ILX Lightwave LDX-3620B User manual

Table of Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . i
List of Figures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . v
Safety and Warranty Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . vii
Safety Information and the Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .vii
General Safety Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .vii
Safety Symbols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . viii
Safety Marking Symbols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . viii
Warranty . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ix
Comments, Suggestions, and Problems . . . . . . . . . . . . . . . . . . . . . . . . . . . . x
Chapter 1 Introduction and Specifications
Product Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Initial Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Installing Your LDX-3620B Ultra Low Noise Current Source . . . . . . . . . . . . . 2
Power Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Grounding Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Tilt Foot Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Operating the LDX-3620B Ultra Low Noise Current Source . . . . . . . . . . . . . . 3
Rear Panel Controls and Connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
OUTPUT Connector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

PHOTODIODE Feedback Input Jack . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
CHASSIS GROUND Connector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
DC POWER Input . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Options and Accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Chapter 2 Operation
Applying Power to Your LDX-3620B . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Battery Charging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Low Battery Condition and Shutdown . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Connecting to the Laser . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Load Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Interlock Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Photodiode Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Front Panel Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Initial Front Panel Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
DISPLAY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
DISPLAY Selector . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
BATTERY Charge Indicator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
CHARGE Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
OUTPUT Adjust . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
LIMIT Current Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Instrument MODE Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
OUTPUT On/Off . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Photodiode Feedback Gain Adjustments . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Modulating the Output Current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Output Error Indicators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
CURRENT LIMIT Indicator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
OVER VOLTAGE Indicator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
OPEN CIRCUIT Indicator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Chapter 3 Maintenance and Calibration
Battery Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Battery Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Fuse Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Laser Diode Measurement Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Photodiode Measurement Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
Disassembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Appendix A Troubleshooting

Figure 1.1 LDX-3620B Front Panel . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Figure 1.2 LDX-3620B Rear Panel . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Figure 2.1 Common Laser Cathode - Photodiode Cathode . . . . . . . 12
Figure 2.2 Common Laser Cathode - Photodiode Anode . . . . . . . . 12
Figure 2.3 Common Laser Anode - Photodiode Cathode . . . . . . . . 12
Figure 2.4 Common Laser Anode - Photodiode Anode . . . . . . . . . . 13
Figure 2.5 Rear Panel Laser Output Connector . . . . . . . . . . . . . . . . 13
Figure 2.6 Photodiode Feedback Block Diagram . . . . . . . . . . . . . . . 21
Figure 3.1 Battery Replacement . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Figure 3.2 TR5 Fuse Replacement Position . . . . . . . . . . . . . . . . . . . 27
Figure 3.3 200 mA Calibration Potentiometer Position . . . . . . . . . . . 29
Figure 3.4 Photodiode and 500 mA Measurement
Calibration Position . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Figure 3.5 Top Chassis Cover Removal . . . . . . . . . . . . . . . . . . . . . . 31

SAFETY AND WARRANTY INFORMATION
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.
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 later in this section.)
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 ix for more information.

SAFETY SYMBOLS
This section describes the safety symbols and classifications.
Technical specifications including 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)
•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 to 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.
Caution,
refer to
manual
Earth
ground
Terminal
Alternating
current
Visible and/or
invisible laser
radiation
Caution, risk
of electric
shock
Protective
Conductor
Terminal
Caution, hot
surface
Frame or
chassis
Terminal
On: In position of a bistable push control.
The slash (I) only denotes that mains are on.
Off: Out position of a bistable push control.
The circle (O) only denotes that mains are off.
or
(I) or
(O)

WARRANTY
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.
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:
1Obtain a Return Authorization number (RA) from ILX Customer Service.
2Attach 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.
3Attach the anti-static protective caps that were shipped with the instrument and place the
instrument in a protective anti-static bag.
4Place 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.
5Secure the packing box with fiber reinforced strapping tape or metal bands.
6Send 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.
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]
On the web at: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ilx.custhelp.com
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 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
in a container with at least 3 inches (7.5 cm) of compressible packaging material
on all sides.
We look forward to serving you even better in the future!

