ILX Lightwave LDC-3700C Series User Manual

User’s Guide

Laser Diode Controller

LDC-3700C Series

ILX Lightwave Corporation · 31950 Frontage Road · Bozeman, MT, U.S.A. 59715 · U.S. & Canada: 1-800-459-9459 · International Inquiries: 406-556-2481 · Fax [phone]

ilx.custhelp.com · www.ilxlightwave.com

70041001 April 2009

TABLE OF CONTENTS



TABLE OF CONTENTS

Safety Information and the Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ix

General Safety Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ix

Safety Marking Symbols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . x

Limitations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xi

Returning an Instrument . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xi

Claims for Shipping Damage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .xii

Comments, Suggestions, and Problems . . . . . . . . . . . . . . . . . . . . . . . . . . . xiii

Chapter 1 Introduction and Specifications

Product Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Initial Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Installing the LDC-3700C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Grounding Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

AC Line Power Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

USB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

GPIB Connector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

The GPIB Address . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Tilt-Foot Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Rack Mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Operating the LDC-3700C Laser Diode Controller . . . . . . . . . . . . . . . . . . . . . 3

How to Obtain Repair Services . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Laser Current Source Specifications
Temperature Controller Specifications

General LDC-3700C Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

1

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

1

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Available Options and Accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

04_09 LDC-3700C Series i



TABLE OF CONTENTS

Chapter 2 Operations

Applying Power to your LD Controller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

The Power On Sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

The Power On State . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

37x4C Series Default Configuration: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Connecting to the Laser Controller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Connecting the Laser Current Source . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Interlock Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Photodiode Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Setting the PD bias . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Grounding Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Connecting to the TE Controller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

TEC Grounding Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Operating from the Front Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

The Laser Controller Display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

Operating a Laser in Constant Current “I” Mode . . . . . . . . . . . . . . . . . . . . . 20

Set Up the Controller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

Set the Range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Select the Laser Display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Adjusting the Set Point . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Set Current Source Limit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Set Compliance Voltage Limit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Automatic Shutoff Conditions for Laser Output . . . . . . . . . . . . . . . . . . . . . 24

Operating a Laser in Constant Power Mode, P . . . . . . . . . . . . . . . . . . . . . . 24

Entering Photodiode Responsivity values . . . . . . . . . . . . . . . . . . . . . . . . . 24

LASER Error Indicators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

Operating the TE Controller from the Front Panel . . . . . . . . . . . . . . . . . . . . . 29

The TEC display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

Operating the Controller in Temperature Mode, T . . . . . . . . . . . . . . . . . . . . 29

Setting up the Temperature Controller . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

Temperature Controller Sensor Selection . . . . . . . . . . . . . . . . . . . . . . . . . 30

Setting Temperature Sensor Constants . . . . . . . . . . . . . . . . . . . . . . . . . . 31

Setting TE Control Loop Gain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

Setting Temperature Controller Limits . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

Adjusting the Temperature Set Point . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

Operating the Controller in Resistance (Sensor) Mode, R . . . . . . . . . . . . 35

Operating the Controller in Constant Current Mode, I

Automatic Shut Off Conditions for TEC Output . . . . . . . . . . . . . . . . . . . . . 35

TEC Error Indicators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

TE . . . . . . . . . . . . . . . . . . .35

Functions and Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37



ii LDC-3700C Series

Saving and Recalling from the Front Panel . . . . . . . . . . . . . . . . . . . . . . . . . 37

Using the Laser Compliance Voltage Adjustment . . . . . . . . . . . . . . . . . . . . 38

Using the LDC-3700C Controller’s Trigger Function . . . . . . . . . . . . . . . . . . 38

Modulating the Controller Laser Current Source . . . . . . . . . . . . . . . . . . . . . 39

Boosting the TE Controller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

Chapter 3 Remote Operation

TABLE OF CONTENTS

USB Operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

USB Driver Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

Basic GPIB Concepts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

Data and Interface Messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

Talkers, Listeners, and Controllers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

GPIB Cable Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

The GPIB Connector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

Reading the GPIB Address . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

Changing the GPIB Address . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

Changing Operation from Local to Remote . . . . . . . . . . . . . . . . . . . . . . . . . . 47

Command Syntax . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

Letters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

White Space . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

Terminators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

Command Separators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

Command Tree Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

Syntax Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51

IEEE488.2 Common Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53

LDC-3700C Commonly Used Commands . . . . . . . . . . . . . . . . . . . . . . . . . . 54

Status Reporting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55

Event and Condition Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55

Operation Complete Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56

Output Off Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58

Command Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61

Sequential/Overlapped Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61

Query Response Timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61

04_09 LDC-3700C Series iii



TABLE OF CONTENTS

Chapter 4 Command Reference

Remote Command Reference Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64

Command Reference . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69

Chapter 5 Calibration and Troubleshooting

Calibration Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135

Recommended Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136

Local Calibration of the LDC-3700C Temperature Controller . . . . . . . . . 139

Calibrating the Thermistor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139

