Wavelength Electronics Laboratory Series User manual

USER GUIDE
Low-Noise QCL Driver — Laboratory Series1
TABLE OF CONTENTS PAGE
GENERAL OVERVIEW 2
SAFETY 3
QUICK CONNECT GUIDE 4
PIN DESCRIPTIONS 6
EXTERNAL MODULATION TRANSFER FUNCTIONS 6
ELECTRICAL SPECIFICATIONS 7
THEORY OF OPERATION 9
OPERATING INSTRUCTIONS (STAND-ALONE) 9
OPERATING INSTRUCTIONS (REMOTE) 17
TROUBLESHOOTING 22
ADDITIONAL TECHNICAL NOTES 25
MECHANICAL SPECIFICATIONS 27
CE DECLARATION OF CONFORMITY 28
WARRANTY & CERTIFICATION 29
ORDERING INFORMATION
PART NO DESCRIPTION
QCL500 LAB 500 mALow Noise QCL Instrument
QCL1000 LAB 1.0 A Low Noise QCL Instrument
QCL1500 LAB 1.5 A Low Noise QCL Instrument
QCL2000 LAB 2.0 A Low Noise QCL Instrument
NOISESCAN Noise Characterization Scan
55-110014 SMA-BNC Cable
55-110015 USB Cable
WCB310 Shielded SMA-SMA Cable
QCL TL LOW Resistive Test Load for QCL500 or
QCL1000
QCL TL 1500 Resistive Test Load for QCL1500
QCL TL 2000 Resistive Test Load for QCL2000
RCKMT-LAB SNGL 19” Single Unit Rack Mount Kit
RCKMT-LAB DUAL 19” Double Unit Rack Mount Kit
INTLK REPL KIT
(included with purchase)
Interlock Replacement Kit with
BNC terminator and modified
D-SUB connector to override
interlocks
e
Pb
RoHS
Compliant
Applies to Product Revision A
© April 2015
1Covered by U.S. Patents 6,696,887; 6,867,644 and 7,176,755. Licensed from Battelle Memorial Institute

2
• Output currents of 500 mA, 1 A, 1.5 A, 2 A
• Low noise: <0.4 A RMS up to 100 kHz
(QCL500, typical)
• Compliance voltage is adjustable, 10 to 20 V
(NOTE: The unit will only deliver the voltage
that the load requires, up to the compliance
voltage limit.)
• Analog modulation up to 2-3 MHz
• Constant Current Mode operation
• Touchscreen with intuitive user interface
• CE compliant, compatible with CDRH laser
regulations
• Feature-rich for research projects
»USB and Ethernet interfaces with software
included
»Auto voltage/current scan function
»Data collection using a computer or USB
flash drive
»Field upgradeable firmware
»Sophisticated error handling
»Save and recall functions for specific set
ups
• Rack mountable: 2 U height and ½ rack width
• Safety features protect your QCL investment
»Adjustable soft-clamp current limit, with
Brick-Wall Never-Exceed circuitry
»Password protection available to lock out a
selectable control set
»Key switch, active, and passive interlocks
»Brown-out & overvoltage protection
»Power supply overcurrent protection
»Driver over-temperature protection circuit
»Relay shorts output when current is
disabled
»AC input and patented power supply
filtering
»2 second turn-on delay — adjustable
»1.5 msec current ramp
F E A T U R E S
GENERAL OVERVIEW
THE LOWEST-NOISE DRIVER
AVAILABLE
These low noise QCL instruments have the lowest current
noise density of any commercially available. Powering your
QCL with this patented1driver gives you narrow linewidth,
stable center wavelength, and repeatable scans.
INTUITIVE USER INTERFACE AND
SUPERIOR SOFTWARE CONTROL
With Wavelength’s plug and play instrument, you have the
ability to quickly set the controls using either the instrument or
a remote computer.
PROTECT YOUR QCL INVESTMENT
All the essential control and monitor functions you expect in a
Wavelength laser driver are incorporated into this instrument,
along with protection circuitry to safeguard your QCL from
minor power source faults, over-temperature conditions, and
electrical faults.
The soft-clamping current limit can be set without enabling the
driver output, and uses a brick-wall never-exceed limit circuit
to protect the QCL from potentially damaging overcurrent
situations.
OEM VERSION AVAILABLE
Once you have finalized your work, the QCL circuitry is
available in compact OEM versions.
APPLICATIONS
Due to their unique construction, QCLs operate with high
power in the near-IR through terahertz ranges. These
wavelengths are particularly suited to detection of molecules
significant to humans.
Applications for the lower noise QCL driver include: remote
detection of explosive materials, medical diagnosis using the
breath, non-invasive glucose testing, emissions monitoring of
the atmosphere or marine environments, and pharmaceutical
process quality control. Additional applications include
anesthesia and hospital air quality monitoring, leak detection,
and remote imaging.
1Covered by U.S. Patents 6,696,887; 6,867,644 and
7,176,755. Licensed from Battelle Memorial Institute

