Agilent Technologies 81480A, 81640A, 81642A, 81680A, 81689A User Manual

Agilent 81480A and

Agilent 81680A, 81640A, 81682A, 81642A, & 81689A

Tunable Laser Modules

User’s Guide

S1

Notices

This document contains proprietary information that is protected by copyright. All rights are reserved.

No part of this document may reproduced in (including electronic storage and retrieval or translation into a foreign language) without prior agreement and written consent from Agilent Technologies Deutschland GmbH as governed by United States and international copywright laws.

Copyright 2001 by:

Agilent Technologies Deutschland GmbH Herrenberger Str. 130

71034 Böblingen

Germany

Subject Matter

The material in this document is subject to change without notice.

Agilent Technologies makes no warranty of any kind with regard to this printed material, including, but not limited to, the implied warranties of merchantability and fitness for a particular purpose.

Agilent Technologies shall not be liable for errors contained herein or for incidental or consequential damages in connection with the furnishing, performance, or use of this material.

Printing History

New editions are complete revisions of the guide reflecting alterations in the functionality of the instrument. Updates are occasionally made to the guide between editions. The date on the title page changes when an updated guide is published. To find out the current revision of the guide, or to purchase an updated guide, contact your Agilent Technologies representative.

Control Serial Number: First Edition applies directly to all instruments.

Warranty

This Agilent Technologies instrument product is warranted against defects in material and workmanship for a period of one year from date of shipment. During the warranty period, Agilent will, at its option, either repair or replace products that prove to be defective.

For warranty service or repair, this product must be returned to a service facility designated by Agilent. Buyer shall prepay shipping charges to Agilent and Agilent shall pay shipping charges to return the product to Buyer. However, Buyer shall pay all shipping charges, duties, and taxes for products returned to Agilent from another country.

Agilent warrants that its software and firmware designated by Agilent for use with an instrument will execute its programming instructions when properly installed on that instrument. Agilent does not warrant that the operation of the instrument, software, or firmware will be uninterrupted or error free.

Limitation of Warranty

The foregoing warranty shall not apply to defects resulting from improper or inadequate maintenance by Buyer, Buyer-supplied software or interfacing, unauthorized modification or misuse, operation outside of the environmental specifications for the product, or improper site preparation or maintenance.

No other warranty is expressed or implied. Agilent Technologies specifically disclaims the implied warranties of Merchantability and Fitness for a Particular Purpose.

Exclusive Remedies

The remedies provided herein are Buyer’s sole and exclusive remedies. Agilent Technologies shall not be liable for any direct, indirect, special, incidental, or consequential damages whether based on contract, tort, or any other legal theory.

Assistance

Product maintenance agreements and other customer assistance agreements are available for Agilent Technologies products. For any assistance contact your nearest Agilent Technologies Sales and Service Office.

Certification

Agilent Technologies Inc. certifies that this product met its published specifications at the time of shipment from the factory.

Agilent Technologies further certifies that its calibration measurements are traceable to the United States National Institute of Standards and Technology, NIST (formerly the United States National Bureau of Standards, NBS) to the extent allowed by the Institutes’s calibration facility, and to the calibration facilities of other International Standards Organization members.

ISO 9001 Certification

Produced to ISO 9001 international quality system standard as part of our objective of continually increasing customer satisfaction through improved process control.