AD590 Sensor Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 140

LM335 Sensor Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 140

ITE Current Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141

Local Calibration of the Laser Current Source . . . . . . . . . . . . . . . . . . . . . 142

Current Source Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142

I

Current Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144

PD

Laser Forward Voltage Measurement Calibration . . . . . . . . . . . . . . . . . . 146

Remote Calibration of the LDC-3700C Controller . . . . . . . . . . . . . . . . . . . 147

Thermistor Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147

AD590 Sensor Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148

LM335 Sensor Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148

I

Current Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149

TE

TEC Voltage Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150

Current Source Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 151

I

Current Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153

PD

Laser Forward Voltage Measurement Calibration . . . . . . . . . . . . . . . . . . 154

Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155

Error Messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157



iv LDC-3700C Series

LIST OF FIGURES



LIST OF FIGURES

Figure 1.1 LDC 3700C Series Controller Front View . . . . . . . . . . . . .4

Figure 1.2 LDC-3700C Rear Panel . . . . . . . . . . . . . . . . . . . . . . . . . .4

Figure 2.1 Laser Diode Connection Configurations . . . . . . . . . . . . .16

Figure 2.2 Back Panel LD Connector . . . . . . . . . . . . . . . . . . . . . . . .17

Figure 2.3 Rear Panel TEC Connector . . . . . . . . . . . . . . . . . . . . . . .19

Figure 2.4 LDC-3700C Series Rear Panel . . . . . . . . . . . . . . . . . . . .39

Figure 2.5 Rear Panel TEC Connector . . . . . . . . . . . . . . . . . . . . . . .41

Figure 3.1 GPIB Cable Connections . . . . . . . . . . . . . . . . . . . . . . . .45

Figure 3.2 GPIB Connector Diagram . . . . . . . . . . . . . . . . . . . . . . . .46

Figure 3.3 Command Path Structure . . . . . . . . . . . . . . . . . . . . . . . .51

Figure 3.4 Common Command Diagrams . . . . . . . . . . . . . . . . . . . .53

Figure 3.5 Status Reporting Scheme . . . . . . . . . . . . . . . . . . . . . . . .57

Figure 3.6 LASER Output Off Register . . . . . . . . . . . . . . . . . . . . . . .59

Figure 3.7 TEC Output Off Register . . . . . . . . . . . . . . . . . . . . . . . . .59

Figure 5.1 I

Calibration Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . .137

PD

04_09 LDC-3700C Series v



LIST OF FIGURES



vi LDC-3700C Series

LIST OF TABLES



LIST OF TABLES

Table 1.1 Options and Accessories . . . . . . . . . . . . . . . . . . . . . . . . . .11

Table 2.1 Laser Error Indicators. . . . . . . . . . . . . . . . . . . . . . . . . . . . .28

Table 2.2 SENSOR SELECT Switch Positions . . . . . . . . . . . . . . . . .31

Table 2.3 TEC Error Indicators . . . . . . . . . . . . . . . . . . . . . . . . . . . . .36

Table 3.1 Substitute Parameter Names . . . . . . . . . . . . . . . . . . . . . .50

Table 3.2 Invalid Syntax Command Strings. . . . . . . . . . . . . . . . . . . .52

Table 3.3 LDC-3700C Commonly Used Commands. . . . . . . . . . . . .54

Table 3.4 Default Settings for Output Off Registers. . . . . . . . . . . . . .58

Table 4.1 Remote Command Summary Reference List. . . . . . . . . . .64

Table 5.1 Recommended Test Equipment. . . . . . . . . . . . . . . . . . . .136

Table 5.2 Required Calibration Components. . . . . . . . . . . . . . . . . .138

Table 5.3 Symptoms and Actions . . . . . . . . . . . . . . . . . . . . . . . . . .155

Table 5.4 Error Code Classifications . . . . . . . . . . . . . . . . . . . . . . . .157

Table 5.5 Error Messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .157

04_09 LDC-3700C Series vii



LIST OF TABLES



viii LDC-3700C Series

S

CAUTION

WARNING

WARNING

AFETY AND

The Safety and Warranty Information section provides details about cautionary
symbols used in the manual, safety markings used on the instrument, and
information about the Warranty including Customer Service contact information.

W

ARRANTY INFORMATION

Safety Information and the Manual

Throughout this manual, you will see the words Caution and Warning indicating
potentially dangerous or hazardous situations which, if not avoided, could result in
death, serious or minor injury, or damage to the product. Specifically:

!