3
SAFETY
DEFINITIONS
CHASSIS GROUND Symbol
CAUTION: A condition that has the potential to
cause damage to property or instrument.
WARNING: A condition that has the potential to
cause bodily harm or death.
GENERAL
• Observe all Cautions and Warnings both in the User
Guide and on the instrument.
• Use the QCL instrument as specified in this guide or the
protection provided by this instrument may be impaired
and the warranty will be voided.
• Use good laser safety practices when using the QCL
instrument.
• Before proceeding, it is critical that you take precautions
to prevent electrostatic discharge (ESD) damage to your
laser.
• Locking the instrument with the key switch disables the
output current. The key can only be removed when in the
LOCK position.
POWER CORDS
• This equipment is grounded through the AC power cord
grounding conductor.
• Use only the earth-grounded power cords that are
recommended in this user guide.
• Route power cords and other cables so that they cannot
be damaged.
• Position the QCL instrument in a location that makes it
easy to quickly disconnect the power cord.
• To avoid fire hazard, use only the specified power cords
with the correct grounding, voltage, and current ratings.
FUSES
• Disconnect the power to the QCL instrument before
changing the fuses.
• To prevent damage to the QCLinstrument when replacing
fuses, locate and correct the problem that caused the fuse
to blow before re-applying power.
• To avoid fire hazard, use only the specified fuse with the
correct type number, voltage, and current ratings, and use
only the recommended replacement parts.
CAUTIONS
TheQCLinstrumenthas nouser-serviceable parts.
Other than the fuses, the QCL instrument is not
designed to be maintained by the user nor does it
contain any parts that can be repaired by the user.
All maintenance and repairs must be performed by
Wavelength or the warranty will be void.
Use a soft cloth to remove dust from the QCL
instrument. Do not expose the QCL instrument to
any liquids, sprays, or solvents. To avoid electrical
shock, unplug the power cord before cleaning the
instrument.
Before connecting to the power source, make sure
the correct cables and voltage for your area are
set. The voltage selection is available on the back
of the instrument. See the Quick Start Guide for
instructions on changing the voltage.
WARNINGS
Position the QCL instrument so that access to the
Main Power On/Off switch on the back panel is
easily accessed.
Do not use the QCL instrument if there is evidence
of damage from shipping; damaged equipment
can present significant safety hazards. If you
suspect the QCL instrument is damaged, contact
Wavelength technical support before attempting to
operate the instrument.
To avoid electrical shock, use the recommended
earth-grounded power cables and properly earth-
grounded, 3-prong receptacles only. Failure to
follow this precaution can result in severe injury.
To avoid injury, do not tell the engineers how to
do their jobs. Let them muddle through until they
decide to read the User Guide.

4
QUICK CONNECT GUIDE
INSTALL FUSE & SELECT VOLTAGE
Figure 1. Fuse Box and Voltage Selector
1. On the back panel, locate the Fuse Box and Voltage
Selector receptacle. (See the Rear Panel diagram on
page 10 for the location.)
2. Insert a small flathead screwdriver into the slot (1) at the
top of the receptacle and twist to open faceplate. The red
fuse drawer and fuses are located in the Ship Kit.
3. On the face of the fuse drawer are two voltage choices.
Based on your country, select the proper fuses to install.
VOLTAGE FUSE PART NUMBER
100-120 V 1.25 A, 250 V,
fast blow Littelfuse 5 x 20 mm,
Part #02351.25HXP
220-240 V 0.63 A, 250 V,
fast blow Littelfuse 5 x 20 mm,
Part #0217.630MXP
CAUTION: It is imperative that the correct voltage
is used. Serious damage can occur if the incorrect
voltage is selected.
4. Insert the fuses as shown in Figure 2, with a short fuse
at the contact end of the receptacle. Then, turn the drawer
until the correct voltage label is at the top and replace it
in the receptacle. Press firmly to make sure the drawer is
completely seated. It should be flush with the receptacle.
Figure 2. Fuse Installation and Voltage Selector
5. Close the faceplate, again pressing firmly until it is flush.
The correct voltage label is shown through the Voltage
Window (2) on the faceplate.
WIRE ATEST LOAD
Use of a test load is recommended for setup of the QCL
instrument. Use the Wavelength test loads listed on page 1, or
when building your own test load, a 10 resistor with a 50 W
power rating is recommended for the QCL500, QCL1000,
and QCL1500. For the QCL2000, a 50 W 5 resistor is
recommended.
• Install the test load by either connecting to the QCL SMA
port or wiring the load to PIN 5 and PIN 9 on the QCL
D-SUB as shown in Figure 3.
QCL
SMA QCL
1
1 NOTE: The SMA case is electrically connected to the QCL chassis.
QCL D-SUB
6789
12345
Figure 3. QCL Wiring Diagram
-V
Pin 9 QCL +
or SMA Outer Ring
Pin 5 QCL -
or SMA Center Pin
QCL Driver
Current Sink
QCL
Figure 4. QCL Polarity Diagram

