Tektronix System 25 Laser Diode Test System Quick Start Guide

System 25

Laser Diode Test System

Quick Setup Guide

A GREATER MEASURE OF CONFIDENCE

WARRANTY

Keithley Instruments, Inc. warrants this product to be free from defects in material and workmanship for a
period of 1 year from date of shipment.

Keithley Instruments, Inc. warrants the following items for 90 days from the date of shipment: probes, cables,
rechargeable batteries, diskettes, and documentation.

During the warranty period, we will, at our option, either repair or replace any product that proves to be defective.

To exercise this warranty, write or call your local Keithley representative, or contact Keithley headquarters in
Cleveland, Ohio. You will be given prompt assistance and return instructions. Send the product, transportation
prepaid, to the indicated service facility. Repairs will be made and the product returned, transportation prepaid.
Repaired or replaced products are warranted for the balance of the original warranty period, or at least 90 days.

LIMITATION OF WARRANTY

This warranty does not apply to defects resulting from product modification without Keithley’s express written
consent, or misuse of any product or part. This warranty also does not apply to fuses, software, non-rechargeable
batteries, damage from battery leakage, or problems arising from normal wear or failure to follow instructions.

THIS WARRANTY IS IN LIEU OF ALL OTHER WARRANTIES, EXPRESSED OR IMPLIED, INCLUD­ING ANY IMPLIED WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR USE.
THE REMEDIES PROVIDED HEREIN ARE BUYER’S SOLE AND EXCLUSIVE REMEDIES.

NEITHER KEITHLEY INSTRUMENTS, INC. NOR ANY OF ITS EMPLOYEES SHALL BE LIABLE FOR
ANY DIRECT, INDIRECT, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF
THE USE OF ITS INSTRUMENTS AND SOFTWARE EVEN IF KEITHLEY INSTRUMENTS, INC., HAS
BEEN ADVISED IN ADVANCE OF THE POSSIBILITY OF SUCH DAMAGES. SUCH EXCLUDED DAM­AGES SHALL INCLUDE, BUT ARE NOT LIMITED TO: COSTS OF REMOVAL AND INSTALLATION,
LOSSES SUSTAINED AS THE RESULT OF INJURY TO ANY PERSON, OR DAMAGE TO PROPERTY.

Keithley Instruments, Inc.

Sales Offices: BELGIUM: Bergensesteenweg 709 • B-1600 Sint-Pieters-Leeuw • 02-363 00 40 • Fax: [phone]

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28775 Aurora Road • Cleveland, Ohio 44139 • 440-248-0400 • Fax: [phone]

1-888-KEITHLEY (534-8453) • www.keithley.com

1/03

System 25

Laser Diode Test System

Quick Setup Guide

©2001, Keithley Instruments, Inc.

All rights reserved.

Cleveland, Ohio, U.S.A.

Second Printing, April 2003

Document Number: LIV-903-01 Rev. B

Manual Print History

The print history shown below lists the printing dates of all Revisions and Addenda created
for this manual. The Revision Level letter increases alphabetically as the manual undergoes sub­sequent updates. Addenda, which are released between Revisions, contain important change in­formation that the user should incorporate immediately into the manual. Addenda are numbered
sequentially. When a new Revision is created, all Addenda associated with the previous Revision
of the manual are incorporated into the new Revision of the manual. Each new Revision includes
a revised copy of this print history page.

Revision A (Document Number LIV-903-01).................................................................. June 2001

Revision B (Document Number LIV-903-01) ................................................................. April 2003

All Keithley product names are trademarks or registered trademarks of Keithley Instruments, Inc.
Other brand names are trademarks or registered trademarks of their respective holders.

S

afety Precautions

The following safety precautions should be observed before using this product and any associated instrumentation. Although
some instruments and accessories would normally be used with non-hazardous voltages, there are situations where hazardous
conditions may be present.

This product is intended for use by qualified personnel who recognize shock hazards and are familiar with the safety precautions
required to avoid possible injury. Read and follow all installation, operation, and maintenance information carefully before us­ing the product. Refer to the manual for complete product specifications.

If the product is used in a manner not specified, the protection provided by the product may be impaired.

The types of product users are:

Responsible body

ment is operated within its specifications and operating limits, and for ensuring that operators are adequately trained.

Operators

instrument. They must be protected from electric shock and contact with hazardous live circuits.

Maintenance personnel

voltage or replacing consumable materials. Maintenance procedures are described in the manual. The procedures explicitly state
if the operator may perform them. Otherwise, they should be performed only by service personnel.

Service personnel

trained service personnel may perform installation and service procedures.

Keithley products are designed for use with electrical signals that are rated Installation Category I and Installation Category II,
as described in the International Electrotechnical Commission (IEC) Standard IEC 60664. Most measurement, control, and data
I/O signals are Installation Category I and must not be directly connected to mains voltage or to voltage sources with high tran­sient over-voltages. Installation Category II connections require protection for high transient over-voltages often associated with
local AC mains connections. Assume all measurement, control, and data I/O connections are for connection to Category I sourc­es unless otherwise marked or described in the Manual.

Exercise extreme caution when a shock hazard is present. Lethal voltage may be present on cable connector jacks or test fixtures.
The American National Standards Institute (ANSI) states that a shock hazard exists when voltage levels greater than 30V RMS,

42.4V peak, or 60VDC are present.

circuit before measuring.

