correctly measured in
the vertical direction so a warning is displayed.

Measurement Sensitivity and Vertical Axis Effective Range

When the measurement sensitivity is set to NORMAL HOLD, the internal amplifier has
a fixed gain. Five different gains are set automatically according to the reference (REF)
level setting. However, the effective range of measurement data is limited to the following
range, using the reference (REF) level (dBm) as a reference.

REF-20 dBm < (effective range) < REF+10 dBm

If the level scale is set to 10 dB/DIV, the display would exceed the effective range, so the
areas at 10 dB from the screen stop and 20 dB from the bottom are inaccurate.
When measurement sensitivity is set to NORMAL HOLD, we recommend setting the
level scale to 5 dB/DIV or less.
Under the measurement sensitivity settings NORMAL AUTO, MID, and HIGH 1–3, an
automatic gain is used, permitting measurements over a wide level range through a
single sweep. Select the appropriate sensitivity level based on the light reception level
required for the particular measurement application.

5.2 Horizontal/Vertical Axis Settings

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LIN SCALE

This key is used to set the main scale to linear scale.
Settings per 1 DIV are set in the reference level.

LIN BASE LEVEL **.*mW

Value when the vertical axis is linear scale, you can set the level scale low-end. This is
not available when using a log scale.
The setting range is 0.0 to REF level x 0.9. Settings can be adjusted in steps of 0.1. The
value changes in steps of 1 if you press the COARSE key. Values can only be set in the
instrument set for the REF level.
When the setting is changed, the displayed waveform is redrawn according to the
changed scale.
The scale display in the upper left part of the waveform is 1/10 the value (*W/D) of the
reference (REF) level minus the low-end (BASE) level.
For information on the REF level setting, see section 5.4, "Setting the Reference Level."

LEVEL UNIT dBm dBm/nm

When the vertical axis is log scale, the display toggles between dBm and dBm/nm.
dBm: Power per resolution (absolute power)
dBm/nm: Power per 1 nm (power density)
For information on the use of dBm and dBm/nm, see “Power Density Display” in section

2.2, “Measurement.”

LEVEL UNIT mW mW/nm

Whenthelevelaxisusesalinearscale,thedisplayswitchesbetweennW,μW,mW,or
pW(absolutepower),andnW/nm,μW/nm,mW/nmorpW/nm(powerdensity).

5.2 Horizontal/Vertical Axis Settings

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5.3 Sub Scale

Procedure

The level scale is displayed based on relative values when a differential waveform (based
on LOG values) or normalized waveform is displayed. A level scale based on relative
values is called a sub scale.

Displaying the Sub Scale

Following section 6.5, “Displaying MATH Waveforms” or section 6.6, “Normalized
Display,” you can select a display waveform of differential or normalized.

Automatic Scaling of the Sub Scale

1.

Press LEVEL. The soft key menu for vertical axis settings appears.

2.

Press the MORE 1/2 soft key. The soft key menu for the sub scale appears.

3.

Press the AUTO SUB SCALE OFF ON soft key to select ON.

Setting the Sub Scale REF Position

1.

Press LEVEL.

2.

Press the MORE 1/2 soft key.

3.

Press the SUB REF LVL POSITION soft key. The REF position setting screen is

displayed.

4.

Enter a value using the rotary knob, arrow keys, or numeric key pad.

Note

The sub scale is displayed when a differential waveform (based on LOG values) and
normalized waveform are displayed. When these waveforms are displayed over a waveform
based on absolute values, the absolute value scale is shown on the left and the relative value
scale is shown simultaneously on the right. If the left scale (main scale) is changed to LOG (8
DIV) or linear (10 DIV), the sub scale is displayed to correspond to the DIV count on the main
scale.

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Log Display of the Sub Scale

1.

Press LEVEL. The soft key menu for vertical axis settings appears.

2.

Press the MORE 1/2 soft key. The soft key menu for the sub scale appears.

3.

Press the SUB LOG soft key. The sub scale is displayed with the currently

specified log scale values. At the same time, the log scale value setting screen is
displayed.

4.

Enter a value using the rotary knob, arrow keys, or numeric key pad.

5.

Press ENTER.

Setting the Sub Scale Units to dB/km

1.

Press LEVEL.

2.

Press the MORE 1/2 soft key.

3.

Press the SUB SCALE **.*dB/km soft key. The instruments of the sub scale

change to dB/km. At the same time, the log scale value setting screen is
displayed.