Caution indicates a potentially hazardous situation which can result in minor or
moderate injury or damage to the product or equipment.

Warning indicates a potentially dangerous situation which can result in serious injury or
death.

Visible and/or invisible laser radiation. Avoid direct exposure to the beam.

General Safety Considerations

If any of the following conditions exist, or are even suspected, do not use the
instrument until safe operation can be verified by trained service personnel:

• Visible damage

• Severe transport stress

• Prolonged storage under adverse conditions

• Failure to perform intended measurements or functions

If necessary, return the instrument to ILX Lightwave, or authorized local ILX
Lightwave distributor, for service or repair to ensure that safety features are
maintained (see the contact information on page xiii).

LDC-3700C Series ix



All instruments returned to ILX Lightwave are required to have a Return
Authorization Number assigned by an official representative of ILX Lightwave
Corporation. See Returning an Instrument on page xi for more information.

S

AFETY

This section describes the safety symbols and classifications.
Technical specifications inclu ding electrical ratings and weight are included within

the manual. See the Table of Contents to locate the specifications and other
product information. The following classifications are standard across all ILX
Lightwave products:

• Indoor use only

• Ordinary Protection: This product is NOT protected against the harmful ingress of moisture.

• Class I Equipment (grounded type)

SAFETY SYMBOLS

S

YMBOLS

• Mains supply voltage fluctuations are not to exceed ±10% of the nominal supply voltage.

• Pollution Degree II

• Installation (overvoltage) Category II for transient overvoltages

• Maximum Relative Humidity: <80% RH, non-condensing

• Operating temperature range of 0°C to 40°C

• Storage and transportation temperature of -40°C – 70°C

• Maximum altitude: 3000 m (9843 ft)

• This equipment is suitable for continuous operation.

Safety Marking Symbols

This section provides a description of the safety marking symbols that appear on
the instrument. These symbols provide information about potentially dangerous
situations which can result in death, injury, or damage to the instrument and other
components.

x LDC-3700C Series



WAR RA NT Y

or
(I)

or

(O)

Caution,
refer to
manual

Caution, risk
of electric
shock

On: In position of a bistable push control.
The slash (I) only denotes that mains are on.

W

ARRANTY

ILX LIGHTWAVE CORPORATION warrants this instrument to be free from
defects in material and workmanship for a period of one year from date of
shipment. During the warranty period, ILX will repair or replace the unit, at our
option, without charge.

Earth
ground
Te r mi n a l

Protective
Conductor
Te r mi n a l

Alternating
current

Caution, hot
surface

Off: Out position of a bistable push control.
The circle (O) only denotes that mains are off.

Visible and/or
invisible laser
radiation

Frame or
chassis
Te r mi n a l

Limitations

This warranty does not apply to fuses, lamps, defects caused by abuse,
modifications, or to use of the product for which it was not intended.

This warranty is in lieu of all other warranties, expressed or implied, including any
implied warranty of merchantability or fitness for any particular purpose. ILX
Lightwave Corporation shall not be liable for any incidental, special, or
consequential damages.

If a problem occurs, please contact ILX Lightwave Corporation with the
instrument's serial number, and thoroughly describe the nature of the problem.

Returning an Instrument

If an instrument is to be shipped to ILX Lightwave for repair or service, be sure to:

1 Obtain a Return Authorization number (RA) from ILX Customer Service.
2 Attach a tag to the instrument identifying the owner and indicating the required service or

repair. Include the instrument serial number from the rear panel of the instrument.

LDC-3700C Series xi



WAR RA NT Y

3 Attach the anti-static protective caps that were shipped with the instrument and place the

instrument in a protective anti-static bag.

4 Place the instrument in the original packing container with at least 3 inches (7. 5 cm) of

compressible packaging material. Shipping damage is not covered by this warranty.

5 Secure the packing box with fiber reinforced strapping tape or metal bands.
6 Send the instrument, transportation pre-paid, to ILX Lightwave. Clearly write the return

authorization number on the outside of the box and on the shipping paperwork. ILX
Lightwave recommends you insure the shipment.

If the original shipping container is not available, place your instrument in a
container with at least 3 inches (7.5 cm) of compressible packaging material on all
sides.

Repairs are made and the instrument returned transportation pre-paid. Repairs
are warranted for the remainder of the original warranty or for 90 days, whichever
is greater.