5
SETUP INTERLOCKS
The Wavelength Interlock Replacement Kit includes a male
D-SUB with the passive interlock pins shorted and a BNC
terminator.
1. For the passive interlock, on the back panel, short PIN 1
and PIN 2 on the QCL D-SUB.
2. For the active interlock, on the back panel, insert a BNC
terminator in the ACTIVE LOCK BNC port.
3. On the front panel, the key switch must be on UNLOCK to
enable the current to the QCL.
TURN ON POWER
1. On the back panel, press the power switch to the |. The
front panel power button light pulses slowly.
2. On the front panel, press the Power button. The button
illuminates, the touchscreen activates, and the Control
screen is active.
3. The front panel displays dashes instead of digits until the
unit has finished its power-up sequence (~10 seconds).
SET LIMITS
1. Press to access the Limit Screen.
2. On the Limit screen, press the blue Limit Current value
and rotate the Adjustment knob to change to the desired
value. The instrument will beep when set.
NOTE: The Max Supply Voltage and Cable Resistance values
can be ignored for now.
ADJUST SETPOINT
1. Press to access the Control Screen.
2. Press the Setpoint current value and turn the Adjustment
knob to change it. The instrument will beep when set.
ENABLE CURRENT
Press the ENABLE button. There is a standard 2-second
delay before the button illuminates and the current flows.
SHUTDOWN THE INSTRUMENT
If the Enable button is illuminated, current is still flowing to
the test load. Before shutting down, the current needs to be
turned off.
1. Press the Enable button. The button light will turn off and
current to the QCL test load will stop.
2. On the front panel, press the Power button. The
touchscreen will go black but the button light slowly
pulses blue to indicate that the back Power button is still
on. NOTE: Turning off only the front Power button puts
the instrument in Standby mode.
3. On the back panel, press the power switch to O.

6
PIN DESCRIPTIONS
QCL D-SUB
Figure 4. Female 9-Pin D-SUB
Table 1. QCL D-SUB Pin-Out
PIN DESCRIPTION
1, 2 Passive interlock pins (must be shorted to enable
current)
3 Chassis ground
4 Not used
5 * QCL- (negative)
6 Not used
7 Not used
8 Not used
9 * QCL+ (positive)
SHELL Chassis ground
* NOTE: Use Pins 5 and 9 for current to the QCL.
MONITOR D-SUB
Figure 5. Male 9-Pin D-SUB
Table 2. Monitor D-SUB Pin-Out
PIN DESCRIPTION
1 Alignment LED (+5 V) can source 250 mA
2 Alignment LED ground
3 QCL current enabled indicator (+5 V TTL)
high = disabled
low, ground = enabled
4 QCL current enabled indicator ground
5 Not used
6 Analog setpoint monitor
7 Analog monitor ground
8 Analog output current monitor
9 Analog monitor ground
QCL SMA
QCL-
(
ne
g
ative
)
QCL
+
(
groun
d)
Figure 6. SMA Pin-Out
-V
Pin 9 QCL +
or SMA Outer Ring
Pin 5 QCL -
or SMA Center Pin
QCL Driver
Current Sink
QCL
Figure 7. QCL Polarity Diagram
BNC PINS
ACTIVE SIGNAL
GROUND
Figure 8. BNC Pins
EXTERNAL MODULATION BNC
TRANSFER FUNCTIONS
The external modulation input, setpoint monitor, and analog current
monitor transfer functions depend on the QCL instrument model and
are all as follows:
QCL500-LAB: 0.1 A / V.
QCL1000-LAB: 0.2 A / V.
QCL1500-LAB: 0.3 A / V.
QCL2000-LAB: 0.4 A / V.
The input range is always 0 – 5 V.
ACTIVE INTERLOCK BNC
Ground the center pin to the outer shell to override the interlock and
allow the current to flow to the QCL. If an external circuit won’t be
used, a 50 or 75 terminator is acceptable.
TRIGGER BNC
See Remote Operation on page 21.

7
ELECTRICAL SPECIFICATIONS
DRIVER OUTPUT CURRENT MIN TYP MAX UNITS NOTES
Output Current 0.5, 1.0, 1.5, or 2.0 A
RMS Noise Current 0.4 1.0 1.3 A RMS QCL1000 at 500 mA output, 100 kHz test bandwidth
Noise Current Density 1 2 4 nA / Hz QCL1000 at 500 mA, 10 test load
Stability, short and long term 5 10 15 ppm 25°C ambient
Temperature Coefficient 5 10 18 ppm / °C
Compliance Voltage Range 10 20 V
Internal Supply Voltage can be adjusted from the front
panel.
NOTE:Withthiscurrentsource,thevoltagedeveloped
across the load (laser) is not driven by the controller,
but by Ohm’s Law and the resistance of the load
(laser).
Slow Start Current Ramp (after
Enabled) 1.5 msec To setpoint
Delayed Start 2 sec User adjustable
EXTERNAL MODULATION MIN TYP MAX UNITS NOTES
Modulation Bandwidth 2 3 MHz Sinewave
Rise/Fall Time 250 / 200 nsec To full scale
Slew Rate 30 V / sec
Depth of Modulation 90 % At 500 kHz
Input Impedance 1 k 
External Modulation Input
Damage Threshold -10 to +10 V BNC Connector
MONITORS AND OUTPUTS VALUE UNIT NOTES
Setpoint Resolution 16 bits 5V = fullscale output
Display Accuracy Measurement
Resolution 24 Bits
Accuracy, Current Output
Monitor vs. Actual Current
(display or analog output)
0.2 % > 5% of full scale
0.5 % < 5% of full scale
Accuracy, Current Setpoint vs.
Actual Current 0.2 % Internal setpoint
0.2 % External modulation
Accuracy, Analog Setpoint
Monitor15 % >10% of full scale
25 % <10% of full scale
1Current Setpoint Monitor is a reference signal only, and may deviate from the actual setpoint by up to 5% when the setpoint is greater
than 10% of full scale.
CONTINUED ON FOLLOWING PAGE

