Pigtailed Laser Mount
Chapter 7: Troubleshooting
Page 18
TTN027954-D02
Troubleshooting
If you are using Thorlabs’ Laser controller with your LDM9LP:
Possible Solution
Directions
Remote interlock is
open
Make sure that either the shorting device is installed in the
REMOTE INTRLK connector on the side of the LDM9LP.
If you have a remote interlock switch connected to this
REMOTE INTRLK connector, it must be in a closed
position.
Laser Driver will not
Enable
Make sure the Remote Interlock is closed. Check the laser
diode polarity and make sure the polarity switches on the
mount are set correctly.
Laser Wavelength or Power is Unstable
Possible Solution
Directions
LD is not fully seated
Make sure your laser pigtail is fully inserted into the
LDM9LP laser socket and its body is in full contact with
the copper cold plate.
LD is mode hopping
The laser pigtail may be operating on a mode transition.
Try adjusting the temperature to shift the laser diode to a
more stable operating point.
The LDC Series Laser Driver Indicates an “Open Circuit” Alarm When You
Try to Enable the Laser
Possible Solution
Directions
LD and PD polarity
switch settings are
incorrect
Refer to Figure 2 and the data sheet for your specific diode
to ensure the proper settings. The LD polarity switch
setting on the mount must match the LD polarity switch
setting on the rear panel of your LDC series laser diode
controller.
LD orientation may be
incorrect in the socket
Refer to Figure 1 and the laser pigtail data sheet for you
specific diode to ensure proper orientation.
TEC lockout circuit is
active and the TED
Series TEC controller is
not enabled
To determine if you have selected the TEC Lockout circuit
to be active, refer to 3.7 and Figure 7. If it is selected, then
the TED Series TEC controller must be enabled first
before the LDC Series laser controller can be enabled.
If you still have problems or questions regarding the operation of your LDM9LP,
please feel free to call Thorlabs and ask for Technical Support.