Sixth Edition

81680-90014 E0101

First Edition:

E0599: May 1999

Second Edition:

E1099: October 1999

Third Edition:

E1299: December 1999

Fourth Edition:

E0300: March 2000

Fifth Edition:

E0900: September 2000

Sixth Edition:

E0101: January 2001

2	Agilent 81480A and 81680A, 40A, 82A, 42A, & 89A Tunable Laser Modules User’s Guide,
	Sixth Edition

Safety Summary

	Safety Summary
	The following general safety precautions must be observed during all
	phases of operation, service, and repair of this instrument. Failure to
	comply with these precautions or with specific warnings elsewhere in
	this manual violates safety standards of design, manufacture, and
	intended use of the instrument. Agilent Technologies Inc. assumes no
	liability for the customer’s failure to comply with these requirements.
	Before operation, review the instrument and manual, including the
	red safety page, for safety markings and instructions. You must follow
	these to ensure safe operation and to maintain the instrument in safe
	condition.
W A R N I N G	The WARNING sign denotes a hazard. It calls attention to a procedure,
	practice or the like, which, if not correctly performed or adhered to,
	could result in injury or loss of life. Do not proceed beyond a
	WARNING sign until the indicated conditions are fully understood and
	met.
	Safety Symbols
	The apparatus will be marked with this symbol when it is necessary
	for the user to refer to the instruction manual in order to protect the
	apparatus against damage.
	Hazardous laser radiation.
	Initial Inspection
	Inspect the shipping container for damage. If there is damage to the
	container or cushioning, keep them until you have checked the
	contents of the shipment for completeness and verified the instrument
	both mechanically and electrically.
	The Performance Tests give procedures for checking the operation of
	the instrument. If the contents are incomplete, mechanical damage or
	defect is apparent, or if an instrument does not pass the operator’s
	checks, notify the nearest Agilent Technologies Sales/Service Office.
W A R N I N G	To avoid hazardous electrical shock, do not perform electrical tests
	when there are signs of shipping damage to any portion of the outer
	enclosure (covers, panels, etc.).

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Safety Summary

W A R N I N G	You MUST return instruments with malfunctioning laser modules to
	an Agilent Technologies Sales/Service Center for repair and
	calibration.

Line Power Requirements

The Agilent 81480A, Agilent 81680A, Agilent 81640A, Agilent 81682A, Agilent 81642A, & Agilent 81689A Tunable Laser Modules operate when installed in the Agilent 8164A Lightwave Measurement System. The Agilent 81689A also operates when installed in the Agilent 8163A Lightwave Multimeter or Agilent 8166A Lightwave Multichannel System.

Operating Environment

The safety information in the Agilent 8163A Lightwave Multimeter, Agilent 8164A Lightwave Measurement System, & Agilent 8166A Lightwave Multichannel System User’s Guide summarizes the operating ranges for the Agilent 81480A, Agilent 81680A,

Agilent 81640A, Agilent 81682A, Agilent 81642A, & Agilent 81689A Tunable Laser Modules. In order for these modules to meet specifications, the operating environment must be within the limits specified for your mainframe.

	Input/Output Signals
C A U T I O N	There are two BNC connectors on the front panel of the
	Agilent 81480A, Agilent 81680A, Agilent 81640A, Agilent 81682A, and
	Agilent 81642A; a BNC input connector and a BNC output connector.
	There is one BNC connector on the front panel of the Agilent 81689A -
	a BNC input connector.
	An absolute maximum of ±6 V can be applied as an external voltage to
	any BNC connector.

	Storage and Shipment
	This module can be stored or shipped at temperatures between
	−40°C and +70°C. Protect the module from temperature extremes that
	may cause condensation within it.
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Safety Summary

Initial Safety Information for Tunable Laser

Modules

The Specifications for these modules are as follows:

Table 1 Tunable Laser Modules Laser Safety Information

	Agilent 81480A	Agilent 81680A	Agilent 81640A	Agilent 81682A	Agilent 81642A	Agilent 81689A
Laser Type	FP-Laser	FP-Laser	FP-Laser	FP-Laser	FP-Laser	FP-Laser
	InGaAsP	InGaAsP	InGaAsP	InGaAsP	InGaAsP	InGaAsP
Wavelength range	1370-1480 nm	1400-1670 nm	1400-1670 nm	1400-1670 nm	1400-1670 nm	1400-1670 nm
Max. CW output power*	<15 mW	<15 mW	<15 mW	<15 mW	<15 mW	<15 mW
Beam waist diameter	9 m	9 m	9 m	9 m	9 m	9 m
Numerical aperture	0.1	0.1	0.1	0.1	0.1	0.1
Laser Class according to	3A	3A	3A	3A	3A	3A
IEC 60825-1 (1998)- International
Max. permissible CW output	50 mW	50 mW	50 mW	50 mW	50 mW	50 mW
power - IEC**
Laser Class according to	IIIb	IIIb	IIIb	IIIb	IIIb	IIIb
FDA 21 CFR 1040.10 (1995) - USA
Max. permissible CW output	500 mW	500 mW	500 mW	500 mW	500 mW	500 mW
power - FDA**

* Max. CW output power is defined as the highest possible optical power that the laser source can produce at its output connector. ** Max. permissible CW output power is the highest optical power that is permitted within the appropriate laser class.

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Safety Summary

Laser Safety Labels

These laser safety warning labels are fixed on the outside of the

Agilent 8164A Lightwave Measurement System before shipment.

Figure 1 USA Safety Labels (81480A, 81680A, 81640A, 81682A, 81642A, 81689A)

These laser safety warning labels are fixed on the outside of the Agilent 8164A

Lightwave Measurement System before shipment.

Figure 2 Non-USA Safety Labels (81480A, 81680A, 81640A, 81682A, 81642A, 81689A)

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Safety Summary

Top View

A sheet of laser safety warning labels are included with the instrument. You MUST stick the labels in the local language onto the outside of the instrument, in a position where they are clearly visible to anyone using the instrument.

See page 6

See page 6

Figure 3 Position of Safety Labels on Backloadable Tunable Laser Modules

These labels are applied in these positions to every Agilent 81480A,

Agilent 81680A, Agilent 81640A, Agilent 81682A, and Agilent 81642A

Tunable Laser Module before shipment.

See page 6

See page 6

See page 6

See page 6

Figure 4 Position of Safety Labels on Agilent 81689A Tunable Laser Module

These labels are applied in these positions to every Agilent 81689A

Tunable Laser Module before shipment.

Agilent 81480A and 81680A, 40A, 82A, 42A, & 89A Tunable Laser Modules User’s Guide, Sixth Edition

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Safety Summary

W A R N I N G	Please pay attention to the following laser safety warnings:
	• Under no circumstances look into the end of an optical cable
	attached to the optical output when the device is operational. The
	laser radiation can seriously damage your eyesight.
	• Do not enable the laser when there is no fiber attached to the optical
	output connector.
	• The laser is enabled by pressing the gray button close to the optical
	output connector on the front panel of the module. The laser is on
	when the green LED on the front panel of the instrument is lit.
	• The use of optical instruments with this product will increase eye
	hazard.
	• The laser module has a built-in safety circuitry which will disable
	the optical output in the case of a fault condition.
W A R N I N G	Refer Servicing only to qualified and authorized personnel.

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The Structure of this Manual

The Structure of this Manual

This manual is divided into two categories:

•Getting Started

This section gives an introduction to the Tunable Laser modules. and aims to make these modules familiar to you:

–“Getting Started with Tunable Laser Sources” on page 21.

•Additional Information

This is supporting information of a non-operational nature. this contains information concerning accessories, specifications, and performance tests:

–“Accessories” on page 31,

–“Specifications” on page 39, and

–“Performance Tests” on page 57.

Conventions used in this manual

•Hardkeys are indicated by italics, for example, Config, or Channel.

•Softkeys are indicated by normal text enclosed in square brackets, for example, [Zoom] or [Cancel].

•Parameters are indicated by italics enclosed by square brackets, for example, [Range Mode], or [MinMax Mode].

•Menu items are indicated by italics enclosed in brackets, for example, <MinMax>, or <Continuous>.