Claims for Shipping Damage

When you receive the instrument, inspect it immediately for any damage or
shortages on the packing list. If the instrument is damaged, file a claim with the
carrier. The factory will supply you with a quotation for estimated costs of repair.
You must negotiate and settle with the carrier for the amount of damage.

xii LDC-3700C Series



WAR RA NT Y

Comments, Suggestions, and Problems

To ensure that you get the most out of your ILX Lightwave product, we ask that
you direct any product operation or service related questions or comments to ILX
Lightwave Customer Support. You may contact us in whatever way is most
convenient:

Phone . . . . . . . . . . . . . . . . . . . . . . . . . . . [phone] or [phone]

Fax . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [phone]

Email. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [e-mail]

Or mail to:
ILX Lightwave Corporation

P. O. Box 6310
Bozeman, Montana, U.S.A 59771
www.ilxlightwave.com

When you contact us, please have the following information:

Model Number:

Serial Number:

End-user Name:

Company:

Phone:

Fax:

Description or sketch of what

is connected to the ILX

Lightwave instrument:

Description of the problem:

If ILX Lightwave determines that a return to the factory is necessary, you are
issued a Return Authorization (RA) number. Please mark this number on the
outside of the shipping box.

You or your shipping service are responsible for any shipping damage when
returning the instrument to ILX Lightwave; ILX recommends you insure the
shipment. If the original shipping container is not available, place your instrument

LDC-3700C Series xiii



WAR RA NT Y

in a container with at least 3 inches (7.5cm) of compressible packaging material
on all sides.

We look forward to serving you even better in the future!

xiv LDC-3700C Series



CHAPTER 1



INTRODUCTION AND SPECIFICATIONS

This chapter is an introduction to the LDC-3700C Series Laser Diode Controllers
and contains unpacking information, instructions on how to install and apply
power, maintenance information, specifications, and listings of the LDC-3700C
options and accessories.

Product Overview

The LDC-3700C Series Laser Diode Controllers are a combination current
source/temperature controller. The current source provides a high stability output
with a fully redundant current limit and multiple laser protection features. The
built-in temperature controller can work with most temperature sensors and TE
modules to deliver precise laser temperature control over a wide range of
temperatures. The LDC-3700C Series' fast, sophisticated USB or GPIB
communications lets you automate your experiment.

Initial Inspection

When you receive your LDC-3700C Controller , verify t hat the following items were
shipped with the instrument:

• LDC-3700C Laser Diode Controller

• LDC-3700C Series Manual

• Power Cord

• Shipping Kit

LDC-3700C Series 1



CHAPTER 1

INTRODUCTION AND SPECIFICATIONS

Installing the LDC-3700C

Installing the LDC-3700C

This section provides information about the necessary requirements to install the
LDC-3700C and how to begin operating the instrument.

Grounding Requirements

The LDC-3700C Laser Diode Controller comes with a three conductor AC power
cable. The power cable must be plugged into an approved three-contact electrical
outlet or used with a three-contact to two-contact adapter with the grounding wire
connected to an electrical ground (safety ground). The LDC-3700C supplied
power cable meets all applicable national safety standards.

AC Line Power Requirements

You can operate the LDC-3700C Series Controllers from a single phase power
source delivering nominal line voltages of 100, 120, 220, 230-240 VAC (all values
RMS) from 50 to 60 Hz. The line power voltage can vary ±10%. Maximum power
consumption is 360 VA (Volt-Amps). The instrument's operational voltage is
configured at the factory and cannot be changed. However, check to make sure
the voltage printed on the back panel of the instrument matches the power-line
voltage in your area.

Before connecting the LDC-3700C Laser Diode Controller to a power source, verify that
the AC power source matches the setting of the LDC-3700C's voltage printed on the rear
panel of the instrument.

To avoid electrical shock hazard, connect the instrument to properly earth-grounded
electrical receptacles only. Failure to observe this precaution can result in severe injury
or death.

USB

The USB connector is located on the back rear panel, directly below the GPIB
connector. This USB co nnector is the square "B"-style connector. A standard USB
A/B cable is required to communicate with the instrument. To communicate to the
instrument using USB, please install the Virtual Com Port Driver found on the
accompanying CD or website prior to connecting the unit to the PC. Please refer
to Chapter 3 for more detailed instructions on operating the instrument through
USB.

2 LDC-3700C Series



INTRODUCTION AND SPECIFICATIONS

Installing the LDC-3700C

CHAPTER 1

GPIB Connector

The IEEE 488.2 GPIB interface connector is located on the rear panel, directly
above the power input module and fuse (See Figure 1.2 on page 4). Attach the
GPIB cable to the 24-pin connector located on the rear panel. The connector is
tapered to ensure proper orientation. Finger tighten the two screws on the cable
connector.

A total of 15 devices can be connected together on the same GPIB interface bus.
The cables have single male/female connectors on each end so that several
cables can be stacked. This allows more than one cable to be attached to any
one device. However, the maximum length of the GPIB cables must not exceed
20 meters (65 feet) total, or 2 meters (6.5 feet) per device.