Operators of this product must be protected from electric shock at all times. The responsible body must ensure that operators
are prevented access and/or insulated from every connection point. In some cases, connections must be exposed to potential
human contact. Product operators in these circumstances must be trained to protect themselves from the risk of electric shock.
If the circuit is capable of operating at or above 1000 volts,

Do not connect switching cards directly to unlimited power circuits. They are intended to be used with impedance limited sourc­es. NEVER connect switching cards directly to AC mains. When connecting sources to switching cards, install protective de­vices to limit fault current and voltage to the card.

Before operating an instrument, make sure the line cord is connected to a properly grounded power receptacle. Inspect the con­necting cables, test leads, and jumpers for possible wear, cracks, or breaks before each use.

When installing equipment where access to the main power cord is restricted, such as rack mounting, a separate main input pow­er disconnect device must be provided, in close proximity to the equipment and within easy reach of the operator.

For maximum safety, do not touch the product, test cables, or any other instruments while power is applied to the circuit under
test. ALWAYS remove power from the entire test system and discharge any capacitors before: connecting or disconnecting ca-

is the individual or group responsible for the use and maintenance of equipment, for ensuring that the equip-

use the product for its intended function. They must be trained in electrical safety procedures and proper use of the

perform routine procedures on the product to keep it operating properly, for example, setting the line

are trained to work on live circuits, and perform safe installations and repairs of products. Only properly

A good safety practice is to expect that hazardous voltage is present in any unknown

no conductive part of the circuit may be exposed.

5/02

bles or jumpers, installing or removing switching cards, or making internal changes, such as installing or removing jumpers.

Do not touch any object that could provide a current path to the common side of the circuit under test or power line (earth) ground. Al­ways make measurements with dry hands while standing on a dry, insulated surface capable of withstanding the voltage being measured.

The instrument and accessories must be used in accordance with its specifications and operating instructions or the safety of the
equipment may be impaired.

Do not exceed the maximum signal levels of the instruments and accessories, as defined in the specifications and operating in­formation, and as shown on the instrument or test fixture panels, or switching card.

When fuses are used in a product, replace with same type and rating for continued protection against fire hazard.

Chassis connections must only be used as shield connections for measuring circuits, NOT as safety earth ground connections.

If you are using a test fixture, keep the lid closed while power is applied to the device under test. Safe operation requires the use
of a lid interlock.

If or is present, connect it to safety earth ground using the wire recommended in the user documentation.

!

The symbol on an instrument indicates that the user should refer to the operating instructions located in the manual.

The symbol on an instrument shows that it can source or measure 1000 volts or more, including the combined effect of
normal and common mode voltages. Use standard safety precautions to avoid personal contact with these voltages.

The

WARNING

information very carefully before performing the indicated procedure.

The

CAUTION

ranty.

Instrumentation and accessories shall not be connected to humans.

Before performing any maintenance, disconnect the line cord and all test cables.

To maintain protection from electric shock and fire, replacement components in mains circuits, including the power transformer,
test leads, and input jacks, must be purchased from Keithley Instruments. Standard fuses, with applicable national safety ap­provals, may be used if the rating and type are the same. Other components that are not safety related may be purchased from
other suppliers as long as they are equivalent to the original component. (Note that selected parts should be purchased only
through Keithley Instruments to maintain accuracy and functionality of the product.) If you are unsure about the applicability
of a replacement component, call a Keithley Instruments office for information.

To clean an instrument, use a damp cloth or mild, water based cleaner. Clean the exterior of the instrument only. Do not apply
cleaner directly to the instrument or allow liquids to enter or spill on the instrument. Products that consist of a circuit board with
no case or chassis (e.g., data acquisition board for installation into a computer) should never require cleaning if handled accord­ing to instructions. If the board becomes contaminated and operation is affected, the board should be returned to the factory for
proper cleaning/servicing.

heading in a manual explains dangers that might result in personal injury or death. Always read the associated

heading in a manual explains hazards that could damage the instrument. Such damage may invalidate the war-

Table of Contents

Introduction ................................................................................... 1

Standard system configurations .................................................... 1

Model s25-01000: General Purpose Laser Diode

Model s25-21230: Transmitter Module ................................. 2

Model s25-21210: 980nm Pump Module .............................. 2

Model s25-41220: High Power Pump Module ...................... 2

System block diagram ................................................................... 3

Installation ..................................................................................... 4

Connections ................................................................................... 6

Signal connections ................................................................. 6

Control connections ............................................................... 8

Power line connections .......................................................... 9

Power-up and checkout ................................................................. 9

Power-up ................................................................................ 9

Laser diode test resistor network ........................................... 9

Checkout procedure ............................................................. 10

Instrument programming ............................................................. 10

Model 2400/2420/2440 SourceMeter programming ........... 10

Model 2500 Dual Photodiode Meter programming ............. 12

Model 2510 TEC SourceMeter programming ..................... 14

Test Measurement .............................................................. 1

List of Illustrations

Figure 1 System block diagram ............................................................... 3

Figure 2 Suggested rack mount locations ............................................... 5

Figure 3 System signal connections ........................................................ 7

Figure 4 System control connections ...................................................... 8

Figure 5 Test resistor network ................................................................. 9

Congratulations!