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The Structure of this Manual

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Table of Contents

Table of Contents

Safety Summary	3
Safety Symbols	3
Initial Inspection	3
Line Power Requirements	4
Operating Environment	4
Input/Output Signals	4
Storage and Shipment	4
Initial Safety Information for Tunable Laser Modules	5
Laser Safety Labels	6
The Structure of this Manual	9
Conventions used in this manual	9
Getting Started with Tunable Laser Sources	21
What is a Tunable Laser ?	23

Accessories

Agilent 81480A, 81680A/82A/40A/42A Tunable Laser Modules

24
Agilent 81689A Tunable Laser Module	26
Optical Output	27
Polarization Maintaining Fiber	27
Angled and Straight Contact Connectors	27
Signal Input and Output	29
	31

Modules and Options	33
Modules	34
User’s Guides	35
Options	35
Option 003 - Agilent 81682A, Agilent 81642A	35
Option 021 - Agilent 81689A	35
Option 022 - Agilent 81689A	36
Option 071 - All Tunable Laser Modules	36
Option 072 - All Tunable Laser Modules	36
Connector Interfaces and Other Accessories	36
Options 071, 021: Straight Contact Connectors	36

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Table of Contents

Specifications

Options 072, 022: Angled Contact Connectors	37
	39

	Definition of Terms	41
	Absolute Wavelength Accuracy	41
	Effective Linewidth	41
	Linewidth	42
	Minimum Output Power	42
	Mode-Hop Free Tuning Range	42
	Modulation Extinction Ratio	42
	Modulation Frequency Range	43
	Output Power	43
	Output Isolation	43
	Peak Power	43
	Polarization Extinction Ratio	43
	Power Flatness Over Modulation	44
	Power Flatness Versus Wavelength	44
	Power Linearity	44
	Power Repeatability	44
	Power Stability	45
	Relative Intensity Noise (RIN)	45
	Relative Wavelength Accuracy	45
	Return Loss	45
	Sidemode Suppression Ratio	46
	Signal-to-Source Spontaneous Emission (SSE) Ratio	46
	Signal-to-Total-Source Spontaneous Emission	46
	Wavelength Range	47
	Wavelength Repeatability	47
	Wavelength Resolution	47
	Wavelength Stability	47
	Tunable Laser Module Specifications	48
	Supplementary Performance Characteristics	54
	Operating Modes	54
	Internal Digital Modulation 1	54
	External Digital Modulation 1	54
	External Analog Modulation 1	54
	External Wavelength Locking (Agilent 81680A/40A/82A/42A)	54
	Coherence Control (Agilent 81680A/40A/82A/42A)	54
	Continuous Sweep (Agilent 81680A/40A/82A/42A)	55
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	Table of Contents
	Stepped Mode (Agilent 81680A/40A/82A/42A)	55
	General	55
	Output Isolation (typ.):	55
	Return loss (typ.):	55
	Polarization Maintaining Fiber (Options 071, 072):	55
	Laser Class:	55
	Recalibration Period:	56
	Warm-up Time:	56
	Environmental	56
	Storage Temperature:	56
	Operating Temperature:	56
	Humidity:	56
	Performance Tests	57
	Required Test Equipment	59
	Test Record	60
	Test Failure	60
	Instrument Specification	60
	Performance Test Instructions	61
	General Test Setup	61
	Wavelength Tests	61
	General Settings of Wavelength Meters for all Wavelength Tests	62
	Wavelength Accuracy	62
	Relative Wavelength Accuracy	62
	Absolute Wavelength Accuracy	64
	Mode Hop Free Tuning	64
	Wavelength Repeatability	65
	Power Tests	67
	Calibration of the Agilent 81001FF Attenuation Filter	67
	Maximum Output Power	69
	Power Linearity	71
	Power Linearity - Low Power Test	71
	Example (Agilent 81680A Output 1)	73
	Power Linearity - High Power Test	73
	Power Linearity - Test Using Attenuation	75
	Power Flatness over Wavelength	76
	Power Flatness over Wavelength - Without Attenuation	76
	Power Flatness over Wavelength - Using Attenuation	77
	Power Stability	79
	Signal-to-Source Spontaneous Emission	81
	Signal-to-Source Spontaneous Emission Tests - High Power Outputs
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Table of Contents