8
POWER SUPPLY
REQUIREMENTS VALUE NOTES
AC Power Supply and Line
Frequency 100-120 / 220-240 VAC, 2 A, 50-60 Hz Switch selectable: 100-120 V and 220-240 V, appropriate power cord supplied
Fuse for 220-240 V 0.63 A, 250 V, fast blow 5 x 20 mm, Part #0217.630MXP, Littelfuse
Fuse for 100-120 V 1.25 A, 250 V, fast blow 5 x 20 mm, Part #02351.25HXP, Littelfuse
Power Consumption 9.8 Watts at idle, no output to QCL load
GENERAL SPECIFICATIONS VALUE NOTES
Warm-up Time 1 Hour
Remote Interface USB, Ethernet
Warranty One (1) Year
Safety Tested To IEC 61000-3-2
IEC 61000-3-3
IEC 61000-4-2
IEC 61000-4-3
IEC 61000-4-4
IEC 61000-4-5
IEC 61000-4-6
IEC 61000-4-8
IEC 61010-1
European Council Directive 2004/108/EC &
European Council Directive 2006/95/EC
ABSOLUTE MAXIMUM
RATINGS VALUE UNIT NOTES
Case Operating Temperature
Range -40 to 50 °C
Humidity 80 % Relative humidity at 30°C (non-condensing)
Weight 12 (~5.4) lbs (kg)
Size 3.47 x 8.86 x 17.72
(89 x 226 x 450) inches (mm)

9
OPERATING INSTRUCTIONS (STAND-ALONE)
WHAT’S IN THE BOX
• QCL Instrument
• Power Cable, type appropriate for final location
• Red fuse tray
• Two 0.63 Afuses and two 1.25Afuses for fuse box on the
back panel
• USB Flash Drive, includes all necessary software,
instrument documentation, and additional storage space
• Keys for the key switch
• Interlock Replacement Kit (interlocks for QCL D-SUB and
Active Interlock BNC)
THEORY OF OPERATION
The QCL Series low noise drivers are designed expressly to
drive quantum cascade lasers, and utilize patented1circuitry
to deliver ultra-low noise current and still maintain a wide
modulation bandwidth.
The QCL drivers are controlled current sources; they deliver
the current commanded by the setpoint. The current source
continually monitors the actual output current, compares it to
the setpoint, and adjusts the current if there is a difference
between the two signals.
As current is driven through the load, there is a voltage drop
acrossthe loadproportionalto theloadresistanceandcurrent.
As the current increases, the voltage drop may increase to
the point that it reaches the Compliance Voltage limit of the
current source. Once that occurs the current source is no
longer able to increase the current driven to the load even if
you increase the setpoint.
The QCL driver includes features that help protect your laser,
and also make the driver more versatile in a wide array of
applications. These features are explained in detail in the
Operating Instructions.
• The user-adjustable current limit prevents overdriving the
laser even if the external modulation signal is above the
maximum drive current for the laser.
• Over- and under-voltage protection circuits protect the
driver and QCLif the power supply voltages fall outside of
the acceptable operating range.
• Over-temperature protection circuits safely shut down
the output if the internal temperature of the QCL driver
rises to an unsafe level. The fan turns on to manage the
internal temperature.
• Output slow-start ramps the current to setpoint over
1.5 msec.
• A mechanical relay shorts the output connections when
the output is disabled, and when the QCL driver is
powered off.
1Covered by U.S. Patents 6,696,887; 6,867,644 and
7,176,755. Licensed from Battelle Memorial Institute.
These instructions are for operating the QCL Laboratory
Series instrument. Fuses are provided but not installed. After
installing the fuses in the fuse box, be sure to install the fuse
box so the correct voltage for your country is showing. We
also recommend using a test load until you are familiar with
operation of the instrument.
REQUIRED AND OPTIONAL
EQUIPMENT
FOR SET UP
• Small, narrow headed flathead screwdriver (required)
• Test load (optional)
• Wavelength Interlock Replacement Kit with interlock
overrides (optional)
COMPUTER REQUIREMENTS FOR
REMOTE OPERATION ONLY (OPTIONAL)
Hardware
• 1 GHz or faster 32-bit (x86) OR 64-bit (x64) processor
• 1 GB RAM 32-bit or 2 GB RAM 64-bit
• 16 GB available hard disk space for 32-bit or 20 GB for
64-bit DirectX 9 graphics device with WDDM 1.0 or higher
driver
Software
• Windows 8, 7 SP1, or Vista SP2 Operating System 4.5
.NET framework
ESD INFORMATION
Before proceeding, it is critical that you take precautions to
prevent electrostatic discharge (ESD) damage to the load.
ESD damage can result from improper handling of sensitive
electronics, and is easily preventable with simple precautions.

10
REAR PANEL
ETHERNETUSB
QCL
CHASSIS
GND QCL
MONITORS
SERIAL #
TRIGGEREXT
MOD ACTIVE LOCK
FUSE ~250V, 1.25AF (5 x 20mm)
100-120 VAC, 1.25 A, 50-60 Hz
WARNING: Before powering on
device, verify voltage setting is
correct and proper fuses are
installed.
CAUTION:
No user serviceable parts. Do
not remove cover.
Covered by U.S. Patents:
6,696,887
6,867,644
7,176,755
FUSE ~250V, 0.63AF (5 x 20mm)
220-240 VAC, 0.63 A, 50-60 Hz
!
1
2
35810
9
67
4
13
12
11
Figure 9. Rear Panel
Table 3. Rear Panel Functions
NAME DESCRIPTION
1 Fan Vent Do not block air flow.
2 Chassis Ground Physical connection to chassis and electrical earth ground.
3 QCL SMA SMA connector, alternate connection to QCL.
4 QCL D-SUB 9-Pin female D-SUB connector.
5 Monitors 9-Pin male D-SUB connector.
6 USB USB port, connection between instrument and a computer.
7 Ethernet Ethernet port, connection between instrument and a computer or network.
8 EXT MOD External Modulation: BNC connector, setpoint signal generator input.
9 Active Lock BNC connector, active interlock, tie center pin to GND to enable output.
10 Trigger BNC connector output, allows instrument to trigger external device for synchronizing
measurement.
11 Fuse Box and Voltage
Selector Removable fuse drawer allows user to switch between 115 V and 230 V. Fuses need to be installed prior to operation.
12 Power Switch AC power switch that powers the instrument.
13 Power Plug IEC AC line input.