4.

Enter a value using the rotary knob, arrow keys, or numeric key pad.

5.

Press ENTER.

When displaying the loss characteristics of the optical fiber per unit of length (km)

6.

Continuing on from step 5, press the LENGTH soft key. The optical fiber length

entry screen appears.

7.

Enter a value using the rotary knob, arrow keys, or numeric key pad.

8.

Press ENTER.

Setting the Sub Scale Offset Value

1.

Press LEVEL.

2.

Press the MORE 1/2 soft key.

3.

Press the OFFSET LEVEL soft key. The offset value (sub scale REF value)

setting screen is displayed.

4.

Enter a value using the rotary knob, arrow keys, or numeric key pad.

5.

Press ENTER.

5.3 Sub Scale

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Setting the Sub Scale to Linear Display

1.

Press LEVEL. The soft key menu for vertical axis settings appears.

2.

Press the MORE 1/2 soft key. The soft key menu for the sub scale appears.

3.

Press the SUB LIN soft key. The sub scale is displayed with the currently specified

linear scale values. At the same time, the linear scale value setting screen is
displayed.

4.

Enter a value using the rotary knob, arrow keys, or numeric key pad.

5.

Press ENTER.

Setting the Sub Scale Units to %/D

1.

Press LEVEL.

2.

Press the MORE 1/2 soft key.

3.

Press the SUB SCALE **.*%/D soft key. The instruments of the sub scale display

change to %. At the same time, the log scale value setting screen is displayed.

4.

Enter a value using the rotary knob, arrow keys, or numeric key pad.

5.

Press ENTER.

Setting the Sub Scale Lower-End Value

1.

Press LEVEL.

2.

Press the MORE 1/2 soft key.

3.

Press the SCALE MIN soft key. The sub scale lower end value setting screen is

displayed.

4.

Enter a value using the rotary knob, arrow keys, or numeric key pad.

5.

Press ENTER.

5.3 Sub Scale

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Explanation

SUB SCALE **.*dB/km

(Setting the sub scale to dB/km)
The setting range is 0.1 to 10.0 dB/km. Settings can be adjusted in steps of 0.1. If you
press the COARSE key you can change the numerical value in 1-2-5 steps, for example:
1dB/DIV -> 2cB/DIV -> 5dB/DIV.
When the setting is changed, the displayed waveform is redrawn according to the
changed scale.

SUB SCALE ***.*%/D

(Sets the sub scale to %.)
The setting range is 0.5 to 125 %/D. Settings can be adjusted in steps of 0.1. The value
changes in steps of 1-2-5 if you press the COARSE key.
When the setting is changed, the displayed waveform is redrawn according to the
changed scale.

OFFSET LEVEL

(Sets the offset value. This is enabled when the sub scale is dB/D or dB/km.
The range that can be set is as follows.)
For dB/D: 0–±99.9 dB. Settings can be adjusted in steps of 0.1. The value changes in
steps of 1 if you press the COARSE key.
For dB/km: 0–± 99.9 dB/km in steps of 0.1.

SCALE MIN

(Sets the scale lower-end value. This is available when the sub scale is LIN or %.
The range that can be set is as follows.)
For LIN: 0 to the sub scale value (***.*/D) x 10
For %: 0 to the sub scale value (***.*%/D) x 10

LENGTH **.***km

(Sets the length of the optical fiber. This is available when the sub scale is dB/km.)
The setting range is 0.001 to 99.999 km. Settings can be adjusted in steps of 0.001. The
value changes in steps of 1-2-5 if you press the COARSE key.

AUTO SUB SCALE OFF/ON

(Turns OFF/ON the function for automatically scaling the sub scale following calculation.)
When set to ON, during trace C display, SUB LOG or SUB LIN and OFFSET LEVEL
change automatically. When these are changed, the displayed waveform is redrawn
according to the changed scale.

When set to ON, is displayed at the bottom of the screen in inverse video.

SUB REF LVL POSITION **DIV

(Sets the sub scale REF position.)
The REF position is set at DIV number **, counting from the bottom of the screen.
The setting range is 0 to 12. Settings can be adjusted in steps of 1. The value changes in
steps of 1-2-5 if you press the COARSE key.

5.3 Sub Scale

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5.4 Setting the Reference Level

Procedure

There are two ways of setting the reference level.

• Press the

REF LEVEL soft key.

