Quantum Instruments Cascade Laser Starter Kit - Manual (Page 37)

Starter Kit Instruction Manual Troubleshooting 36
Laser draws current but gives no
light
- The laser may be reversed polarized (it
is not a desirable situation but does gen-
erally not destroy the laser).
√
Check the polarity of the connection.
- The polarity is right. It draws too much
current and the power meter is misaligned.
√
Reduce the current at the maximum
specified for the operating temperature.
√
Check power meter alignement and
scale.
- The QCL laser is not used with the LLH
and is grounded.
√
Check that there is no short-circuit on
the circuit.
The laser does not draw current
- There is no contact with the laser.
√
Check that the gilded copper contact
is present and properly mounted.
√
Tighten the PET U-shaped holder in
order to effective the contact with the
laser by means of the POM fixing screws.
√
Check the connections on the LLH.
Measure the input resistance with an ohm-
meter between the Laser connector and
the Base receptacle connector.