11
INSTALL FUSES AND SELECT
PROPER VOLTAGE
Figure 10. Fuse Box and Voltage Selector
1. On the back panel, locate the Fuse Box and Voltage
Selector receptacle. (See the Rear Panel diagram on
page 10 for the location.)
2. Insert a small flathead screwdriver into the slot (1) at the
top of the receptacle and twist to open faceplate. The red
fuse drawer and fuses are located in the Ship Kit.
3. On the face of the fuse drawer are two voltage choices.
Based on your country, select the proper fuses to install.
VOLTAGE FUSE PART NUMBER
100-120 V 1.25 A, 250 V,
fast blow Littelfuse 5 x 20 mm,
Part #02351.25HXP
220-240 V 0.63 A, 250 V,
fast blow Littelfuse 5 x 20 mm,
Part #0217.630MXP
CAUTION: It is imperative that the correct voltage
is used. Serious damage can occur if the incorrect
voltage is selected.
4. Insert the fuses as shown in Figure 11, with a short fuse
at the contact end of the receptacle. Then, turn the drawer
until the correct voltage label is at the top and replace it
in the receptacle. Press firmly to make sure the drawer is
completely seated. It should be flush with the receptacle.
Figure 11. Fuse Installation and Voltage Selector
5. Close the faceplate, again pressing firmly until it is flush.
The correct voltage label is shown through the Voltage
Window (2) on the faceplate.
CONNECT POWER
Insert the female end of the IECAC power cord into the Power
receptacle on the back panel and then plug the male end into
the power source.
WIRE ATEST LOAD
Use of a test load is recommended for setup of the QCL
instrument. Use the Wavelength test loads listed on page 1, or
when building your own test load, a 10 resistor with a 50 W
power rating is recommended for the QCL500, QCL1000,
and QCL1500. For the QCL2000, a 50 W 5 resistor is
recommended.
• Install the test load by either connecting to the QCL SMA
port or wiring the load to PIN 5 and PIN 9 on the QCL
D-SUB as shown in Figure 12.
QCL
SMA QCL
1
1 NOTE: The SMA case is electrically connected to the QCL chassis.
QCL D-SUB
6789
12345
Figure 12. QCL Wiring Diagram
-V
Pin 9 QCL +
or SMA Outer Ring
Pin 5 QCL -
or SMA Center Pin
QCL Driver
Current Sink
Test Load
Figure 13. Test Load Polarity Diagram

12
SET UP INTERLOCKS
The Wavelength Interlock Replacement Kit includes a male
D-SUB with the passive interlock pins shorted and a BNC
terminator.
1. For the passive interlock, on the back panel, short PIN 1
and PIN 2 on the QCL D-SUB.
2. For the active interlock, on the back panel, insert a BNC
terminator in the ACTIVE LOCK BNC port.
3. On the front panel, the key switch must be on UNLOCK to
enable the current to the QCL.
NOTE: To disable operation, turn the key switch to the
LOCKED position. The key can only be removed when in the
locked position.
FRONT PANEL
QCL 1 000
LAB
ENABLE
DATA
POWER
1
5
3
2
4
Figure 14. Front Panel
Table 4.
Table 5. Front Panel Functions
NAME DESCRIPTION
1 Power Button Powers the application electronics. Glows blue when application electronics power is on and unit
is operational, slow pulses blue when on Standby and only the back panel power switch is on.
2 Adjustment Knob Turn to adjust the numeric values. Instrument beeps when values are set.
3 Enable Button Allows instrument to deliver current to the QCL. Glows blue when current is enabled.
4 Keylock Switch UNLOCK allows laser output current to flow, LOCK disables laser output current. NOTE: The
key can be removed only in LOCK position.
5 Data Port USB flash drive, used to update the firmware or save data. This is not used for remote USB
control of the instrument.
TEXTAND ICON COLOR KEY
TEXT
Text indicates current state.
White, Green Uneditable field, for information only.
Blue Editable field, touch to select or toggle field
(text highlights and changes color), adjust
using either the touchscreen or adjustment
knob. Instrument beeps and text returns to
blue when values are set. Touch again to
cancel selection.
ICONS
Icon color indicates current state.
Blue Screen is active.
Grey Screen is inactive, touch icon to access that screen.

