THORLABS Blueline Series User manual

Operation Manual
Thorlabs Blueline™ Series
Laser Diode Controller
LDC2xx
2006

Version: 1.11
Date: 20.06.2006
Copyright© 2006, Thorlabs GmbH, Germany

Contents page
1General Information 1
1.1 At a Glance 1
1.2 Safety 3
1.3 Ordering codes and accessories 5
2Getting Started 6
2.1 Unpacking 6
2.2 Preparation 6
2.3 Operating elements 7
2.3.1 Operating elements on front panel 7
2.3.2 Operating elements on rear panel 8
2.4 First operation 9
3Operating the LDC2xx 10
3.1 Connecting components 10
3.1.1 9-pole SUB-D output jack 10
3.1.2 Interlock and control LED for LASER ON 11
3.1.3 Connecting the laser diode and photodiode 12
3.1.4 Analog control output for the laser current 14
3.2 Setting the current limit "ILIM" 15
3.3 Selecting the laser diode polarity 15
3.4 Constant current mode (CONST I) 17
3.5 Constant power mode (CONST P) 18
3.5.1 Changing the "IPD" setting range 20
3.6 Calibrating the optical power display 21
3.7 Analog modulation of the laser diode 21
3.8 Over-temperature-protection of the LDC2xx 22
4Remote control 23
5Maintenance and Repair 24
5.1 Maintenance 24
5.2 Line voltage setting 25
5.3 Replacing the mains fuse 26
5.4 Internal Fuse Replacement 27
5.5 Troubleshooting 28
6Appendix 30
6.1 Warranty 30
6.2 Certifications and compliances 31
6.3 Technical data 33

6.3.1 Common Data 33
6.3.2 Individual data LDC200V 34
6.3.3 Individual data LDC201U 35
6.3.4 Individual data LDC202B 36
6.3.5 Individual data LDC205B 37
6.3.6 Individual data LDC210B 38
6.3.7 Individual data LDC220 39
6.4 Thorlabs “End of Life” policy (WEEE) 40
6.4.1 Waste treatment on your own responsibility 40
6.4.2 Ecological background 41
6.5 List of acronyms 42
6.6 List of figures 42
6.7 Addresses 43

We aim to develop and produce the best solution for your application in the
field of optical measurement technique. To help us to live up to your
expectations and develop our products permanently we need your ideas and
suggestions. Therefore, please let us know about possible criticism or ideas.
We and our international partners are looking forward to hearing from you.
Thorlabs GmbH
This part of the instruction manual contains all the specific information on how to
operate a current module LDC2 xx. A general description is followed by explanations
on how to operate the unit manually. You will also find information about a simple
remote control of the unit.
Attention
This manual contains “WARNINGS” and “ATTENTION” labels in this
form, to indicate personal danger or possible damage to equipment.
Please read these advises carefully!
NOTE
This manual also contains “NOTES” and “HINTS” written in this form.

1.1 At a Glance
LDC2xx / page 1
1 General Information
1.1 At a Glance
The laser diode controllers of the series LDC200 by Thorlabs GmbH are extremely
precise controllers for laser diodes and LEDs. If a temperature controller by Thorlabs
GmbH is used additionally the injection current or the optical output power and the
temperature of the connected laser diode can be controlled simultaneously.
The LDC200V is designed for safe operation of VCSEL laser diodes.
The LDC201U provides ultra low noise current (<0.2µA RMS).
The new suffix “B” controllers offer an enhanced compliance voltage (>10V) for use
with blue laser diodes.
To protect the laser diode against dam age the LDC2xx provides the following
protection circuits:
• Softstart function
• Adjustable limitation of injection current
• Interlock (open circuit monitoring of the laser diode mount connection)
• Electronic shortcircuit for the laser diode in off-mode
• Separate key to switch the laser diode current on and off
• Monitoring LED for LASER ON mode
The LDC2xx is easy to use due to the clearly structured front panel.
Operating parameters are shown on an illuminated 4½-digit LCD display. The
parameter to be displayed is selected with a toggle switch.
The switch on/off delay and the softstart function protect the laser diode against
undesired transients.
An independent hardware limit for the inject ion current can be set with a 20-turn
potentiometer. This protects the laser diode against operating errors.
With the output open the laser diode is shortcircuited electronically so no voltage is
applied to the laser diode.

1.1 At a Glance
LDC2xx / page 2
When turned on the laser diode controller L DC2xx is automatica lly in LASER OFF
mode. The laser current can be switched on/off with a separate key at the front panel.
Laser diode and photodiode are connec ted by a 9-pin D-sub jack at the rear of the
unit. The output for the laser diode and the input for the photodiode are bipolar, thus
all polarities of commercial available laser diodes can be connected.
With a control signal at the output jack an external LED can be used to indicate
LASER ON.
The injection current or the optical output power of the laser diode can be modulated
via a modulation input at the rear of the unit.
For monitoring purposes a voltage proportional to the laser diode current is provided
at an analog control output at the rear.
If an error occurs or the limit for the la ser current is reached, the corresponding LED
lights up and a short beep gives a warning.
The installed mains filter and careful tr ansformer shielding provide low ripple and
noise at the output.
The internal cooling of the LDC200 with a fan protects the unit against overheating in
case of high environmental temperatures.
With free air circulation a safe operation of the unit is guaranteed up to 40 °C ambient
temperature.
Attention
Do not obstruct the air-ventilation slots in the housing!
If a laser diode head and the corresponding cable (CAB 400) by Thorlabs GmbH is
used, damages caused by wrong connections are impossible.

1.2 Safety
LDC2xx / page 3
1.2 Safety
Attention 
All statements regarding safety of operation and technical data in
this instruction manual will only apply when the unit is operated
correctly.
Before applying power to your LDC2xx system, make sure that the
protective conductor of the 3 conductor mains power cord is cor-
rectly connected to the protective earth contact of the socket outlet!
Improper grounding can cause electric shock with damages to your
health or even death!
Also make sure that the line voltage setting marked on the rear panel
agrees with your local supply and that the corresponding fuses are
inserted. If not, please have a service technician change the voltage
(see section 5.2).
Changing of the mains fuse can be done by the customer (see
section 5.3, Replacing the mains fuse)
The unit must not be operated in explosion endangered environ-
ments!
Laser and photodiodes must only be connected with duly shielded
connection cables.
Only with written consent from Thorlabs GmbH may changes to
single components be carried out or components not supplied by
Thorlabs GmbH be used.
This precision device is only dispatchable if duly packed into the
complete original packaging including the plastic form parts. If
necessary, ask for a replacement package.

1.2 Safety
LDC2xx / page 4
Attention 
Laser modules can deliver up to several 100mW of (maybe) invisible
laser radiation!
When operated incorrectly, this can cause severe damage to your
eyes and health!
Be sure to pay strict attention to the safety recommendations of the
appropriate laser safety class!
This laser safety class is marked on your external laser source used.
Attention 
Mobile telephones, handy phones or other radio transmitters are not
to be used within the range of three meters of this unit since the
electromagnetic field intensity may then exceed the maximum
allowed disturbance values according to EN 50 082-1.