	81
	Signal-to-Source Spontaneous Emission Tests - Low SSE Outputs	83
	Signal-to-Total-Source Spontaneous Emission	88
	Signal to Total SSE Tests - Low SSE Outputs	89
	Optional Test	95
	Signal to Total SSE Tests - High Power Outputs	95
	Test Record	99
	Agilent 81480A Performance Test	99
	Test Equipment Used	100
	Relative Wavelength Accuracy	101
	Mode Hop Free Tuning	103
	Wavelength Repeatability	104
	Maximum Power Test	105
	Power Linearity Output 1, Low SSE	106
	Power Linearity Output 2, High Power Upper Power Levels	106
	Power Linearity Output 2, High Power by attenuator	107
	Power Flatness	108
	Power Stability	109
	Signal-to-Source Spontaneous Emission - 81480A Output 2, High
	Power	109
	Signal-to-Source Spontaneous Emission - 81480A Output 1, Low SSE
	110
	Signal-to-Total-Source Spontaneous Emission - 81480A Output 1, Low
	SSE	111
	Optional Test: Signal-to-Total-Source Spontaneous Emission - 81480A
	Output 2, High Power	111
	Agilent 81680A Performance Test	113
	Test Equipment Used	114
	Relative Wavelength Accuracy	115
	Mode Hop Free Tuning	117
	Wavelength Repeatability	118
	Maximum Power Test	119
	Power Linearity Output 1, Low SSE	120
	Power Linearity Output 2, High Power Upper Power Levels	120
	Power Linearity Output 2, High Power by attenuator	121
	Power Flatness	122
	Power Stability	123
	Signal-to-Source Spontaneous Emission - 81680A Output 2, High
	Power	123
	Signal-to-Source Spontaneous Emission - 81680A Output 1, Low SSE
	124
	Signal-to-Total-Source Spontaneous Emission - 81680A Output 1, Low
	SSE	125
	Optional Test: Signal-to-Total-Source Spontaneous Emission - 81680A
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	Table of Contents
Output 2, High Power		125
Agilent 81640A Performance Test		127
Test Equipment Used		128
Relative Wavelength Accuracy		129
Relative Wavelength Accuracy Summary of all Repetitions		130
Relative Wavelength Accuracy Result		130
Absolute Wavelength Accuracy Result		130
Mode Hop Free Tuning		131
Wavelength Repeatability		132
Maximum Power Test		133
Power Linearity	Output 1, Low SSE134
Power Linearity Output 2, High Power Upper Power Levels		134
Power Linearity Output 2, High Power by Attenuator		135
Power Flatness		136
Power Stability		137
Signal-to-Source Spontaneous Emission - 81640A Output 2, High
Power		137
Signal-to-Source Spontaneous Emission - 81640A Output 1, Low SSE
138
Signal-to-Total-Source Spontaneous Emission - 81640A Output 1, Low
SSE		139
Optional Test - Signal-to-Total-Source Spontaneous Emission - 81640A
Output 2, High Power		139
Agilent 81682A Performance Test		141
Test Equipment Used		142
Relative Wavelength Accuracy		143
Mode Hop Free Tuning		145
Wavelength Repeatability		146
Maximum Power Test		147
Power Linearity - 81682A		147
Power Linearity 81682A #003 Upper Power Levels		148
Power Linearity 81682A #003 by Attenuator		149
Power Flatness		150
Power Stability		151
Signal-to-Source Spontaneous Emission - 81682A		151
Optional Test: Signal-to-Total-Source Spontaneous Emission - 81682A
152
Agilent 81642A Performance Test		153
Test Equipment Used		154
Relative Wavelength Accuracy		155
Mode Hop Free Tuning		157
Wavelength Repeatability		158
Maximum Power Test		159
Power Linearity - 81642A		159
Power Linearity 81642A #003 Upper Power Levels		160
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Table of Contents

