© 2018 Thorlabs
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ITC4000 Series
3.6 Setting the Power Feedback Source Parameters
To select the power feedback source please refer to section
Setting the LD source paramet-
. Additional settings according to the selected sensor are described in the following two
sub items.
3.6.1 Photodiode Input
For current sensors like photodiodes the following parameters can be set:
Parameter
Selection
Description
Polarity
CG or AG
grounding of the used photodiode:
CG: cathode grounded
AG: anode grounded
Input Route
DSUB connector or Rear Panel
BNC
configures which input connector is
used
Range
2mA or 20mA
depending on nominal current of the
used photodiode
BIAS State
On or Off
an applied reverse bias voltage is
used to reduce the response time of
the photodiode
BIAS Voltage
0 to ±10 V
reverse bias voltage value.
The sign is depending on the selected
polarity
Response
entered in mA/W
is used to display a calibrated power
value
For using photodiode sensors in the constant power loop please choose photodiode input as
power feedback source (please refer to section
Setting the LD source parameters
)
.
Polarity:
The polarity in the Photodiode Input configuration menu can be chosen between anode groun-
ded (AG) and cathode grounded (CG). For connecting the photodiode please refer to section
Attention
Take care to select the proper polarity of the connected photodiode. A wrong polarity may dam-
age the photodiode, if a bias voltage is applied.
Input Route:
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