Congratulations on your purchase of Keithley’s System 25 Laser Diode Test System for
testing of Laser Diode Modules (LDMs). In applications such as yours, our Laser Diode
Test System has been proven to provide a complete LDM test solution, including control
of the thermo-electric cooler (TEC), which is a critical part of LDM assemblies.

In this quick setup guide, you will find information that will enable you to:

• configure

• install

• make signal connections

• perform power-up and checkout

• begin programming

The rest of this section provides an overview of our Laser Diode Test System.

Your system is either a custom configuration or one of the following standard
configurations:

• s25-01000 General Purpose Laser Diode Test System (previously LIV part number LIV-1)

• s25-21230 T ransmitter Module Laser Diode Test System (previously LIV part number LIV-2)

• s25-21210 980nm Pump Laser Diode Test System (previously LIV part number LIV-3)

• s25-41220 High Power Pump Module Laser Diode Test System (previously LIV part

number LIV -4)

• s25-02000 General Purpose Laser Diode Test System with Fixture TEC Control (pre viously

LIV part number LIV -1-F)

• s25-22230 T ransmitter Module Laser Diode T est System with Fixture TEC Control (pre viously

LIV part number LIV -2-F)

• s25-22210 980nm Pump Laser Diode Test System with Fixture TEC Control (previously LIV

part number LIV-3-F)

• s25-42220 High Power Pump Module Laser Diode Test System with Fixture TEC Control

(previously LIV part number LIV-4-F)

The basic configuration can be easily modified to allow for new connections or expansion
with new measurement and control functions, such as other Keithley meters and switching
systems. A demonstration software package, created in V isual Basic, provides you with a
head start in programming your specific laser diode test system application.

These configurations may include some or all of the following instruments:

• Model 2400 SourceMeter® that drives the laser diode and acts as a modulator bias source in
LDMs employing an integrated modulator .

• Model 2440 5A SourceMeter Instrument that provides a 5A source and measure capability that
makes it well suited for testing high power pump lasers.

• Model 2500 Dual Photodiode Meter that uses a time-saving dual-channel design to facilitate
simultaneous measurement of related parameters.

• Model 2500INT Integrating Sphere that allows the system to make direct measurements of
optical power, with results expressed in watts.

• The Model 2510 TEC Sourcemeter that combines high-speed DC sourcing and measurement
with the ability to control the operation of a laser diode module’s Thermo-Electric Cooler or
TEC (also known as a “Peltier device”).

• Model 2510-AT Autotuning TEC SourceMeter that adds autotuning capability using a modified
Zeigler-Nichols algorithm. This allo ws you to determine P, I, and D (proportional, integral, and
derivative) values for closed loop temperature control so you no longer need to determine the
optimal values for these coefficients e xperimentally .

Optoelectronic Solutions from Keithley

Keithley offers a suite of products for electrical production test applications that support
your need for accuracy and throughput. Other optoelectronic solutions available from
Keithley include:

• Model 2520 Pulsed Laser Diode Test System that combines high speed current pulsing with
measurement capabilities for precision testing at earlier stages of production without the
damaging effects of device heating.

• The Model 4200 Semiconductor Characterization System that combines high resolution DC
source and measurement with real-time plotting and analysis for material and device character­ization and development.

• Keithle y’ s RF/Micro wa ve Signal Routing Systems for switching and conditioning of high data
rate signals up to 40GHz.

Laser Diode Test System

Quick Setup Guide

Introduction

This guide provides basic information on setting up and using the System 25 Laser Diode
Test System, which combines all the necessary DC measurement capabilities to test laser diode
modules. For more detailed information on each of the instruments in the Laser Diode Test
System, refer to the corresponding user’s manual supplied with each unit.

Standard system configurations

The standard system configurations below are supplied with all the cables and adapters
required for communication, triggering, and connection to the device to be tested. Also
included is all the necessary hardware for rack mounting the instruments.

System 25

Model s25-01000: General Purpose Laser Diode Test Measurement

This system is configured as a general purpose system. The system includes:

• Model 2400 SourceMeter

• Model 2500 Dual Photodiode Meter
facet photo current.

• Model 2510 TEC SourceMeter



for laser drive and forward voltage measure.



for back facet detector measurement and front



for temperature control of the internal TEC module.

2 System 25 Laser Diode Test System Quick Setup Guide

Model s25-21230: Transmitter Module

This system is configured specifically for testing of transmitter laser module in the 1330nm

to 1550nm range. The system includes:

• Model 2420 SourceMeter for laser drive and forward voltage measure.

• Model 2500 Dual Photodiode Meter for back facet detector measurement and front
facet optical power.

• Model 2510-AT Autotuning TEC SourceMeter for temperature control of the internal
TEC module.

• Model 2500INT Integrating Sphere with a cooled InGaAs detector and an FC/PC input
connector for optical power measurement.

Model s25-21210: 980nm Pump Module

This system is configured specifically for testing of 980nm pump laser with an input current

level of 3A or less. The system includes:

• Model 2420 SourceMeter for laser drive up to 3A and forward voltage measure.

• Model 2500 Dual Photodiode Meter for back facet detector measurement and front
facet optical power.

• Model 2510-AT Autotuning TEC SourceMeter for temperature control of the internal
TEC module.