	Power Linearity 81642A #003 by Attenuator	161
	Power Flatness	162
	Power Stability	163
	Signal-to-Source Spontaneous Emission - 81642A	163
	Optional Test: Signal-to-Total-Source Spontaneous Emission - 81642A
	164
	Agilent 81689A Performance Test	165
	Test Equipment Used	166
	Relative Wavelength Accuracy	167
	Wavelength Repeatability	168
	Maximum Power Test	169
	Power Linearity	169
	Power Flatness	170
	Power Stability	170
	Signal-to-Source Spontaneous Emission	170
	Cleaning Information	171
	Safety Precautions	173
	Why is it important to clean optical devices?	173
	What do I need for proper cleaning?	174
	Standard Cleaning Equipment	174
	Dust and shutter caps	174
	Isopropyl alcohol	175
	Cotton swabs	175
	Soft tissues	176
	Pipe cleaner	176
	Compressed air	176
	Additional Cleaning Equipment	177
	Microscope with a magnification range about 50X up to 300X	177
	Ultrasonic bath	177
	Warm water and liquid soap	178
	Premoistened cleaning wipes	178
	Polymer film	178
	Infrared Sensor Card	178
	Preserving Connectors	179
	Cleaning Instrument Housings	179
	Which Cleaning Procedure should I use ?	180
	How to clean connectors	180
	How to clean connector adapters	181
	How to clean connector interfaces	182
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Table of Contents

How to clean bare fiber adapters	183
How to clean lenses	184

How to clean instruments with a fixed connector interface

184

How to clean instruments with an optical glass plate 185 How to clean instruments with a physical contact interface

185

How to clean instruments with a recessed lens interface

186

How to clean optical devices which are sensitive to
mechanical stress and pressure	187
How to clean metal filters or attenuator gratings	188
Additional Cleaning Information	189
How to clean bare fiber ends	189
How to clean large area lenses and mirrors	189
Other Cleaning Hints	191

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Table of Contents

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List of Figures

List of Figures

Figure 1	USA Safety Labels (81480A, 81680A, 81640A, 81682A, 81642A, 81689A) . .	6
Figure 2	Non-USA Safety Labels (81480A, 81680A, 81640A, 81682A, 81642A, 81689A)	6
Figure 3	Position of Safety Labels on Backloadable Tunable Laser Modules . . .	7
Figure 4	Position of Safety Labels on Agilent 81689A Tunable Laser Module . . .	7
Figure 5	Agilent 81480A Tunable Laser Module (straight contact connectors) . . .	24
Figure 6	Agilent 81680A Tunable Laser Module (straight contact connectors) . . .	24
Figure 7	Agilent 81682A Tunable Laser Module (straight contact connector) . . .	24
Figure 8	Agilent 81640A Tunable Laser Module (straight contact connectors) . . .	24
Figure 9	Agilent 81642A Tunable Laser Module (straight contact connectors) . . .	24
Figure 10	Agilent 81689A Tunable Laser Module . . . . . . . . . .	26
Figure 11	PMF Output Connector . . . . . . . . . . . . . .	27
Figure 12	Angled and Straight Contact Connector Symbols . . . . . . . .	28
Figure 13	Agilent 81682A Tunable Laser Module (angled contact connector) . . .	28
Figure 14	Mainframes, Tunable Laser Modules, and Options . . . . . . .	33
Figure 15	Options 021, 071: Single-mode fiber/PMF with Straight Contact Connectors .	37
Figure 16	Options 022, 072: Single-mode fiber/PMF with Angled Contact Connectors .	38
Figure 17	Test Setup for Wavelength Tests . . . . . . . . . . . .	61
Figure 18	Calibration of the Agilent 81001FF Attenuation Filter, Reference Setup . .	67
Figure 19	Test Setup for Calibrating the Agilent 81001FF Attenuation Filter . . . .	68
Figure 20	Test Setup for the Maximum Output Power Tests. . . . . . . .	69
Figure 21	Test Setup for Low Power Linearity Tests. . . . . . . . . .	71
Figure 22	Test Setup for the Source Spontaneous Emission Test - High Power Outputs .	81
Figure 23	Transmission Characteristic of Fiber Bragg Grating . . . . . . .	84
Figure 24	Signal-to-Spectral SSE Measurement . . . . . . . . . .	84
Figure 25	Test Setup for Source Spontaneous Emission Test . . . . . . .	85