• Use the one-action key.
The following explains these procedures.

Settings by Pressing the REF LEVEL Soft Key (Log Scale)

1.

Press LEVEL. The soft key menu for vertical axis settings appears along with the

reference level setting screen.

2.

When the vertical axis is not using a log scale, press the LOG SCALE soft key. If

a log scale is displayed, continue to step 4.

3.

Press the REF LEVEL soft key. The reference level setting screen is displayed.

4.

Enter a reference value using the rotary knob, arrow keys, or numeric key pad.

5.

Press ENTER.

Note

The vertical axis setting is applied in real time on the waveform display.

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Setting by Pressing the REF LEVEL Soft Key (Linear Scale)

1.

Press LEVEL. The soft key menu for vertical axis settings appears along with the

reference level setting screen.

2.

When the vertical axis is not using a linear scale, press the LIN SCALE soft key. If

a linear scale is displayed, continue to step 4.

3.

Press the REF LEVEL soft key. The reference level setting screen is displayed.

4.

Enter a reference value using the rotary knob, arrow keys, or numeric key pad.

When a value is input a soft key menu for selecting the instrument appears.

5.

Press the soft key corresponding to the desired units. The reference level is set.

Note

When entered with the rotary knob or arrow keys, the reference level is set using the current

units.

5.4 Setting the Reference Level

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Setting by Using the One-Action Key

Sets the peak level of the waveform as the reference level.

1.

Press LEVEL.

2.

Press the PEAK -> REF LEVEL soft key. The specified reference level is

displayed, and the displayed waveform is redrawn according to the changed
reference level.

Automatically sets the peak level of the waveform measured every sweep

as the reference level.

3.

Continuing on from step 1, press the AUTO REF LEVEL OFF/ON soft key to

select ON.

Note

• Sets the peak level of the measured waveform of the active trace as the reference level.

• This does not operate if the active trace is not set to WRITE (i.e., if it is set to MAX HOLD,
MIN HOLD, CALCULATE, or ROLL AVG).

• When set to ON, is displayed at the bottom of the screen in inverse video.

Sets the moving marker level as the reference level.

1.

Press MARKER.

2.

With the moving marker displayed, press the MARKER-> REF LEVEL soft key.

The specified reference level is displayed, and the displayed waveform is redrawn
according to the changed reference level.

For details on displaying moving markers, see the explanation in section 6.8.

5.4 Setting the Reference Level

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Explanation

Log Scale (REF LEVEL)

The setting range for the log scale reference level is -90.0–30.0 dBm. Settings can be
adjusted in steps of 0.1. The value changes in steps of 1 if you press the COARSE key.

Linear Scale (REF LEVEL)

The setting range for the linear scale reference level is 1.00 pW–1000 mW.

When1.00to9.99(pW,nW,μW,mW),canbesetinstepsof0.01.
When10.0to99.9(pW,nW,μW,mW),canbesetinstepsof0.1.
When100to999(pW,nW,μW,mW),canbesetinstepsof1.

If you press the COARSE key you can change the setting in 1-2-5 steps,

for example: 1pW -> 2pW -> 5pW -> 10pW -> 20pW.
If you make a change such as changing 999 to 1.00 or 1.00 to 999, the instrument will be
changed.

(Example: Changing pW to nW or changing nW to pW)

One-Action Keys

This is the general name for a key that uses data from the active trace waveform (the
currently displayed waveform) to set measurement conditions.
Setting conditions requires that a waveform is displayed for the active trace.

PEAK → REF LEVEL

Sets the peak level of the waveform of the active trace to the reference level.
Displays the specified reference level (peak level value) and waveform in the reference
level setting screen. The reference level setting can be changed after being set initially.
The setting can be changed within the range of -90.0–+30.0 dBm for LOG scale, or 1.00
pW–1000 mW for linear scale. If the peak level value exceeds the allowed range, it is set
to the nearest value in the range and a warning is displayed.

MARKER→ REF LEVEL

This key is used to set the moving marker level as the reference level.
Displays the specified reference level and waveform in the reference level setting screen.
The reference level setting can be changed after being set initially. The setting can be
changed within the range of -90.0–+30.0 dBm for LOG scale, or 1.00 pW–1000 mW for
linear scale.

If the moving marker value exceeds the allowed range, it is set to the nearest value in the

rangeandawarningisdisplayed.Inthefollowingstates,theMARKER→REFLEVEL

key is disabled.