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This chapter is an introduction to the LDX-3620B Ultra Low Noise Laser Diode
Current Source. It contains unpacking information, instructions on how to install
and apply power, and safety considerations and instructions. It also contains
specifications and information on options and accessories.
If any of the following symptoms exist, or are even suspected, remove the LDX-3620B
from service. Do not use the LDX-3620B until trained service personnel can verify safe
operation.
Visible damage
Severe transport stress
Prolonged storage under adverse conditions
Failure to perform intended measurements or functions
If necessary, return the LDX-3620B to ILX Lightwave for service and repair to ensure that
safety features are maintained.
Product Overview
The LDX-3620B is a battery powered, ultra low noise current source, optimized for
narrow linewidth or stable wavelength laser diode applications. Instrument
features include:
•Low noise, battery based design
•Built-in battery charger and front panel battery charge indicator
•High output stability, (<10 ppm)
•Current limit protection
•Two output current ranges (200 mA and 500 mA)
•Photodiode feedback input for constant optical power operation

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•Two current control inputs with up to 1 MHz bandwidth for precise laser tuning
•Low battery shutdown protection
Initial Inspection
When you receive your LDX-3620B, verify that the following items were shipped
with the instrument:
•LDX-3620B Ultra Low Noise Laser Diode Current Source
•User’s Manual
•DC Power Supply
•Power Cord
Verify the line voltage indicated on the rear panel is correct for your facility. Check
for damage from shipping.
Installing Your LDX-3620B Ultra Low Noise Current Source
Power Requirements
The LDX-3620B is a battery powered current source. It can be operated for up to
16 hours before recharging the batteries. A low voltage DC power supply
(supplied with the instrument) is required to charge the batteries. The DC power
supply can be plugged into a single phase AC power source delivering nominal
line voltages in the range of 100 to 240 VAC +10% (all values RMS), from 50 to 60
Hz. This power supply is intended for indoor use only.
To avoid electrical shock hazard, connect the instrument to properly earth-grounded,
3-prong receptacles only. Failure to observe this precaution can result in severe injury or
death.
Grounding Requirements
The LDX-3620B Ultra Low Noise Current Sources comes with a low voltage DC
power supply and a three conductor AC power cable. The power cable must either
be plugged into an approved three contact electrical outlet or used with a three-
contact or two-contact adapter with the grounding wire connected to an electrical
ground (safety ground). The LDX-3620B’s DC power supply and power cable
meet IEC safety standards.

The
supplied
low
voltage
DC
power
supply
is
for
use
with
the
LDX-3620B
Ultra
Low
Noise
Current Source only. Do not use this power supply for any purpose other than running
the LDX-3620B.

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Figure 1.1 LDX-3620B Front Panel
Figure 1.2 LDX-3620B Rear Panel

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Rear Panel Controls and Connectors
OUTPUT Connector
The rear panel 9-pin D-sub connector pin-outs are shown in Figure 2.5 in Chapter
2. The LDX-3620B output current is sourced (+) from pins 8 and 9 and the current
returned (-) to pins 4 and 5. The monitor photodiode feedback current is input to
pin 7 (+) and returned from pin 6 (-). The feedback leads should be shielded with
an earth-ground shield available on pin 3. Pins 1 and 2 of the rear panel OUTPUT
can be connected to an external safety interlock switch to disable the LDX-3620B
current output when the switch is opened.
PHOTODIODE Feedback Input Jack
The photodiode feedback current may optionally be input through a rear panel
BNC jack. This jack is connected in parallel with pins 6 and 7 of the rear panel 9
pin D subminiature connector.
CHASSIS GROUND Connector
Chassis ground is available on the rear of the unit through a banana jack
connected to the LDX-3620B chassis. When a three-wire line cord with earth
ground is used, the chassis of the LDX-3620B is connected to the ground lead of
the power cord.
DC POWER Input
A input is provided for charging the internal batteries from a DC desktop 50W
power supply provided with the LDX-3620B. An IEC 320-C14 receptacle is
required for AC input to the power supply. The plug is a standard type R1B: DIN
5-pin which connects directly to the receptacle on the rear panel. The power
supply provides 5V, +15V, and -15V to the instrument.
The instrument can be operated in any mode with the DC power supply
connected.

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Specifications