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List of Figures

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Getting Started with Tunable Laser Sources

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21

Getting Started with Tunable Laser Sources

This chapter describes the Agilent 81480A, Agilent 81680A,

Agilent 81640A, Agilent 81682A, Agilent 81642A, and Agilent 81689A Tunable Laser modules.

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What is a Tunable Laser ?

Getting Started with Tunable Laser Sources

What is a Tunable Laser ?

A Tunable Laser is a laser source for which the wavelength can be varied through a specified range. The Agilent Technologies range of Tunable Laser modules also allow you to set the output power, and to choose between continuous wave or modulated power.

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Getting Started with Tunable Laser Sources

What is a Tunable Laser ?

Agilent 81480A, 81680A/82A/40A/42A

Tunable Laser Modules

Figure 5 Agilent 81480A Tunable Laser Module (straight contact connectors)

Figure 6 Agilent 81680A Tunable Laser Module (straight contact connectors)

Figure 7 Agilent 81682A Tunable Laser Module (straight contact connector)

Figure 8 Agilent 81640A Tunable Laser Module (straight contact connectors)

	Figure 9 Agilent 81642A Tunable Laser Module (straight contact connectors)
24	Agilent 81480A and 81680A, 40A, 82A, 42A, & 89A Tunable Laser Modules User’s Guide,
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What is a Tunable Laser ?

Getting Started with Tunable Laser Sources

The Agilent 81480A and 81680A/82A/40A/42A Tunable Laser modules are back-loadable modules. To fit these modules into the Agilent 8164A mainframe see “How to Fit and Remove Modules” in the Agilent 8163A Lightwave Multimeter, Agilent 8164A, Lightwave Measurement System, & Agilent 8166A Lightwave Multichannel SystemUser’s Guide.

The Agilent 81480A and 81680A/82A/40A/42A Tunable Laser modules have a built-in wavelength control loop to ensure high wavelength accuracy. As these modules are all mode-hop free tunable with continuous output power, they qualify for the test of the most critical dense-Wavelength Division Multiplexer (dWDM) components.

The Agilent 81480A and Agilent 81640A/80A Tunable Laser modules are equipped with two optical outputs:

•Output 1, the Low SSE output, delivers a signal with ultra-low source spontaneous emission (SSE). It enables accurate crosstalk measurement of DWDM components with many channels at narrow spacing. You can characterize steep notch filters such as Fiber Bragg Gratings by using this output and a power sensor module.

•Output 2, the High Power output, delivers a signal with high optical power. You can adjust the signal by more than 60 dB by using the inbuilt optical attenuator.

The Agilent 81682A/42A Tunable Laser module delivers a signal with high optical power. If you choose Option 003, you can adjust the signal by more than 60 dB by using the in-built optical attenuator.

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Getting Started with Tunable Laser Sources

What is a Tunable Laser ?