• When the moving marker is OFF

• When both split screens are on HOLD

5.4 Setting the Reference Level

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5.5 Center Wavelength (Center Frequency) Setting

Procedure

The following are three ways of setting the center wavelength (center frequency).

• Press the

CENTER WL or CENTER FREQ soft key.

• Press the

START WL/STOP WL or START FREQ/STOP FREQ soft key.

• Use the one-action key (soft key).

The following explains these procedures.

Setting by Pressing the CENTER WL or CENTER FREQ Soft Key

1.

Press CENTER. The soft key menu for center wavelength or center frequency

appears along with the center wavelength or center frequency setting screen.

2.

Press the CENTER WL soft key for center wavelength or the CENTER FREQ soft

key for center frequency.

3.

Enter a center wavelength or center frequency using the rotary knob, arrow keys,

or numeric key pad.

4.

Press nm/ENTER.

Note

• It is not necessary to press nm/ENTER when using the rotary knob or arrow keys.

• The set value is applied to the measurement conditions area.

• When a setting is changed,

appears in the measurement conditions area.

• If a value outside the setting range is entered, the nearest permitted value is set.

For instructions on switching the wavelength and frequency displays, see section 5.2.

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Setting with the START WL/STOP WL or START FREQ/STOP FREQ Soft Key

1.

Press CENTER. The soft key menu for center wavelength or center frequency

settings appears.

Setting the Start Wavelength or Start Frequency

2.

Press the START WL soft key for start wavelength or the START FREQ soft

key for start frequency. The start wavelength or start frequency setting screen is
displayed.

3.

Enter a start wavelength or start frequency using the rotary knob, arrow keys, or

numeric key pad.

4.

Press nm/ENTER.

Setting the Stop Wavelength or Stop Frequency

5.

Press the STOP WL soft key for stop wavelength or the STOP FREQ soft key

for stop frequency. The stop wavelength or stop frequency setting screen is
displayed.

6.

Enter a stop wavelength or stop frequency using the rotary knob, arrow keys, or

numeric key pad.

7.

Press nm/ENTER.

Note

• It is not necessary to press nm/ENTER when using the rotary knob or arrow keys.

• The set value is applied to the measurement conditions area.

• When a setting is changed,

appears in the measurement conditions area.

• If a value outside the setting range is entered, the nearest permitted value is set.

For instructions on switching the wavelength and frequency displays, see section 5.2.

5.5 Center Wavelength (Center Frequency) Settings

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Setting by Using the One-Action Key

You can set the center wavelength or center frequency by pressing the one-action key
one time in the soft key menu that appears when you press CENTER.

1.

Press CENTER.

2.

For the center wavelength setting, when using peak wavelength or peak

frequency, press the PEAK->CENTER soft key. For THRESH 3dB center
wavelength or center frequency, press the MEAN WL->CENTER soft key. When
using the currently displayed ZOOM scale, press the VIEW->MEAS soft key. The
specified center wavelength or center frequency is displayed, and the displayed
waveform is redrawn according to the changed center wavelength.

The peak wavelength or peak frequency of the waveform measured every sweep

can be set automatically to the center wavelength or center frequency.

3.

Continuing on from step 1, press the AUTO CENTER OFF/ON soft key to select

ON.

Setting peak to center

Setting THRESH 3dB center to center

Automatic setting

Using zoom scale

Also, you can set the wavelength of the moving marker placed on the measured

waveform as the center wavelength or center frequency.

1.

Press MARKER.

2.

With the moving marker displayed, press the MARKER-> CENTER soft key. The

specified center wavelength or center frequency is displayed, and the displayed
waveform is redrawn according to the changed center wavelength or center
frequency.

For details on displaying moving markers, see the explanation in section 6.8.

5.5 Center Wavelength (Center Frequency) Settings

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Explanation

Center Wavelength

The setting range is 600.000 to 1700.000 nm.
If you press the COARSE key you can use the rotary knob or arrow keys to change the
numerical value in 1 nm steps. The value changes in 0.1 nm steps if you do not press the
COARSE key.

Start Wavelength

The setting range is 50,000 to 1700.000 nm.

Stop Wavelength

The setting range is 600.000 to 2250.000 nm.

Note

• When the start or stop wavelength is set, one wavelength becomes fixed, and this changes
the value of the sweep width. In addition, the center wavelength value is also changed at the
same time.

