| I changed the 1/2 wave plate from the lens mount to the rotational optic mount. This allowed me to rotate the 1/2 wave plate, which changed the respective polarization power transmitting through S and P polarization. Initially, more power was coupled into the P polarization. Now, with the 1/2 plate rotated, both channels are experiencing the same voltage reading. Before feeding the PDA signals into the red pitaya, a 50 ohm terminator had to be placed at the SMA connection port so that the input power into the red pitaya did not exceed 1V. With this configuration, both channels experience about 0.35mV. (See attached)
I then opened the Jupyter notebook, and ran a demo time series measurement from the red pitaya. This time, I was able to get a plot featuring both channels (green is P polarization. Blue is S polarization). The plots are consistent with what is shown in the red pitaya oscilloscope. However, the time collection (I'm assuming) only runs for about 0.018s. I will have to write some of my own code to loop over this measurement, and collect more data. |