13
TURN ON QCL INSTRUMENT
1. Press the Power switch on the back panel to |. The front
panel power button light slowly pulses.
2. Press the Power button on the front panel, the button
illuminates, touchscreen is activated, and the Control
screen is active.
NOTE: Turning off front Power button powers down the
application electronics and puts the unit into standby
mode. Turning off rear Power switch powers down all
electronics and settings return to factory default.
3. The front panel displays dashes instead of digits until the
unit has finished its power-up sequence (~10 seconds).
SET LIMITS
1. Press to access the Limit Screen.
2. Press Limit Current, Maximum Supply Voltage, and/or
Cable Resistance values and rotate theAdjustment knob
to change each value. The instrument will beep when set.
Figure 15. Limit Screen
NOTES:
• The Limit Current should not exceed the damage current
threshold of your QCL.
• The Maximum Internal Supply Voltage can be lowered
to minimize internal instrument temperature or to act as a
compliance voltage clamp on the QCLoutput current. See
Additional Technical Notes on page 25 for optimization
instructions.
• The Cable Resistance range is 0 – 1 .
QCL Voltage displays the voltage at the QCL DSUB or
SMA terminals. To account for voltage loss across the
cable to the QCL, you can enter a non-zero value for
Cable Resistance.
The QCL Voltage will now display as:
Voltage Displayed = Voltage@Pins - (Cable Resistance x Operating Current)
• The minimum limit current is about 8% of full scale.
ADJUST THE SETPOINT
1. Press to access the Control Screen.
2. Press the Setpoint value and turn the Adjustment knob
until the desired operating current is displayed.
Figure 16. Control Screen
NOTE: The Control screen is on by default when the
instrument is turned on. The Mode is Constant Current by
default and cannot be changed.
DISPLAY EXISTING CURRENTAND
VOLTAGE VALUES
Press to access the Monitor Screen.
Values on this screen cannot be changed and are for
information only.
Figure 17. Monitor Screen

14
ENABLE THE QCL INSTRUMENT
Press the Enable button on the front panel. The button will
glow blue only when current is delivered to the load. There is
a standard 2-second delay before the button illuminates and
current flows.
VI SCAN
1. On the Control screen, press to access the VI
scan screen.
2. Press the Current Start value to select the current at
which to start the scan. Turn the Adjustment knob to
change it.
Figure 18. Scan Screen
3. Press the Current Stop value to select the current at
which to stop the scan.
4. Press the Step Size value to select the current interval at
which to take a measurement. The maximum interval is
10% of full scale. Minimum step is 1% of full scale.
5. PresstheTime Interval valuetoselect the amountof time
to allow the current to settle. For the best data accuracy,
use a Time Interval of 2 seconds or more. The minimum
time interval is 0.1 seconds.
6. Insert the USB flash drive in the USB slot on the front
panel.
7. Press the green Run button to start the scan. When
finished, data is saved to the USB flash drive with
the filename viscanxx.txt, where xx starts at 00 and
increments.
8. To stop mid-scan, press the red Stop button to abort the
scan. Any data collected during the aborted scan is saved
to the USB flash drive.
NOTES:
• The step interval time is approximate. In the scan files,
time intervals are slightly more than the step interval
indicated on the instrument. Each interval builds on the
previous one.
• ShouldtheStepSizeintervalnotfinishattheStopCurrent,
the reading is still taken and recorded. For example, if
the Start Current is 250 mA and the Stop Current is 1.04
A with a Current Step of 250 mA, a reading is taken at
1000 mA (1 A) and 1040 mA (1. 04A) but not at 1250 mA
(1.25 A).
• After a VI scan is completed, the output is disabled and
the setpoint is zeroed.
SAVE OR RECALL SETTINGS
Press to access the Save/Recall Screen.
Under Save Settings to, press the blue text
to toggle through the Profile options, select
one, and then press the Save icon.
The following variables are saved:
OPERATION SETTINGS VI SCAN SETTINGS
Setpoint VI Start Current
Current Limit VI Stop Current
Max Supply Voltage VI Step Size
Cable Resistance VI Time Interval
Display Brightness
Beeper Status
Figure 19. Save / Recall Screen

15
Under Recall Settings from, press the
blue text to toggle through the saved Profile
options, and then press the Recall icon to
recall the saved settings. Select Factory to
restore the settings to the factory defaults.
SETTINGS SCREEN
Press to access the Settings Screen
Move the slider bar on the touchscreen to change the display
brightness. Press the blue text to toggle the Beeper on-off
setting.
Figure 20. Settings Screen
LOCK OR UNLOCK SETTINGS
(OPTIONAL)
Settings are not locked.
This is the default. Critical values set with the
Adjustment knob can be locked. Press to lock
the settings.
Settings are locked.
Press to unlock the settings.
Settings are locked and password protected.
Locked settings that are password protected
can only be locked and unlocked using a remote
computer.
EXTERNAL MODULATION
(EXT MOD) BNC
This is the external modulation input. The voltage input on
this BNC sums with the DC value on the screen. The input
impedance is 1 k . To calculate the external modulation
signal voltage, see the next section for the transfer function,
and use the following equation:
VEXT_MOD = ISETPOINT / Transfer Function
If the external modulation input causes the driver to reach the
current limit, the output signal will be clamped at the limit level
but will not switch off.
The bandwidth of the Current Monitor is lower than the
bandwidth of the output. To monitor the actual output
waveform at high frequencies, connect an oscilloscope across
the output pin on the MONITOR D-SUB, Pin 8 (positive), and
Pin 9 (ground) while using the resistor test load.
CAUTION: Connect the oscilloscope across the
test load only — never connect the oscilloscope
across a quantum cascade laser.
EXTERNAL MODULATION BNC
TRANSFER FUNCTIONS
The external modulation transfer function depends on the
QCL instrument model and is as follows:
QCL500-LAB: 0.1 A / V.
QCL1000-LAB: 0.2 A / V.
QCL1500-LAB: 0.3 A / V.
QCL2000-LAB: 0.4 A / V.
The input range is always 0 – 5 V.