The GPIB Address

The talk and listen addresses on the LDC-3700C Series Laser Diode Controller
are identical. This GPIB address is read locally by pressing the GPIB LOCAL
switch with the address displayed on the "TEC" display. The controller comes
from the factory configured with the GPIB address set to 1. You can change the
LDC-3700C's GPIB address locally (via front panel). A procedure for changing
the address can be found in the section Changing the GPIB Address on page 46.

Tilt-Foot Adjustment

The LDC-3700C Series Laser Diode Controller comes standard with folding front
legs and two rear feet for use as a bench top instrument. Extending the front feet
so that the instrument front panel sits up makes it easier to view the LED displays.
To use them, place the unit on a stable base and rotate the front legs downward
until they lock into position.

Rack Mounting

The LDC-3700C Series Laser Diode Controller can be mounted in a standard
19-inch rack with the optional rack mount kits. The kits contain a rack mount
flange and hardware for mounting on either side of the enclosure. All rack mount
accessory kits contain detailed mounting instructions.

Operating the LDC-3700C Laser Diode Controller

Now that the LDC-3700C Laser Diode Controller is installed and ready for use,
you can begin to learn about its operation. The following figures are front and rear
photographic copies showing the functional keypad groupings, rear panel
connectors, and so on. Use these figures to familiarize yourself with the
LDC-3700C Controller. After that, use Chapter 2 for fundamentals of operating
the controller.

04_09 LDC-3700C Series 3



CHAPTER 1

INTRODUCTION AND SPECIFICATIONS

Installing the LDC-3700C

Figure 1.1 LDC 3700C Series Controller Front View

4 LDC-3700C Series



Potentially lethal voltages exist within the LDC-3700C Series Laser Diode Controller. To
avoid electric shock, do not perform any maintenance on the instrument. Qualified
service personnel are required to wear protective eyeglasses and anti-static wrist bands
while working on the LDC-3700C Series Laser Diode Controller circuit boards. High
voltages are present on and around the controller's printed circuit boards.

There are no user serviceable parts in the instrument, including the external fuses in the
AC power entry module. Contact ILX Customer Service for information about servicing
the instrument.

Figure 1.2 LDC-3700C Rear Panel

INTRODUCTION AND SPECIFICATIONS

Installing the LDC-3700C

CHAPTER 1

How to Obtain Repair Services

You may have to return your controller to the ILX Lightwave facility at some time
for repair or service whether it is under warranty or not. There is a charge for
repairs after the warranty period has expired. See Returning an Instrument on
page xi for shipping information and Customer Service contact information.

04_09 LDC-3700C Series 5



CHAPTER 1

INTRODUCTION AND SPECIFICATIONS

Laser Current Source Specifications

1

Laser Current Source Specifications

LDC-3714C LDC-3724C LDC-3744C

DRIVE CURRENT OUTOUT

Output Current Range 0 to 50 mA

0 to 100 mA

Setpoint Resolution 1 µA

2 µA
Setpoint Accuracy (% of FS) ±0.05% ±0.05% ±0.05%
Compliance Voltage 0-10V; adjustable 0-10V; adjustable 0-10V; adjustable
Temperature Coefficient <50 ppm/°C <50 ppm/°C <100 ppm/°C
Short-Term Stability (1 hour)
Long-Term St ability (24 hours)
Noise and Ripple (µA rms)

High Bandwidth Mode

Low Bandwidth Mode

Transients

Operational
1 kV EFT
Surge

5

6

2

3

4

<20 ppm <20 ppm <20 ppm

<40 ppm <40 ppm <40 ppm

<1.5 µA <4 µA <15 µA (lo range)

<1.5 µA <2 µA <10 µA

<2 mA <3 mA <4 mA

<5 mA <8 mA <10 mA

<8 mA <12 mA <8 mA

1

0 to 200 mA
0 to 500 mA

4 µA
10 µA

0 to 2000 mA
0 to 4000 mA

40 µA
80 µA

<20 µA (hi range)

COMPLIANCE VOLTAGE ADJUST

Range 0 - 10 V 0 - 10 V 0 - 10 V
Resolution 50 mV 50 mV 50 mV
Accuracy ±2.5% ±2.5% ±2.5%

DRIVE CURRENT LIMIT SETTINGS

Range 0 to 50.5 mA

0 to 101 mA
Resolution 0.25 mA

Accuracy ±0.5 mA

PHOTODIODE FEEDBACK

Type Differential Differential Differential
PD Reverse Bias 0 - 5 V, adjustable 0 - 5 V, adjustable 0 - 5 V, adjustable
PD Current Range 5 to 5000 µA 5 to 5000 µA 5 to 10000 µA
Output Stability