• Model 2500INT Integrating Sphere with a silicon detector and an FC/PC input connec­tor for optical power measurement.

Model s25-41220: High Power Pump Module

This system is configured specifically for testing of high power pump laser module with a

14xx wavelength. The system includes:

• Model 2440 SourceMeter for laser drive up to 5A and forward voltage measure.

• Model 2500 Dual Photodiode Meter for back facet detector measurement and front
facet optical power.

• Model 2510-AT Autotuning TEC SourceMeter for temperature control of the internal
TEC module.

• Model 2500INT Integrating Sphere with a germanium detector and an FC/PC input
connector optical power measurement.

System block diagram

Figure 1 shows an overall block diagram of the Laser Diode Test System. Components

include:

• Model 2400/2420/2440 SourceMeter: sources current to the laser diode module and
measures voltage across the device.

• Model 2500 Dual Photodiode Meter: Biases and measures currents from the two photo­diode detectors.

• Model 2510/2510-AT TEC SourceMeter: Controls the TEC (thermo-electric cooler)
power to maintain the laser diode module at the desired temperature.

• Model 2500INT Integrating Sphere: Provides optimal coupling of light from laser
diode module to integral Ge, Si, or InGaAs photodiode detector (not included in
Model LIV-1).

• Trigger Link: synchronizes instrument readings.

• GPIB: interfaces the instruments to the controlling computer.

Figure 1

System block diagram

System 25 Laser Diode Test System Quick Setup Guide 3

GPIB

Trigger Link

2510/

2510-AT

Thermistor

Laser

GPIB GPIB

Diode

2400/2420/

2440

GPIB

LDM*

TEC

2500

Fiber

Computer

2500INT

*LDM (Laser Diode Module) = Device Under Test

4 System 25 Laser Diode Test System Quick Setup Guide

Installation

The instruments for the Laser Diode Test System are shipped configured for bench-top use.
If system rack mounting is desired, the necessary rack mounting kits are provided. Follow the
steps below to rack mount the instruments.

NOTE

See the documentation provided with the supplied Model 4288-1 and 4288-2 rack
mount kits for more detailed information on attaching rack mount hardware.

1. First determine the desired location of each instrument. Figure 2 shows suggested
mounting locations. Be sure to allow sufficient air space above and below the instru­ments, as shown, for proper ventilation.

2. Remove the handles and feet from the instruments, then attach the necessary rack
mounting hardware.

3. Slide the instruments into the rack, then secure them with four mounting screws.

Figure 2

Suggested rack mount locations

System 25 Laser Diode Test System Quick Setup Guide 5

1U (1.75”)

Air Space

Model 2400,

2420, or 2440

SourceMeter

1U (1.75”)

Air Space

DISPLAY

POWER

DISPLAY

TOGGLE/
LOCAL

POWER

4-WIRE

INPUT/

SENSE

OUTPUT

HI

250V

250V

5V

PEAK

PEAK

MEAS

EDIT

TOGGLE

V

LOCAL

67

DIGITS SPEED

FCTN

I

Ω

V

1

230

4

TRIG

REL

LIMIT

FILTER

+/-

89

RECALL

STORE

CONFIG MENU

SourceMeter

SOURCE

I

RANGE

5

EDIT

EXIT ENTER

AUTO

RANGE

SWEEP

PEAK

LO

250V
PEAK

CHANNEL
SELECT

MSR1

DISPLAY

016723

TOGGLE

TERMINALS

ON/OFF

FRONT/
REAR

OUTPUT

POWER

LOCAL

DIGITS SPEED

I

MENU

CONFIG

EDIT

EXIT ENTER

2500 DUAL PHOTODIODE METER

RATIO

SRC1 SRC2

DELTA

MSR2

LIMIT

REL

FILTER

8

STORE RECALL

TRIG

945+/- 0000

CONFIG

EDIT

SWEEP

MENU

EXIT ENTER

ON/OFF

OUTPUT

RANGE

AUTO

ON/OFF

RANGE

OUTPUT

®

2510 TEC SourceMeter

V

R

T

Model 2510/
2510-AT TEC
SourceMeter

Model 2500
Dual
Photodiode
Meter

6 System 25 Laser Diode Test System Quick Setup Guide

Connections

Signal connections

Using Figure 3 as a guide, make signal connections as follows:

•

Model 2400/2420/2440 SourceMeter

SENSE HI and LO terminals to the laser diode module using the supplied banana-to­coaxial adapters and BNC-to-alligator cables as shown. The instrument must be used in
the 4-wire sense mode.

•

Model 2500 Dual Photodiode Meter

diodes and/or integrating sphere using the supplied triax cables as shown. Connect the
triax center conductor to the detector terminal labeled anode; triax outer shield (chassis
ground) to the detector terminal labeled cathode. For the Model 2500INT integrating
sphere, make direct connections using a triax cable and Model 6172 adapter. Note:
ground connect mode must be enabled to use this configuration. (When using the demo
software, channel 1 is the front facet, and channel 2 is the back facet.)

•

Model 2510/2510-AT TEC SourceMeter

nals to the TEC and temperature sensor using the supplied Model 2510-CAB cable as
shown.

