3. Measuring with the OPX+

Configuration

The oscilloscope is replaced by the photo-diode. This time, we don’t use an output port but an input port of the OPX+. We create a measurement pulse that will only acquire data. We connect to this pulse a post-processing tool integration with integration_weights \(\frac{1}{t_{meas}}\) with \(t_{meas}\) the duration of the measurement. Output port 1 of OPX+ is still connected to the AOM.

Program

The program measures the intensity received by the photo-diode for various amplitudes of the RF pulse sent to the AOM. These amplitudes range from 0V to 0.5V with steps 0.00025V. For each amplitude, the experiment starts by sending a RF pulse to the AOM. 120ns later, we start measuring the photo-diode. This measure lasts \(10\mu s\). When it is over, the signal is averaged using integration: the amplitudes are summed and divided by the acquisition time. The output is saved in the variable i.