16
ADDITIONAL CAPABILITIES
ANALOG CURRENT MONITOR
This signal is the sum of the DC setpoint as shown on the
screen and the external modulation input.
To monitor the analog current level:
1. Connect the Analog output Current Monitor (PIN 8) on the
MONITOR D-SUB to an oscilloscope.
2. Connect an Analog Monitor Ground (PIN 7 or PIN 9) to
oscilloscope ground.
SETPOINT CURRENT MONITOR
This is a reference only and can be off by as much as 5%
when setpoint is >10% of full scale.
To monitor the setpoint current:
1.MeasurethevoltageontheAnalogSetpointMonitor(PIN6).
2. Ground for that measurement is theAnalog Monitor Ground
(PIN 7 or PIN 9).
The setpoint monitor and analog current monitor transfer
functions depend on the QCL instrument model and are all
as follows:QCL500-LAB: 0.1 A / V.
QCL1000-LAB: 0.2 A / V.
QCL1500-LAB: 0.3 A / V.
QCL2000-LAB: 0.4 A / V.
The input range is always 0 – 5 V.
ALIGNMENT LED DRIVE
+5 V, up to 250 mA sourced.
To drive an alignment LED, on the MONITOR D-SUB
1. Connect an LED to the Alignment LED +5V (PIN 1).
2. Ground the LED at the Alignment LED Ground (PIN 2).
ENABLE STATUS INDICATOR
This is a +5 V TTL indicator. If current to the QCL output
is enabled, the voltage between PIN 3 and PIN 4 on the
MONITORS D-SUB will be low. It will be high if current is
disabled.

17
OPERATING INSTRUCTIONS (REMOTE)
INSTALL THE LAB QUICKCONNECT
APPLICATION SOFTWARE
The QuickConnect software is necessary for remote operation
of the instrument. The software can be installed on the remote
computer from either the USB flash drive included with your
instrument or from the Wavelength website.
• On the USB flash drive, the software is located in the
\ setup folder.
• On the Wavelength website, the link to the software is
located at
http://www.teamwavelength.com/support/software.php.
http://www.teamwavelength.com/support/software.php.
NOTE: .NET 4.5 software is required to run the application. If
it is not currently installed on the remote computer, it will be
installed automatically when you insert the flash drive.
TO INSTALL THE SOFTWARE,
1. From the USB flash drive or the Wavelength website
and in the file dialog box, select the software version that
corresponds to your computer system type, either 32-bit
or 64-bit. NOTE: If the incorrect system type is selected,
an error message will appear and the software will not
install.
2. Click the computer system’s setupxx.exe file, where “xx”
refers to the system type. The Preparing to Install dialog
box opens and the software automatically extracts the file.
3. On the Welcome window, click Next.
4. On the Destination Folder window, click Next to accept
the default Wavelength folder or Change to select a
different folder. When the new folder has been selected,
click Next.
5. On the Ready to Install window, review the settings, click
Install.
6. On the Windows Security window, click Install.
7. On the Completed window, select the Launch the
program checkbox to open the application and then click
Finish.
UPDATE THE INSTRUMENT
FIRMWARE
Updates to the instrument firmware are available on the
Wavelength website.
1. Turn the instrument completely off at both the front and
rear panels, and then turn it completely on again.
2. On the Wavelength website, download the ZIP file that is
specific to your QCL Laboratory Series model and save
the update file to a flash drive.
The file is found at:
http://www.teamwavelength.com/support/software.php
http://www.teamwavelength.com/support/software.php
3. Extract the file on the flash drive. It should contain the
following files:
\INSTALL.INI
\QCLxx\ABL.IMG
\QCLxx\APP.IMG
\QCLxx\INSTALL.INI
NOTE:“QCLxx”isreplacedwiththeinstrumentmodelnumber,
such as QCL2000.
4. Insert the flash drive into the front DATA port on the
instrument. The update automatically begins installation.
5. AttheApplythefirmware screen,clickYes.Thefirmware
update installs.
6. Once the update is complete, click OK and reboot the
instrument by turning off the front and rear panel power
buttons and turning them back on again.
7. (Optional) To confirm the latest version is installed on
the instrument, after the instrument is on, swipe the
touchscreen to show the system information screen. The
new version number is displayed.
CONNECTAN INSTRUMENT TO A
REMOTE COMPUTER
1. Connect the QCL instrument to a power source. See
the Stand Alone operation instructions on page 11 for
more information.
2. Connect the instrument to the computer using a USB or
Ethernet cable. If connecting more than one instrument, a
USB or Ethernet hub may be required.
3. Turn on the rear panel Power switch. The front panel
Power button pulses blue.
4. Turn on the front panel Power button. The button glows
steadily blue and the touchscreen activates.
ACCESS THE INSTRUMENT ON A
REMOTE COMPUTER
1. On the computer and from the Start Menu, click All
Programs, then click Wavelength Electronics, and then
LAB QuickConnect. The LAB QuickConnectApplication
window opens.
2. In the LAB QuickConnect Application window, click
Open Instrument.
3. In the Choose Instrument To Open window, select the
instrument to connect to and click Open.