— Connect the rear panel INPUT/OUTPUT and

— Connect the INPUT jacks to the two photo-

— Connect the INPUT and OUTPUT termi-

NOTE

Additional cable configurations are available from Keithley Instruments, Inc. for
other connections to the DUT. Contact your local sales representative for details.

Figure 3

WARNING:NO INTERNAL OPERATOR SERVICABLE PARTS,SERVICE BY QUALIFIED PERSONNEL ONLY.

CAUTION:FOR CONTINUED PROTECTION AGAINST FIRE HAZARD,REPLACE FUSE WITH SAME TYPE AND RATING.

CAUTION:FOR CONTINUED PROTECTION AGAINST FIRE HAZARD,REPLACE FUSE WITH SAME TYPE AND RATING.

CAUTION:FOR CONTINUED PROTECTION AGAINST FIRE HAZARD,REPLACE FUSE WITH SAME TYPE AND RATING.

WARNING:NO INTERNAL OPERATOR SERVICABLE PARTS,SERVICE BY QUALIFIED PERSONNEL ONLY.

WARNING:NO INTERNAL OPERATOR SERVICABLE PARTS,SERVICE BY QUALIFIED PERSONNEL ONLY.

CAUTION:FOR CONTINUED PROTECTION AGAINST FIRE HAZARD,REPLACE FUSE WITH SAME TYPE AND RATING.

System signal connections

INPUT/OUTPUT

Connector

2510-CAB

Cable

Model 2510/2510-AT

TEC SourceMeter

CAT I

!

OUTPUT INPUT

F+ S+ S- F- F+ F- S+ S-

ISOLATION FROM EARTH: 30V MAX.

MADE IN

U.S.A.

ENABLE-DIG I/O

RS-232

TRIGGER

LINK

LINE FUSE

SLOWBLOW

2.5A, 250V

!

LINE RATING

100-240VAC

50, 60 HZ

90VA MAX

-+ +

WITH FRONT PANEL MENU)

120

-

System 25 Laser Diode Test System Quick Setup Guide 7

2510-CAB Connections

(Assumes + Current Cools TEC)

IEEE-488

(ENTER IEEE ADDRESS

Terminal Wire Color
Thermistor -

Thermistor +
Thermistor ­Thermistor +
TEC+
TEC+
TEC­TEC-

White
Blue
Yellow
Red
Black
Green
Brown
Orange

Center Conductor

(Anode)

BNC

Cables

HI

125V

5V

PEAK

PEAK

LO

4-WIRE

!

SENSE

OUTPUT

IEEE-488

(ENTER IEEE ADDRESS

WITH FRONT PANEL MENU)

SENSE LO

Thermistor TEC

Laser
Diode

LDM

Center

Conductors

SENSE HI

INPUT/
OUTPUT HI

INPUT/

OUTPUT LO

5V
PK

V, Ω,

GUARD

5V

125V

PEAK

PEAK

GUARD
SENSE

INPUT/

250V
PEAK

MADE IN

U.S.A.

SLOWBLOW

LINE RATING

TRIGGER

LINK

RS232

Model 2400/2420/2440

SourceMeter

Model 2500INT

Integrating Sphere

LINE FUSE

3.15A, 250V

100-240VAC

50, 60HZ

220VA MAX

INTERLOCK-

DIGITAL I/O

Fiber

6172

Adapter

Outer Shield

(Cathode)

Triax
Cables

INPUT

INPUT

CHANNEL 1

VOLTAGE SOURCE

OUTPUT CHANNEL 1

Note: Enable Ground

RATINGS MAX
100V @ 20mA

COMMON

RATINGS MAX
100V @ 20mA

MODE
200V

CHANNEL 2

!

CAT I

VOLTAGE SOURCE

OUTPUT CHANNEL 2

MADE IN
U.S.A.

INPUT

TRIGGER LINK

DIGITAL I/O

RS-232

LINE RATING

50, 60Hz

60 VA MAX

FUSE LINE

630 mAT

100 VAC

(SB)

120 VAC

!

315 mAT

220 VAC

(SB)

240 VAC

Model 2500

Dual Photodiode Meter

Connect Mode

IEEE-488

(CHANGE IEEE ADDRESS

WITH FRONT PANEL MENU)

120

8 System 25 Laser Diode Test System Quick Setup Guide

WARNING:NO INTERNAL OPERATOR SERVICABLE PARTS,SERVICE BY QUALIFIED PERSONNEL ONLY.

CAUTION:FOR CONTINUED PROTECTION AGAINST FIRE HAZARD,REPLACE FUSE WITH SAME TYPE AND RATING.

CAUTION:FOR CONTINUED PROTECTION AGAINST FIRE HAZARD,REPLACE FUSE WITH SAME TYPE AND RATING.

CAUTION:FOR CONTINUED PROTECTION AGAINST FIRE HAZARD,REPLACE FUSE WITH SAME TYPE AND RATING.

WARNING:NO INTERNAL OPERATOR SERVICABLE PARTS,SERVICE BY QUALIFIED PERSONNEL ONLY.

WARNING:NO INTERNAL OPERATOR SERVICABLE PARTS,SERVICE BY QUALIFIED PERSONNEL ONLY.

CAUTION:FOR CONTINUED PROTECTION AGAINST FIRE HAZARD,REPLACE FUSE WITH SAME TYPE AND RATING.