7

0.5 mA

±1 mA

0.02% 0.02% 0.02%

0 to 202 mA
0 to 505 mA

1 mA

2.5 mA
±2 mA

±5 mA

0 to 2020 mA
0 to 4040 mA

10 mA
20 mA

±20mA
±40 mA

6 LDC-3700C Series



INTRODUCTION AND SPECIFICATIONS

Laser Current Source Specifications

1

CHAPTER 1

LDC-3714C LDC-3724C LDC-3744C

Accuracy, setpoint (% of FS) ±0.05% ±0.05% ±0.05%

EXTERNAL ANALOG MODULATION

Input 0 - 10 V, 1 k 0 - 10 V, 1 k 0 - 10 V, 1 k
Transfer Function 5 mA/V

10 mA/V
Bandwidth (3 dB)

High Bandwidth
Low Bandwidth

8

DC to 1 MHz DC to 1 MHz DC to 250kHz

DC to 15 kHz DC to 15 kHz DC to 10 kHz

20 mA/V
50 mA/V

200 mA/V
400 mA/V

TRIGGER OUTPUT

Type TTL TTL TTL
Pulse Width 13 µs 13 µs 13 µs
Delay 12 ms 12 ms 12 ms

MEASUREMENT (DISPLAY)

Output Current Range 0 to 50.000 mA

0 to 100.00 mA

0 to 200.00 mA
0 to 500.00 mA

0 to 2000.0 mA

0 to 4000.0 mA
Output Current Resolution 0.001 mA 0.01 mA 0.1 mA
Output Current Accuracy ±0.05% FS ±0.05% FS ±0.1% FS
Photodiode Current Range 0 to 5000 µA 0 to 5000 µA 0 to 10000 µA
Photodiode Current Resolution 1 µA 1 µA 1 µA
Photodiode Current Accuracy ±2 µA ±2 µA ±4 µA
PD Responsivity Range (µA/mW)

9

0.00 to 1000.00 0.00 to 1000.00 0.00 to 1000.00
PD Responsivity Resolution (µA/mW) 0.01 for all product ranges
Optical Power Range (mW) 0.00 to 100.00 0.00 to 500.00 0.00 to 5000.0
Optical Power Resolution (mW) 0.01 0.01 0.1
Forward Voltage Range (V) 0.000 to 10.000 0.000 to 10.000 0.000 to 10.000
Forward Voltage Resolution 1 mV 1 mV 1 mV
Forward Voltage Accuracy

LASER CURRENT SOURCE NOTES

1. All values after a one-hour warm-up period at room temperature, 25°C.

2. Over any 1-hour period, half-scale output.

3. Over any 24-hour period, half-scale output.

4. Measured optically, evaluating noise intensity of a laser diode into a photodetector with 150 kHz bandwidth.

5. Maximum output current transient resulting from normal operational situa tions ( e.g., power on-o f f, current on-o f f), a s well as a ccident al situation s (e.g.,
power line plug removal).

6. Maximum output current transient resulting from a 1000V power-line transient spike.

7. Maximum monitor photodiode current drift over any 30 minute period. Assumes zero drift in responsivity of photod i od e.

8. 50% modulation depth at mid-scale output. Higher bandwidth is possible with smaller modulation signal.

9. Responsivity value is user-defined and is used to calculate the optical power.

10. Four wire voltage measurement at the load. Voltage measurement accuracy whil e driving cali bration l oad. Accuracy is depe ndent u pon loa d an d cabl e
used.

10

±2 mV ±2 mV ±2 mV

04_09 LDC-3700C Series 7



CHAPTER 1

INTRODUCTION AND SPECIFICATIONS

Temperature Controller Specifications

1

Temperature Controller Specifications

TEMPERATURE CONTROL OUTPUT

Temperature Control Range
Thermistor Setpoint Resolution Accuracy

-20°C to 20°C
20°C to 50°C

AD590 & LM335 Setpoint

-20°C to 50°C

Short Term Stability (1 hr)
Long Term Stability (24 hrs)
Output Type Bipolar, constant current source
Compliance Voltage >8 V DC
Short Circuit Output Current 4 Amps
Maximum Output Power 32 Watts
Current Noise and Ripple
Current Limit Range 0 to 4 Amps
Current Limit Set Accuracy ±0.05 Amps

2

-100.0°C to +199.9°C

0.1°C ±0.2°C

0.2°C ±0.2°C

4

0.1°C ±0.1°C

5

6

7

<0.004°C
<0.01°C

<1 mA rms

1

3

Control Algorithm Smart Integrator, Hybrid PI

TEMPERATURE SENSOR

Types

Thermistor
IC Temperature Sensor
RTD Sensor

8

NTC (2-wire)
AD590/LM335
Pt

/Other 100-ohm RTD

100

Thermistor Sensing Current 10 µA/100 µA
Sensor Bias AD590 = 8 V LM335 = 1 mA RTD = 0.8 mA

