Last update: 2021/12/17 00:00
d2:laser_controller https://www.vescent.com/manuals/doku.php?id=d2:laser_controller
https://www.vescent.com/manuals/
Printed on 2021/12/18 07:41
stage 1 does not have an equivalent function. Stage 2 is accessed in the middle of the side-panel,
while stage 1 is near the back of the side panel. Typically, stage 2 is used to control the laser
temperature and stage 1 is used to control the temperature surrounding stage 2. In this way
temperature gradients between the laser diode and the thermistor measuring the laser temperature
are stabilized and temperature changes caused by room temperature drift are greatly reduced.
Transfer Function and Poles
Each stage of temperature control has a transfer function shown below:
The two poles (ω
1
and ω
2
) and the overall gain can be adjusted using trimpots and click-switches on
the side panel. The first pole (ω
1
) is the Proportional-Integrator (PI) pole, or the frequency where the
gain switches from being an integrator to proportional. The second pole (ω
2
) is the Differential (D)
pole, or the frequency where the gain becomes differential. The final (non-adjustable) pole (ω
3
) is
where the differential gain ends and the gain becomes proportional again and is internally set to
twenty-five times ω
2
.