Control connections

Refer to Figure 4 for the following control connections.

GPIB connections

Connect the rear panel IEEE-488 connectors of each instrument to the IEEE-488 interface of
the next instrument, and then to the computer interface using the supplied Model 7007 GPIB
cables.

Trigger link connections

Connect the rear panel TRIGGER LINK connectors of the Model 2400/2420/2440 and
Model 2500 together using the supplied Model 8501 trigger link cable.

Figure 4

System control connections

CAT I

!

OUTPUT INPUT

F+ S+ S- F- F+ F- S+ S-

ISOLATION FROM EARTH: 30V MAX.

Model 2500 Dual

Photodiode Meter

RATINGS MAX
100V @ 20mA

INPUT

CHANNEL 1

VOLTAGE SOURCE

OUTPUT CHANNEL 1

COMMON

RATINGS MAX
100V @ 20mA

MODE
200V

CHANNEL 2

!

CAT I

VOLTAGE SOURCE
OUTPUT CHANNEL 2

MADE IN

U.S.A.

INPUT

TRIGGER LINK

DIGITAL I/O

LINE RATING

50, 60Hz

60 VA MAX

FUSE LINE

630 mAT

(SB)

!

315 mAT

(SB)

IEEE-488

5V

HI

IEEE-488

(CHANGE IEEE ADDRESS

WITH FRONT PANEL MENU)

RS-232

120

100 VAC
120 VAC

220 VAC
240 VAC

125V
PEAK

5V

PEAK

LO

4-WIRE

!

SENSE

IEEE-488

(ENTER IEEE ADDRESS

WITH FRONT PANEL MENU)

INPUT/

OUTPUT

PK

5V

125V

PEAK

PEAK

250V

PEAK

MADE IN

U.S.A.

TRIGGER

V, Ω,

GUARD

GUARD
SENSE

IEEE-488

(ENTER IEEE ADDRESS

TRIGGER

LINK

WITH FRONT PANEL MENU)

Model 2510/

2510-AT

120

MADE IN

U.S.A.

LINE FUSE

SLOWBLOW

3.15A, 250V

LINE RATING

100-240VAC

50, 60HZ

220VA MAX

INTERLOCK­DIGITAL I/O

TEC SourceMeter

Model 2400/

2420/2440

SourceMeter

ENABLE-DIG I/O

RS-232

LINK

LINE FUSE

SLOWBLOW

2.5A, 250V

!

LINE RATING

100-240VAC

50, 60 HZ
90VA MAX

RS232

TRIGGER

LINK

PC Computer

Model 8501 Trigger

Link Cable

IEEE-488
Interface

TRIGGER

LINK

Model 7007

GPIB Cables

Power line connections

Connect instrument power line inputs to a grounded power outlet using the supplied line
cords. Make certain that the power line voltage is within the range specified on the rear panel of
each instrument.

Power-up and checkout

Power-up

Turn on the power to all instruments, and verify that they all go through their normal power­up cycles. Note the IEEE-488 address that is shown on the bottom line of the display as part of
the power-up cycle, for example: SCPI Addr = 25. Be sure to use that address in your program,
or change the addresses to the desired settings. (Use the COMMUNICATION/GPIB selection
in the main MENU.)

Laser diode test resistor network

Figure 5 shows a schematic diagram of a resistive network that can be used to check out
your system. These resistors can be mounted in a shielded component box that is equipped with
banana jacks for connections to 2400/2420/2440 INPUT/OUTPUT HI and LO, as well as two
triax jacks for connections to the two Model 2500 INPUT jacks.

System 25 Laser Diode Test System Quick Setup Guide 9

Figure 5

Test resistor network

Model 2400/2420/2440

SourceMeter

INPUT/OUTPUT HI

INPUT/OUTPUT LO

Shielded

Component Box

5kΩ

100Ω

1kΩ

Model 2500

Dual Photodiode Meter

Channel 2

Triax INPUT

Channel 1

Triax INPUT

10 System 25 Laser Diode Test System Quick Setup Guide

Checkout procedure

Instruments can be checked for proper operation using the resistor network in Figure 5 as

follows:

• Model 2400/2420/2440: Select SOURCE I, MEASURE V, then set the source current to
+50mA. Turn on the output, then verify that the measured voltage is approximately +5V.

• Model 2500: Set the Model 2400/2420/2440 for SOURCE V, then set the output volt­age to +5V. Turn on the output, then verify that the displayed Model 2500 channel 1
reading is approximately +5mA, and the displayed Model 2500 channel 2 reading is
about +1mA.

Instrument programming

Several demonstration applications are provided on the software disk supplied with your
Laser Diode Test System. Included is a Labview application and several Visual Basic (VB)
applications specific to the type of interface card. These programs are fully functional and can
be easily modified for your specific purposes.

The following section provides details regarding the function of one of the VB applications
provided. This information will aid your modification effort to taylor the applications to your
specific needs.