8

Useable Thermistor Range 25 to 450,000 , typical
Typical Sensor Output

AD590 Current Output
LM335 Voltage Output
RTD (Pt

) Resistance

100

9

I(25°C) = 298.2 µA, I
V(25°C) = 2.73 V, V

= 1 µA/K

t

= 10 mV/K

t

R(25°C) = 109.73 

User Calibration Thermistor: Steinhart-Hart, 3 constants IC Sensors,

RTD = Two-point

8 LDC-3700C Series



INTRODUCTION AND SPECIFICATIONS

General LDC-3700C Specifications

CHAPTER 1

TEC MEASUREMENT (DISPLAY)

Range

10

Resolution Accuracy

Temperature

10 µA Setting
100 µA Setting

11

-100.0°C to 199.9°C 0.01°C ±0.1°C

12

-100.0°C to 199.9°C 0.01°C ±0.05°C

Thermistor Resistance

10 µA Setting
100 µA Setting

0.01 to 450.00 k 0.01 k ±0.05%

0.001 to 45.000 k 0.001 k ±0.05%

TE Current -4.000 to 4.000 A 0.001 A ±0.04 A

13

Voltage (remote only)

TEMPERATURE CONTROL NOTES

1. All values after a one-hour warm-up period at room temperature, 25°C.

2. Software limits of range. Actual range possible depends on the physical load, thermistor type, and TE module used.

3. Accuracy figures are quoted for a typical 10 k thermistor and 100 µA current setting. Accuracy figures are relative to the
calibration standard. Both resolution and accuracy are dependent upon the user-defined configuration of the instrument .

4. Accuracy depends on the sensor model selected, the calibration standard, and the user-defined onfiguration of the instrument.

5. Over any 1-hour period, half-scale output, controlling an LDM-4412 mount @ 25°C, with 10 k thermistor on 100 µA setting.

6. Over any 24-hour period, half-scale output, controlling an LDM-4412 mount @ 25°C, with 10 k thermistor on 100 µA setting.

7. Measured at 1 Amp output over a bandwidth of 10 Hz - 10 MHz.

8. When ordered with TSC-599 RTD Sensor Converter.

9. Nominal temperature coefficients, I

10. Software limits of display range.

11. Using a 100 k thermistor, controlling an LDM-4412 mount over -30°C to +25°C.

12. Using a 10 k thermistor, controlling an LDM-4412 mount over -30°C to +25°C.

13. Voltage measurement accuracy while driving calibration load. Accuracy is depen dent upon load used.

-10.000 to 10.000 V 1 mV ±30 mV

and Vt, apply over the rated IC temperature sensor range.

t

General LDC-3700C Specifications

CONNECTORS

Photodiode Monitor and Current Source Connector 9-pin, D-sub, female
External Modulation Connector BNC
Temperature Controller 15-pin, D-sub, female
Trigger Output BNC
Chassis Ground 4 mm banana jack

GPIB INTERFACE

Meets ANSI/IEEE Std 488.1 - 1987
Meets ANSI/IEEE Std 488.2 - 1987

USB INTERFACE

04_09 LDC-3700C Series 9



CHAPTER 1

INTRODUCTION AND SPECIFICATIONS

General LDC-3700C Specifications

GENERAL

Size (H x W x D) 5.0” x 13.9” x 13.6”

(127 mm x 353 mm x 345 mm)

Weight

LDC-3714C
LDC-3724C
LDC-3744C

Power Requirements 100 - 115 VAC, 220 - 240 VAC, 48 - 66 Hz
Temperature 0°C to +40°C operating

Humidity < 90% relative humidity, non-condensing
Laser Safety Features Key switch, interlock and output delay

LASER Display Type 5-digit, green LED
TEC Display Type 5-digit, green LED

~22.5 lbs. (10.2 kg)
~22.5 lbs. (10.2 kg)
~25 lbs. (11.3 kg)

-40°C to +70°C storage

(meets CDRH US21 1040.10)

10 LDC-3700C Series



INTRODUCTION AND SPECIFICATIONS

General LDC-3700C Specifications

CHAPTER 1

Available Options and Accessories

Options and accessories available for the LDC-3700C Series Controllers include
the following:

Table 1.1 Options and Accessories

DESCRIPTION MODEL NUMBER

Rack mount flange kit
(enables installation into a standard 19 inch wide rack)

Temperature Controlled Laser Diode Mount LDM-4407
Temperature Controlled Laser Diode Mount (available with collimating

assembly)
DIL Laser Diode Mount LDM-4982
Butterfly Laser Diode Mount LDM-4984
High Power Laser Diode Mount LDM-4442
Current Source Interconnect Cable (unterminated) CC306S
Current Source Interconnect Cable (terminated) CC305S
TEC Interconnect Cable (unterminated) CC501S
TEC Interconnect Cable (terminated) CC505S
Calibrated 10 k Thermistor TS-510
Uncalibrated 10 k Thermistor TS-520
Uncalibrated AD590LH IC Temperature Sensor TS-530
Uncalibrated LM335AH IC Temperature Sensor TS-540
RTD Temperature Sensor Converter TSC-599

RM-136

LDM-4412

Other Laser Diode Mounts and Thermistor models are available. Please contact
ILX Lightwave for information on additional options for your applications.

