2.7 Polarity of the laser diode (LD POL)
ITC500 / page 36
2.7 Polarity of the laser diode (LD POL)
The laser diode can either be operated with anode or cathode connected to ground.
If you have chosen the right pins of the output jack, you also have to select the right
polarity with the button
LD POL
in the field SETUP at the front panel.
AG
means laser diode anode is connected to ground.
CG
means laser diode cathode is connected to ground.
The corresponding LED indicates the selection.
2.8 Polarity of the monitor diode (PD POL)
The monitor diode can either be operated with anode or cathode connected to
ground. If you have chosen the right pins of the output jack, you also have to select
the right polarity with the button
PD POL
in the field SETUP at the front panel.
If the polarity has been chosen correctly the display of the photo current is positive.
If the chosen polarity is wrong the display of the photo current is negative when
driving the laser diode above the threshold current. In this case you
must never
switch on the bias voltage.
2.9 Bias voltage of the monitor diode (BIAS)
If required the monitor diode may be driven with a bias voltage of 0 ... 10 V.
By pressing the button
PD POL
again the bias voltage is in standby, indicated by the
LED
BIAS
in the field SETUP at the front panel. The LED
PRESET
indicates that the
bias voltage is switched on and off simultaneously with the laser diode current. When
the bias voltage is present, the LED
PRESET
extinguishes.
Summary of Contents for ITC502
Page 2: ...Version 2 16 Date 25 07 2006 Copyright 2006 Thorlabs ...
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