18
Figure 20. Include USB Devices window
NOTES:
• The Include USB Devices checkbox is selected by
default and any powered instruments currently connected
to the computer via a USB cable appear in the list.
• If you are unsure which instrument to select, on the
instrument, swipe the touchscreen firmly from left to
right. The instrument details screen, including the serial
number, appears.
• Instruments that are connected to subnets can be added
to the list.
1. Select the Include Network Devices checkbox, add
the IP address or host name of the subnet, and then
click Add Host.
2. Click Refresh. Any instruments connected to that
subnet appear in the list.
Figure 21. Include Network Devices window
3. On the Instrument Operation tab, in the lower left, click
Seize. Control of the instrument will transfer from the
instrument to the computer and a screen of all editable
fields appears. The computer screen is editable and the
instrument screen is not.
NOTE: One instrument can be controlled remotely at a time.
Figure 22. Remote Computer Control screen
Figure 23. Instrument touchscreen when controlled remotely
CHANGE THE TURN-ON DELAY
The default delay between the time the current to the laser
is enabled and the current actually flows is 2 seconds. This
turn-on delay can be set to a minimum of 0 seconds and a
maximum of 5 seconds.
1. On the Operation Tab, click on the blue text below Turn-
On Delay.
2. Change the value and tab to a new editable field to save
the change.
CONTEXTUAL HELP
At any time, contextual Help Information appears on the right
side of the window when the pointer is placed over a button
or screen element. Technical Support information, such as the
instrument serial number and Wavelength contact information
is available when the pointer is placed over the grey frame
surrounding the window.

19
SUPER USER VS. NORMAL USER
PERMISSIONS
There are two levels of permissions when modifying the
instrument controls, Super User and Normal User.
Super User: The Super User has the ability to modify any
remote operation and to assign permissions for Normal
Users.A password is required to access Super User features.
Upon first sign in, the password entered is the new Super
User password and is required for subsequent sign ins.
Normal User: The Normal User is primarily used for Local
operation. The Super User can restrict access to specific
inputs on the instrument.
ACCESS SUPER USER MODE
When control of the instrument is first seized, it is in Normal
User mode.
1. On the Instrument Operation tab and at the bottom, click
Super User.
2. Type the password in the text box and click OK. Select
the Show Password checkbox to type the password as
text.
NOTE: Upon first sign in, the password typed becomes the
password for subsequent sign ins.
Figure 24. Enter Password window
EDIT INSTRUMENT PROFILES
Profiles can be edited in Super User mode or when Normal
Users are not restricted from saving profiles.
1. In the Profile Editor Window and in the Available
Profiles menu, select a profile. The factory default profile,
Profile 0: Factory Default, cannot be changed.
2. Type values in the Profile Data boxes.
3. (Optional) In the Description Line 1 and 2, type a
description of the profile. This text replaces the Save-
Recall Profile text on the instrument. A maximum of 14
characters are saved.
4. (Optional) To grant Normal Users read-write permissions,
select the appropriate checkbox.
• Local User Can Save/Modify This Profile: Allows
any user to change any preset profile value on the
instrument.
• Normal User Can Recall: Allows any user to recall
preset profiles. This is selected by default.
5. Click Apply to Instrument and/or Save.
• Click Apply to Instrument to change the values
on the instrument but not save the changes to the
Profile.
• Click Save to save changes to the Profile but not
change the values on the instrument.
• Click Apply to Instrument and then Save, to apply
changesto theinstrumentand thensave thechanges
to the Profile.
6. . Figure 25. QCL-LAB Profile Editor window

20
EDITADVANCED OPTIONS
Advanced Options can only be edited in Super User mode.
Figure 26. Advanced Options window
CHANGE PERMISSIONS
Permissions can only be modified in Super User mode and
apply only to Normal User mode.
1. Under Permissions, select Apply Restrictions To
Instrument.
NOTE: To apply the restriction changes to the instrument,
this checkbox must be selected when the selections are
saved.
2. Selecttheappropriate checkboxtorestrictaccess tothose
values. Click All to select all the checkboxes or None to
clear them. All restrictions apply to Normal Users when
the instrument is in Normal User mode or when operated
in local mode.
3. Click Save.
NOTES:
• Restrictions checkboxes can be selected and saved
without applying the changes to the instrument.
• To apply the local Save Profile and Recall Profile
options to the instrument, the local user Save/Modify and
Recall checkboxes on the Profile Editor must also be
checked, as well as the Apply Restrictions checkbox on
the Advanced Options dialog box.
CHANGE SUPER USER PASSWORD
1. On the Instrument Operation tab, click Super User.
2. Type the password in the text box and click OK. Select
the Show Password checkbox to type the password as
text.
3. Under Permissions, click Change Super User
Password.
4. Type a new password and then click OK.
CHANGE NETWORK
CONFIGURATION SETTINGS
Network configurations can only be changed in Super User
mode.
1. Under Network Configurations, click Edit Network
Configuration.
2. Type the new information into the text boxes and click
Save.
POWER INSTRUMENT ON OR OFF
The front panel can be turned on or off using a remote
computer. When the front panel Power button is turned on,
the button displays a blue circle and the screen displays all
editable values on the instrument. When it is turned off, the
screen is black and only the Power button, without the blue
circle, is available. This is equivalent to pressing the front
panel Power button.
• OntheInstrument Operationtab,clickthe Powerbutton.
Figure 27. Power button on Figure 28. Power button off