04_09 LDC-3700C Series 11



CHAPTER 1

INTRODUCTION AND SPECIFICATIONS

General LDC-3700C Specifications

12 LDC-3700C Series



CHAPTER 2



OPERATIONS

This chapter introduces you to the operation of the LDC-3700C Series Controllers.
It offers instructions for connecting your laser to the current source and
temperature controller and describes powering up the instrument. This chapter
also contains step by step procedures that teach you how to operate your
controller in Constant Current Mode, Constant Power Mode, and to operate the
temperature controller in Constant Temperature Mode. ILX recommends that you
review the contents of this chapter at a minimum before operating your new
controller.

Applying Power to your LD Controller

To turn on the LDC-3700C Controller, rotate the key in the "POWER" section of
the front panel from "O" to "I". This action initiates the power on sequence. If the
LDC-3700C does not appear to turn on, verify that it is connected to line power. If
line power is not the problem, remove the power cord and check the line power
fuse.

Note: The instrument contains a laser current source that has remote interlock capability.
This allows you to connect the interlock circuit to an external switch for safety. If the
interlock is removed, the laser current output is disabled. Refer to the laser module manual
for details about the interlock function.

The instrument is also equipped with a laser enable key switch. This ensures that the laser
current can be turned on only if the key is inserted and in the On position.

The Power On Sequence

During the power-up sequence, the following takes place. For about three
seconds all indicators light up, and all of the 7-segment displays indicate "8". Then
all lamps are turned off for three seconds. Next, the firmware version displays in
the LASER display section followed by the TEC sensor switch position displayed
on the TEC display. Then, a self-test is performed to ensure that the instrument's
hardware and processor are communicating. After this test, the instrument is
ready to operate, and is configured to the state it was in when the power was last
shut off.

LDC-3700C Series 13



CHAPTER 2

The Power On State

OPERATIONS

You can choose to "clear" the last saved instrument state by recalling the default
values. These values are stored in BINS to which you can save or recall
instrument configurations (described in more detail in Chapter 5). "BIN 0" contains
all of the default configurations listed below.

Note: If the instrument cannot successfully complete the power on test, an error message
of E-512 or E-513 will be displayed on the Laser Display . See Troubleshooting on page 155
for a list of error codes and actions to take when your instrument indicates these errors.

37x4C Series Default Configuration:

• GPIB mode in LOCAL via front panel, or in

REMOTE via GPIB

• RECALL BIN number = 0 • TEC DISPLAY enabled, in T mode

• TEC and LASER adjust not selected • TEC Display showing actual temperature

• LASER DISPLAY enabled, in I mode • Constant T mode selected

• LASER display showing measured current • Temperature Set Point = 20°C

• Constant I, low bandwidth mode selected • LIM T

• LIM V = 10 Volts • I

• LIM I (high range) = 1000 / 125 / 25 mA

(3744C / 3724C / 3714C)

• LIM I (low range) = 500 / 50 mA / 12.5 mA
(3744C / 3724C / 3714C)

• LIM P = 5000 / 1000 / 200 mW
(3744C / 3724C / 3714C)

• LASER output off • TEC output off

• LASER Tolerance values = 10.0 mA, 1.0 s

(3744C)

• LASER STEP value = 1

• LASER I Set Point = 0 mA

• LASER P

• LASER IPD Set Point = 0 µA

• CAL PD = 0 mA/mW

Set Point = 0 mW

PD

• PARAMETERS not selected

set to 99.9°C

HI

Set Point = 1.0 Amp

TE

• LIM ITE = 2.0 Amps

• GAIN = 30

• C1 = 1.125 (x 10

• C2 = 2.347 (x 10

• C3 = 0.855 (x 10

• TEC Tolerance values = 0.2°C, 5 seconds

• LASER Tolerance values = 1.0 mA, 1.0 s

(3724C/3714C)

• Resistance/Reference Set Point = 1 ohm / mA / mV
(depending on the setting of the SENSOR
SELECT switch)

-3

)

-4

)

-7

)

14 LDC-3700C Series