Model 2400/2420/2440 SourceMeter programming

The code fragment below is a subroutine that sets up the SourceMeter for a laser diode current
sweep while measuring laser diode voltage. Various operating modes are programmed as follows:

• Beeper: off

• Auto zero: off for maximum speed

• Remote sensing: on (4-wire connections)

• Terminals: rear

• Source function: current

• Start current: set during program execution (10mA minimum)

• Stop current: set during program execution (1A maximum)

• Step current: set during program execution ([start - step]/10 minimum)

• Current source mode: linear sweep, best fixed source range

• Source delay and NPLCs: set during program execution

• Sense function: concurrent functions disabled, voltage function enabled

• Voltage limit: 5V

• Voltage measurement range: 20V

• Data elements: both voltage and current, binary format

• SRQ: generate SRQ when buffer is full

• Arm source and count: immediate source, infinite count (bypass arm layer)

• Trigger source and lines: trigger link, line 1 input, line 2 output

• Source trigger: wait for input trigger before changing source, bypass first trigger

• Trigger output: output trigger after delay phase of SDM cycle

• Trigger delay: 0ms

System 25 Laser Diode Test System Quick Setup Guide 11

Private Sub Setup24x0()

'Setup SourceMeter(tm) system commands:

Call send(intKth24x0, ":syst:beep:stat off", intStatus) 'disable beeper
Call send(intKth24x0, ":syst:azer:stat off", intStatus) 'disable auto zero for speed
Call send(intKth24x0, ":syst:rsen 1", intStatus) 'enable four-wire measurements

'Call send(intKth24x0, ":display:enable off", intStatus) 'disable display

Call send(intKth24x0, ":rout:term rear", intStatus) 'use rear terminals

'The source is configured for the sweep from textStartCurrent to textStopCurrent
'in steps defined by textStepCurrent. The sweep will use the best fixed range
'to prevent the inherent dicontinuities of range changing from being seen by the
'analysis code as kink. The source delay is also set to accommodate the cable and
'DUT capacitive loading.

Call send(intKth24x0, ":sour:func curr", intStatus) ’source current
Call send(intKth24x0, ":sour:curr:start " & textStartCurrent, intStatus) 'set start (min.)
Call send(intKth24x0, ":sour:curr:stop " & textStopCurrent, intStatus) 'set stop (max.)
Call send(intKth24x0, ":sour:curr:step " & textStepCurrent, intStatus) 'set step
Call send(intKth24x0, ":sour:curr:mode sweep", intStatus) 'enable sweep mode
Call send(intKth24x0, ":sour:swe:rang best", intStatus) 'use best fixed range
Call send(intKth24x0, ":sour:swe:spac lin", intStatus) 'select linear sweep
Call send(intKth24x0, ":sour:del " & txtSourceDelay, intStatus) 'set source delay

'The 24x0 will source current and measure the forward junction voltage
'across the laser diode. Both current and voltage will be passed to
'the analysis portion of the code.

Call send(intKth24x0, ":sens:volt:nplc " & comboNPLC, intStatus) 'set NPLC per input param.
Call send(intKth24x0, ":sens:func:conc off", intStatus) 'turn off concurrent meas.
Call send(intKth24x0, ":sens:func 'volt'", intStatus) 'sense voltage (V forward of LD)
Call send(intKth24x0, ":sens:volt:prot 5", intStatus) 'limit output voltage to 5V
Call send(intKth24x0, ":sens:volt:range 20", intStatus)

Call send(intKth24x0, ":form:elem volt,curr", intStatus) 'read both voltage and current

Call send(intKth24x0, ":format:data sre;bord swap", intStatus) 'binary format

Call send(intKth24x0, ":stat:meas:enab 512", intStatus) 'mask "buffer full" byte
Call send(intKth24x0, "*sre 1", intStatus) 'mask "measurement summary bit" for SRQ

'Trigger layer is used to keep track of triggers from the front facet
'photodetector meter. The trigger count will be set later.
Call send(intKth24x0, ":arm:sour imm", intStatus) 'bypass arm layer
Call send(intKth24x0, ":arm:count inf", intStatus)

Call send(intKth24x0, ":trig:clear", intStatus) 'clear triggers
Call send(intKth24x0, ":trig:sour tlink", intStatus) 'use trigger link
Call send(intKth24x0, ":trig:ilin 1", intStatus) 'input trigger on line 1
Call send(intKth24x0, ":trig:olin 2", intStatus) 'output trigger on line 2
Call send(intKth24x0, ":trig:input source", intStatus) 'wait for input trigger before

Call send(intKth24x0, ":trig:outp del", intStatus) 'output trigger after soaking device

Call send(intKth24x0, ":trig:dir source", intStatus) 'bypass first input trigger
Call send(intKth24x0, ":trig:delay 0", intStatus) 'set trigger delay to 0mS

End Sub

'changing source

'new source current value

12 System 25 Laser Diode Test System Quick Setup Guide

Model 2500 Dual Photodiode Meter programming

The code fragment below is a subroutine that sets up the Model 2500 to measure current
from both photodiodes using the 20mA range on both channels. Operating modes are set as
follows:

• Data format: channel 1 and channel 2 current, binary format

• Channel 1 NPLCs: set during program execution (0.01 to 10)

• Channel 1 current range: 20mA (set during program execution)

• Channel 1 voltage bias source: 10V range, value checked and set during program
execution

• Channel 1 source delay: 0

• Channel 1 ground connect mode: enabled

• Channel 2 NPLCs: set during program execution (0.01 to 10)

• Channel 2 current range: 20mA (set during program execution)

• Channel 2 voltage bias source: 10V range, value checked and set during program
execution