Agilent 81689A Tunable Laser Module

Agilent 81689A with	Agilent 81689A with
Straight Contact Connector	Angled Contact Connector

Figure 10 Agilent 81689A Tunable Laser Module

The Agilent 81689A Tunable Laser module is a front-loadable module. To insert this module into the Agilent 8163A Lightwave Multimeter, Agilent 8164A Lightwave Measurement System or Agilent 8166A Lightwave Multichannel System see “How to Fit and Remove Modules” in the Agilent 8163A Lightwave Multimeter, Agilent 8164A Lightwave Measurement System, & Agilent 8166A Lightwave Multichannel System User’s Guide.

You can use the Agilent 81689A Tunable Laser module to set up a realistic multi-channel test-bed for DWDM transmission systems. Its continuous, mode-hop free tuning makes it quick and easy to set even the most complex configurations to the target wavelengths and power levels.

The Agilent 8163A Lightwave Multimeter, a Power Sensor module,and a Agilent 81689A Tunable Laser module together represent a smart loss-test set with selectable wavelength.

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Optical Output

Getting Started with Tunable Laser Sources

Optical Output

Polarization Maintaining Fiber

If you have an instrument with a polarization maintaining fiber (PMF), the PMF is aligned to maintain the state of polarization.

The fiber is of Panda type, with TE mode in the slow axis in line with the connector key. A well defined state of polarization ensures constant measurement conditions.

The Agilent 81480A and 81680A/40A/82A/42A Tunable Laser modules are equipped with PMF outputs as standard.

For the Agilent 81689A Tunable Laser module, PMF output is available as an option.

E

Connector Key

Fiber Cladding

H

Fiber Core

Stress Rods

(8- m Diameter)

Slow Axis (Polarization Axis)

Not to Scale

Figure 11 PMF Output Connector

Angled and Straight Contact Connectors

Angled contact connectors help you to control return loss. With angled fiber endfaces, reflected light tends to reflect into the cladding, reducing the amount of light that reflects back to the source.

The Agilent 81480 and 81680A/40A/82A/42A/89A Tunable Laser modules can have the following connector interface options:

•Option 071, Polarization-maintaining fiber straight contact connectors, or

•Option 072, Polarization-maintaining fiber angled contact connectors.

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Getting Started with Tunable Laser Sources

Optical Output

Two additional connector interface options are available for the

Agilent 81689A Tunable Laser module:

• Option 021, Standard single-mode fiber straight contact connectors,

or

	• Option 022, Standard single-mode fiber angled contact connectors.
C A U TI O N	If the contact connector on your instrument is angled, you can only
	use cables with angled connectors with the instrument.

Angled Contact	Straight Contact
Connector Symbol	Connector Symbol

Figure 12 Angled and Straight Contact Connector Symbols

Figure 12 shows the symbols that tell you whether the contact connector of your Tunable Laser module is angled or straight. The angled contact connector symbol is colored green.

Figure 7 and Figure 13 show the front panel of the Agilent 81682A Tunable Laser module with straight and angled contact connectors respectively.

You should connect straight contact fiber end connectors with neutral sleeves to straight contact connectors and connect angled contact fiber end connectors with green sleeves to angled contact connectors.

N O TE You cannot connect angled non-contact fiber end connectors with orange sleeves directly to the instrument.

Figure 13 Agilent 81682A Tunable Laser Module (angled contact connector)

See “Accessories” on page 31 for further details on connector interfaces and accessories.

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Signal Input and Output

Getting Started with Tunable Laser Sources

Signal Input and Output

CA U TI O N	There are two BNC connectors on the front panel of the
	Agilent 81480A, Agilent 81680A, Agilent 81680A, Agilent 81640A,
	Agilent 81682A, and Agilent 81642A - a BNC input connector and a
	BNC output connector.
	There is one BNC connector on the front panel of the Agilent 81689A -
	a BNC input connector.
	An absolute maximum of ±6 V can be applied as an external voltage to
	any BNC connector.

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Getting Started with Tunable Laser Sources

Signal Input and Output

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