THORLABS ITC4000 Series, Руководство по эксплуатации

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ITC4000 Series
urement lines. The Laser current lines should be as short as possible and as close together as
possible (e.g. twisted) to minimize inductance.
3.1.2 Connecting the Laser Diode
For CG polarity connect the laser diode with anode to A3 and with cathode to A1 (ground). For
AG polarity, connect the laser diode with cathode to A2 and with anode to A1 (ground). Please
refer to section
Pin assignment of the laser output jack .
Attention
Take care to select the proper polarity for the connected laser diode. A wrong polarity
may damage the laser diode.
We recommend using separate shielded lines drilled in pairs (twisted pair) for laser diode cur-
rent and laser voltage measurement, as well as for the sensor inputs.
Some laser modules have a common ground pin for laser and photodiode. Figure 6 shows four
wiring configurations for these modules.
Connecting combined laser diode and photodiode modules
3.1.3 Connecting an Optical Sensor as a Feedback Source
The ITC4000 Laser Diode Controllers support optical current sensors (e.g. photodiodes) and
optical voltage sensors (e.g. thermopiles) for monitoring the laser power output. Both sensor
types can be used as a feedback source for a constant power loop to stabilize the laser output
power.
3.1.3.1 Connecting a photodiode
The photodiode input circuit design is a trans-impedance amplifier with virtual ground (input im-
pedance ~0
W
).
The photodiode can be connected to the 13W3 DSUB jack "LASER OUTPUT" (R9) pins 7 and
8 or to the BNC jack "OPT SENSOR IN" (R4) at the rear panel of the ITC4000 (please refer to
section
Operating elements at the rear panel ).
For more information about connecting modules with common laser and photodiode ground
please refer to section
Connecting the Laser Diode
The photodiode input parameters like input route, polarity, current range, BIAS state, BIAS
voltage and response can be set via
Setting the Photodiode Input Parameters .
We recommend using shielded “twisted pair“ wiring for the monitor diode current measurement.
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