• Changing the center wavelength does not change the sweep width.

AUTO CENTER OFF/ON

This key sets whether the PEAK→CENTER soft key functions for each sweep.
When this key is set to ON, the peak is searched in the active trace waveform and set
as the center wavelength automatically for each sweep. The active trace must be set to

WRITE. When ON is selected, at the bottom of the screen is displayed in reverse
video.

One-Action Keys

This is the general name for a key that uses data from the active trace waveform (the
currently displayed waveform) to set measurement conditions.
Setting conditions requires that a waveform is displayed for the active trace.

PEAK →CENTER

Sets the wavelength of the peak value to the center wavelength.
After execution, the center wavelength set in the center wavelength setting screen is
displayed. The center frequency can be changed after the setting is made initially.

MEAN WL→CENTER

Sets the average of two wavelengths falling below the threshold value (3 dB) from the
waveform peak of the active trace to the center wavelength. The center wavelength can
be changed after the setting is made initially.

VIEW→MEAS

This key is used to set the currently set ZOOM scale (ZOOM CENTER, ZOOM SPAN,
ZOOM START, ZOOM STOP) as the measurement scale (CENTER, START, STOP,
SPAN).
When you press this key, the current waveform display scale is set as the measurement
scale for the next sweep.

5.5 Center Wavelength (Center Frequency) Settings

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Center Frequency

The setting range is 176.5000 to 500.0000 THz.
If you press the COARSE key you can use the rotary knob or arrow keys to change the
numerical value in 0.1 THz steps. The value changes in 0.01 THz steps if you do not
press the COARSE key.

Start Frequency

The setting range is 11.5000 to 500.0000 THz.

Stop Frequency

The setting range is 176.5000 to 665.0000 THz.

Note

• When the start or stop frequency is set, one frequency becomes fixed, and this changes
the value of the sweep width. In addition, the center frequency value is also changed at the
same time.

• Changing the center frequency does not change the sweep width.

AUTO CENTER OFF/ON

This key sets whether the PEAK→CENTER soft key functions for each sweep.
When this key is set to ON, the peak is searched in the active trace waveform and set
as the center frequency automatically for each sweep.The active trace must be set to

WRITE. When ON is selected, at the bottom of the screen is displayed in reverse
video.

One-Action Keys

You can set the center frequency with the one-action key in the same manner as for the
wavelength.

PEAK →CENTER

Sets the frequency of the waveform peak value of the active trace to the center
frequency. After execution, the center frequency set in the center frequency setting
screen is displayed. The center frequency can be changed after the setting is made
initially.

MEAN WL→CENTER

Sets the average of two frequencies falling below the threshold value (3 dB) from the
waveform peak of the active trace to the center frequency. The center frequency can be
changed after the setting is made initially.

VIEW→MEAS

This key is used to set the currently set ZOOM scale (ZOOM CENTER, ZOOM SPAN,
ZOOM START, ZOOM STOP) as the measurement scale (CENTER, START, STOP,
SPAN). When you press this key, the current waveform display scale is set as the
measurement scale for the next sweep.

5.5 Center Wavelength (Center Frequency) Settings

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5.6 Sweep Width Settings

Procedure

The following are three ways of setting the sweep width.

• Press the

SPAN WL or SPAN FREQ soft key.

• Press the

START WL/STOP WL or START FREQ/STOP FREQ soft key.

• Use the one-action key (soft key).

The following explains these procedures.

Setting by Pressing the SPAN WL or SPAN FREQ Soft Key

1.

Press SPAN. The soft key menu for sweep width settings appears along with the

sweep width setting screen.

2.

Press SPAN WL for wavelength measurement or SPAN FREQ for frequency

measurement.

3.

Enter a sweep width using the rotary knob, arrow keys, or numeric key pad.

4.

Press nm/ENTER.

Note

• It is not necessary to press nm/ENTER when using the rotary knob or arrow keys.

• The set value is applied to the measurement conditions area.

• When a setting is changed,

appears in the measurement conditions area.

• If a value outside the setting range is entered, the nearest permitted value is set.

For instructions on switching the wavelength and frequency displays, see section 5.2.

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Setting with the START WL/STOP WL or START FREQ/STOP FREQ Soft Key

1.

Press SPAN. The soft key menu for sweep width settings appears.

Setting the Start Wavelength or Start Frequency

2.