• Channel 2 source delay: 0

• Channel 2 ground connect mode: enabled

• Arm source: immediate (bypass arm layer)

• Arm count: 1

• Arm direction: acceptor (wait for trigger event)

• Trigger source and lines: trigger link, line 1 output, line 2 input

• Trigger input: wait for trigger before measuring

• Output trigger: trigger after settling

• Trigger event bypass: do not bypass on first pass through trigger layer

• Data store format: channel 1 and channel 2 currents

System 25 Laser Diode Test System Quick Setup Guide 13

Private Sub Setup2500()

'General instrument configuration
Call send(intKth2500, ":form:elem curr1,curr2", intStatus) 'output only current readings
Call send(intKth2500, ":form:data sre;bord swap", intStatus) 'binary format
'Call send(intKth2500, ":syst:key 16", intStatus) 'toggle display to show both channels

' ******* Configure Channel 1 of 2500 **********

'Setup sense circuitry for 20mA range
Call send(intKth2500, ":sens1:curr:nplc " & comboNPLC, intStatus) 'set NPLC using input Param.
Call send(intKth2500, ":sens1:curr:rang " & textN1CurrRange, intStatus) '20mA range

'Setup source to bias the front facet photodiode.
Call send(intKth2500, ":sour1:volt:range 10", intStatus) 'set range to 10V
If textN1Bias > 10 Then: textN1Bias = 10
If textN1Bias < -10 Then: textN1Bias = -10
Call send(intKth2500, ":sour1:volt " & textN1Bias, intStatus) 'set bias output
Call send(intKth2500, ":sour1:delay 0", intStatus) 'set source delay to zero
Call send(intKth2500, ":sour1:gcon 1", intStatus) 'enable ground connect relay

' ******* Configure Channel 2 of 2500 **********

'Setup sense circuitry for 20mA range
Call send(intKth2500, ":sens2:curr:nplc " & comboNPLC, intStatus) 'set NPLC using input Param.
Call send(intKth2500, ":sens2:curr:rang " & textN2CurrRange, intStatus) '20mA range

'Setup source to bias the photodiode with 5V.
Call send(intKth2500, ":sour2:volt:range 10", intStatus) 'set range to 10V
If textN2Bias > 10 Then: textN2Bias = 10
If textN2Bias < -10 Then: textN2Bias = -10
Call send(intKth2500, ":sour2:volt " & textN2Bias, intStatus) 'set bias output
Call send(intKth2500, ":sour2:delay 0", intStatus) 'set source delay to zero
Call send(intKth2500, ":sour2:gcon 1", intStatus) 'enable ground connect relay

'Setup Trigger Model: Bypass both arm layers and use trigger
'layer to synch with trigger from 24x0.

Call send(intKth2500, ":arm:sour imm", intStatus) 'bypass arm layer 1
Call send(intKth2500, ":arm:coun 1", intStatus) 'set scan count
Call send(intKth2500, ":arm:dir acc", intStatus) 'wait for trigger event
Call send(intKth2500, ":trig:clear", intStatus) 'clear triggers
Call send(intKth2500, ":trig:sour tlink", intStatus) 'use trigger link
Call send(intKth2500, ":trig:ilin 2", intStatus) 'input trigger on line 2
Call send(intKth2500, ":trig:olin 1", intStatus) 'output trigger on line 1
Call send(intKth2500, ":trig:input sense", intStatus) 'wait for input trigger before
Call send(intKth2500, ":trig:outp sense", intStatus) 'output trigger after setting
Call send(intKth2500, ":trig:dir acceptor", intStatus) 'do not bypass on first pass

Call send(intKth2500, ":trac:feed calc3,calc4", intStatus)

End Sub

14 System 25 Laser Diode Test System Quick Setup Guide

Model 2510 TEC SourceMeter programming

The code fragment shown below is a subroutine that conditionally sets up the following

Model 2510 operating modes:

• Current protection limit: 1A

• Sensor type: thermistor

• Thermistor sensor current range: auto

• Thermistor sensor measurement range: 10k

• Temperature setpoint: set during program execution

Private Sub comboTempOnOff_Click()

If comboTempOnOff.Text = "ON" Then

Call send(intKth2510, "*rst", intStatus)
Call send(intKth2510, ":sens:curr:prot:lev 1.0", intStatus) ' 1A current limit
Call send(intKth2510, ":sens:temp:tran ther", intStatus) ' Thermistor sensor type
Call send(intKth2510, ":sens:temp:curr:auto on", intStatus) ' Auto sensor current range
Call send(intKth2510, ":sens:temp:ther:range 1e4", intStatus) ' 10k ohm sensor resistance range
Call send(intKth2510, ":sour:temp:spo " & comboTempSetPoint.Text, intStatus) ' Program setpoint
Call send(intKth2510, ":outp on", intStatus) ' Turn on output
Call send(intKth2510, ":meas:res:ac?", intStatus) ' Get TEC AC resistance
Call enter(strData, 100, intLength, intKth2510, intStatus)
txtTECRes.Text = strData
Call send(intKth2510, ":outp on", intStatus)

Else

Call send(intKth2510, "*rst", intStatus)

End If

End Sub

Ω

Specifications are subject to change without notice.

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Printed in the U.S.A.

2/03