© 2019 Thorlabs
3 Operating Instructions
14
3.2.13 Analog Output
PM101A
The PM101A has an analog output port with a SMA output connector.
This analog output, similar to the AO2 port of the PM101, delivers a range independent voltage
which is DAC controlled. The output voltage is proportional to a configured value in V/W. This
constant can be adjusted via the OPM software or the SCPI/driver commands for custom made
software. The constant can be set in the OPM software under the Settings tab: AO Responsivi-
ty. The analog signal is generated with a 16-bit DAC with an update rate of 1 kHz. The analog
output voltage can range from -0 V to +2.5 V.
The analog signal following the DAC is of advantage when large signal dynamics are expected
because the DAC range changes and the output signal stays largely the same. Additionally, the
output signal is wavelength corrected and corrected regarding the sensor calibration data.
PM101
The PM101 has two analog outputs, AO1 and AO2.
The Analog Output ports
provide the amplified photo-diode current or the amplified thermal
sensor voltage, depending on the sensor. The signals from the analog output AO1 are not
wavelength- or zero- corrected.
The signal is measurement range dependent and can be calculated to:
AO1
: The AO1 (DA-15 Pin 4) delivers the amplified direct
real analog signal
without a Digital-
Analog-Converter (DAC). Therefore, the AO1 delivers a proportional voltage for each measure-
ment range. The analog output voltage can range from -0.25 V to +2.5 V. The bandwidth is ac-
cording the setting of the meter. The advantage of this real analog signal is its speed (up to
100kHz).The Analog Output Port is not wavelength- or zero- corrected.
AO2
: The AO2 (DA-15 Pin 5) delivers a range independent voltage which is
DAC controlled
.
The output voltage is proportional to a configured value in V/W. This constant can be adjusted
via the OPM software or the SCPI/driver commands for custom made software. The constant
can be set in the Thorlabs software OPM under the Settings tab: AO2 Responsivity. The signal
of the AO2 is generated with a 16-bit DAC with an update rate of 1 kHz. The analog output
voltage can range from -0 V to +2.5 V.
The analog signal following the DAC is of advantage when large signal dynamics are expected
because the DAC range changes and the output signal stays largely the same.
3.2.14 Autonomous Operation to Analog Output
Power meters PM101 and PM101A can be run autonomously by only connecting a power sup-
ply and using analog output. In that case, no control device is required. For the PM101, both
analog output ports can be used for autonomous operation.