Press the START WL soft key for start wavelength or the START FREQ soft

key for start frequency. The start wavelength or start frequency setting screen is
displayed.

3.

Enter a start wavelength or start frequency using the rotary knob, arrow keys, or

numeric key pad.

4.

Press nm/ENTER.

Setting the Stop Wavelength or Stop Frequency

5.

Press the STOP WL soft key for stop wavelength or the STOP FREQ soft key

for stop frequency. The stop wavelength or stop frequency setting screen is
displayed.

6.

Enter a stop wavelength or stop frequency using the rotary knob, arrow keys, or

numeric key pad.

7.

Press nm/ENTER.

Note

• It is not necessary to press nm/ENTER when using the rotary knob or arrow keys.

• The set value is applied to the measurement conditions area.

• When a setting is changed,

appears in the measurement conditions area.

• If a value outside the setting range is entered, the nearest permitted value is set.

For instructions on switching the wavelength and frequency displays, see section 5.2.

5.6 Sweep Width Settings

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Setting by Using the One-Action Key

Setting the Sweep Width from the Measured Waveform

1.

Press SPAN.

2.

Press the Δλ→ SPAN soft key. Sets the span as six times the RMS 20 dB width of

the active trace measurement waveform.

Sets spacing between line markers 1 and 2 for sweep width.

1.

Press MARKER.

2.

Press the MORE 1/3 soft key.

3.

With the line markers 1 and 2 displayed, press the MK L1-L2 -> SPAN soft key.

Sets spacing between line markers 1 and 2 for sweep width.

For details on displaying line markers, see the explanation in section 6.8.

Note

• If only one of the line markers is displayed, for L1, the wavelength on the right edge of the
screen is set to the measurement stop wavelength. For L2, the wavelength on the left edge
of the screen is set to the measurement start wavelength.

• The MKR L1-L2 ->SPAN soft key cannot be used under the following conditions.

• When both L1 and L2 are OFF.

• When both SPLIT screens are on HOLD.

• When the span of the active trace is 0 nm.

5.6 Sweep Width Settings

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Explanation

Wavelength Sweep Width

The available setting range is 0, and 0.1 to 1100.0 nm. If you press the COARSE key you
can use the rotary knob or arrow keys to change the numerical value in 1-2-5 steps. The
value changes in 1 nm steps if you do not press the COARSE key.

Start Wavelength

The setting range is 50,000 to 1700.000 nm. The value changes in 1 nm steps if you
press the COARSE key. If you do not press it, the value changes in 0.1 nm steps.

Stop Wavelength

The setting range is 600.000 to 2250.000 nm. The value changes in 1 nm steps if you
press the COARSE key. If you do not press it, the value changes in 0.1 nm steps.

Note

• Setting the sweep width changes the start wavelength and stop wavelength. The center
wavelength/frequency does not change.

• Changing the center wavelength changes the start wavelength and stop wavelength. The
sweep width does not change. When the start or stop wavelength is set, one wavelength
becomes fixed, and this changes the value of the sweep width. In addition, the center
wavelength value is also changed at the same time.

One-Action Keys

This is the general name for a key that uses data from the active trace waveform (the
currently displayed waveform) to set measurement conditions.
Setting conditions requires that a waveform is displayed for the active trace.

Δλ→SPAN

Sets the sweep width as six times the spectrum width (threshold 20 dB ) of the active
trace measurement waveform with the RMS method.

MKR L1-L2 →SPAN

Sets spacing between line markers 1 and 2 for sweep width.
The setting range is 0.1 to 1100 nm (in 0.1 nm steps).

Frequency Sweep Width

The allowed settings are 0 and the range of 0.01 to 330.000 THz.
If you press the COARSE key you can use the rotary knob or arrow keys to change the
numerical value in 1-2-5 steps. The value changes in 0.1 THz steps if you do not press
the COARSE key.

Start Frequency

The setting range is 11.5000 to 500,000 THz.
The value changes in 0.1 THz steps if you press the COARSE key. If you do not press it,
the value changes in 0.01 THz steps.

Stop Frequency

The setting range is 176.5000 to 665.0000 THz.
The value changes in 0.1 THz steps if you press the COARSE key. If you do not press it,
the value changes in 0.01 THz steps.

5.6 Sweep Width Settings

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5.7 Wavelength (Frequency) Resolution Settings

Procedure

1.

Press SETUP. The soft key menu for sweep condition settings appears.

2.

