THORLABS ITC4000 Series, Руководство по эксплуатации

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3 Operating the ITC4000 Series
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depth). With an oscilloscope connected to the ANALOG CTL OUT jack, the resulting waveform
can be evaluated. Increasing the feedback loop speed as long as no overshoots are visible at
the square wave, should result in an optimized setup. When using a thermopile sensor, a quite
slow feedback loop speed may be necessary to obtain a stable constant power control.
3.5 LD Source Setpoints
You can change the set point values for constant current or constant power mode depending
on the selected operating mode. To select the operating mode please refer to section
Setting
the LD source parameters .
For constant current mode, only the laser current can be adjusted. This value can also be
changed from the measurement screen, if one of the displayed values is the laser current set
point.
In constant power mode you can adjust the photodiode current or the thermopile voltage de-
pending on the power feedback source selected in section
Setting the LD source parameters
. If you have entered the response of your feedback source in mA/W (photodiode) or mV/W
(thermopile) you can use the optical power set point to change the optical output power.
Note
In constant current mode, the constant power mode set points are ignored. In constant power
mode, the laser current set point is ignored. Only the set point for the selected power feedback
source will be effective.
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