Press the RESOLUTION soft key. The resolutions that can be set appear in the

soft key menu.

3.

Press the soft key corresponding to the desired resolution. The screen returns

to the previous stage, and the value specified by the RESOLUTION soft key is
displayed.

Note

• When entering an arbitrary value using the rotary knob, arrow keys, or numeric key pad in
the resolution screen that appears when you press the RESOLUTION soft key, the soft key
value that is closest to the entered value is set.

• The instrument displays if the settings for span, the number of sampling points, and

the resolution are inappropriate. When is displayed, normal measurement is not
possible.

Corrective Action When “UNCAL” Is Displayed

Perform the following steps.

• Decrease the span.

• Increase the number of samples.

• Lower the resolution (increase the value).

• Select AUTO with the SAMPLING POINT soft key under SETUP.

The “UNCAL” display disappears if the span, number of samples, and the resolution
settings are appropriate.

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Correcting the Resolution

1.

Press SETUP. The soft key menu for sweep condition settings appears.

2.

Press the MORE 1/2 soft key.

3.

Press the RESOLN CORRECT OFF ON soft key. Each time you press the soft

key the setting toggles between ON and OFF.

Note

• Since the wavelength resolution function is set according to the monochromator slit width,
the setting resolution and actual resolution may not match. For this instrument, if the
resolution is set to 0.1 nm, the actual resolution will be 0.09 nm for a 1310 nm wavelength,
and 0.06 nm for a 1550 nm wavelength.

• If the resolution correction function is turned ON, measured data is processed by the
software so that it matches the set resolution.
In the following cases, the resolution correction function has no effect even when turned ON.

• When the set resolution is 0.02 nm

• When the measured wavelength is 1250 nm or less

• Turn OFF the resolution correction function when performing measurement for which the
level accuracy is guaranteed.

5.7 Wavelength (Frequency) Resolution Settings

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Explanation

Conditions under Which “UNCAL” Is Displayed

“UNCAL” is displayed when a single or repeat sweep is started based on the following
relationship between span, setting resolution, and set number of samples:

Setting resolution

Span

x 5 < Set number of samples - 1

Waveforms with Resolutions of 0.020 nm

When the resolution is set to 0.020 nm for measurements of a light source such as a
DFB laser in which with the spectral width is narrower than the instrument’s resolution,
very small spikes may occur at the skirts of the waveform. This type of spike occurs due
to characteristics of the optical block and is not an indication of any problem. Even if such
spikes occur, satisfactory performance in terms of resolution, dynamic range, and the like
can be ensured. These spikes will disappear if the resolution is set to a coarser value.

Ripples in the 1350–1450 nm Area

Water (OH-) ions present in the monochromator absorb light in the 1350–1450 nm area,
resulting in ripples in the measurement waveform. Either set a coarser resolution or use
the monochromator in a lower-humidity environment to reduce the amount of ripples.

5.7 Wavelength (Frequency) Resolution Settings

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5.8 Sampling Point/Interval Settings

Procedure

The following are three ways in which the number of samples can be entered.

• Setting the number of samples directly

• Setting by the sampling interval

• Automatically setting the optimum number of samples or the sampling interval
according to the sweep width (span) and resolution setting

1.

Press SETUP. The soft key menu for sweep condition settings appears.

2.

Press the SAMPLING POINT or SAMPLING INTERVAL soft key to set the

sampling point or sampling interval, respectively. To automatically set the sampling
points and interval according to the span and wavelength (frequency) resolution
settings, press SAMPLING POINT AUTO. The sampling points or interval setting
screen is displayed.

If you pressed

SAMPLING POINT AUTO, the sampling points and interval are set

automatically.

3.

Enter a number of samples or interval using the rotary knob, arrow keys, or

numeric key pad.

4.

Press ENTER. The sampling points or interval are set.

Automatic setting

Sets

Sets

sampling interval

sampling points

Note

• The instrument displays if the settings for span, the number of sampling points, and

the resolution are inappropriate. When is displayed, normal measurement is not

possible.

• See section 5.7 for the corrective actions when is displayed.

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Explanation

Sampling points (the number of points measured in a single sweep)

Sampling points are the number of points measured within the range of the specified
span.
The setting range is 101 to 50001.

Relationship between Sampling Points, Interval, and Span

The relationship between the number of samples, the interval, and the span is as follows.

Interval

Span

Number of sampling points =

+ 1

Given the same span, the sampling points are automatically determined when the
interval is known, and viceversa.
For information about the allowed setting for the span, see the explanation in section 5.6,
“Sweep Width Setting.”

Note

• Increasing the number of sampling points or decreasing the sampling interval reduces the
sweeping speed.

• Settings that would cause the number of samples in the sweep range to be extremely few
cannot be entered.

• If the setting for the number of samples is changed, the sampling interval value also
changes accordingly.

Relationship with Wavelength (Frequency) Resolution

If settings are entered such that the sampling interval determined by the settings for the
span and number of samples is extremely long relative to the wavelength (frequency)
resolution, data may be lost. Enter settings that are appropriate for the resolution.

5.8 Sampling Point/Interval Settings

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5.9 Sensitivity Settings

Procedure

1.

Press SETUP. The soft key menu for sweep condition settings appears.

2.

Press the SENS/MODE soft key. Seven sensitivity choices appear in the soft key

menu.

3.

Press the soft key corresponding to the desired choice. The screen returns to the

previous stage, and the value specified by the SENS/MODE soft key is displayed.

CHOP MODE Settings

2.

Press the SENS/MODE soft key.

3.

Press the CHOP MODE soft key.

4.

Press the SWITCH soft key.

5.

To turn CHOP MODE OFF, press the OFF soft key.

Note

If you set the CHOP MODE to SWITCH, the corresponding sensitivity soft key display will
change to MID/SW or HIGH1/SW–HIGH3/SW.

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Explanation

CHOP MODE

This mode activates the internal chopper of the monochromator.
Stray light specific to the monochromator is reduced by turning the chopper.
When CHOP MODE is set to SWITCH, measurements of better S/N can be made. You
can set the CHOP MODE to SWITCH if the sensitivity setting is HIGH1–HIGH3 or MID.

CHOP MODE Function List

CHOP

MODE

Function Merit Defect

OFF

Measurement according to
the stray light.

Measurement time
is rapid even for
high sensitivity
measurements.

Since the stray light
is also measured, the
low level component is
not accurate if the light
source is of high power.

Stray light suppression ratio:
40 dB or more

SWITCH

Two sweeps per
measurement are

performed.Therstsweep

measures the stray light
component, and high
dynamic measurement is
possible through subtraction.

Short-duration
measurement can be
taken with stray light
removed.

If the measurement
duration is long, it is

inuencedbytemporal

changes in the
measured light.

Stray light suppression ratio:
60 dB or more

Stray Light from the Monochromator

The instrument has a newly designed, high-performance monochromator. Depending
on the measurement conditions, stray light at a level 30 to 50 dB below the original
spectrum, as well as other stray light specific to the monochromator may occur in
wavelength areas 100 to 200 nm from the peak wavelength. If this stray light is likely to
have a severe impact on measurements, the sensitivity can be set to MID or HIGH 1–3
and CHOP MODE can be set to SWITCH in order to reduce the effects of the stray light.

Waveform with CHOP MODE OFF CHOP MODE set to SWITCH

5.9 Sensitivity Settings

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5.10 Averaging Times Setting

Procedure

1.

Press SETUP. The soft key menu for sweep condition settings appears.

2.

Press the AVERAGE TIMES soft key. The averaging times setting screen is

displayed.

3.

Enter a number of averaging times using the rotary knob, arrow keys, or numeric

key pad.

4.

Press ENTER. The value specified by the AVERAGE TIMES soft key is

displayed.

Note

Increasing the averaging times reduces the sweeping speed but the S/N improves.

Explanation

AVERAGE TIMES

This key is used to set the average times for each point.
The setting range is 1 to 999.
If you press the COARSE key you can use the rotary knob or arrow keys to change
the numerical value in 1-2-5 steps. The value changes in 1 step if you do not press the
COARSE key.

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5.11 Trace Settings

Procedure

The following explains selecting a trace, writing waveform data, and displaying the data
on screen.

1.

Press TRACE. The soft key menu for traces appears.

2.

Press the ACTIVE TRACE soft key. Traces A through G appear in soft keys.

3.

Press the soft key corresponding to the trace you wish to use. That trace is set as

the active trace (in the example below, this will be trace B).

4.

Press the VIEW B soft key and select DISP.

5.

Press the WRITE B soft key. Trace B is placed in write mode.

Note

Waveforms of traces for which VIEW A–VIEW G are set to BLANK cannot be displayed on
screen.