Attachment 1: PDH error signal with monitor flashes

Using the setup shown in Attachment 3 (diagram here) (cavity design here), where the RF output of the free-space 1811 photodiode is sent to a Level 17 mixer ZFM-3H-S+ and then to a low pass filter SLP-1.9+ (cut-off at 1.9 MHz), I observed the PDH error signal on an oscilloscope while scanning the temperature.

Attachment 4 is a single-shot measurement of the error signal.

EOM: MPX-LN-0.1 driven with -5.8 dBm at 33.59 MHz using the OCXO pre-amp EOM output at 30 dBm attenuation.

LO: Driven at 33.59 MHz using the LO output of the OCXO pre-amp with no attenuation, estimated to be ~13.8 dBm.

The power levels of the OXCO outputs were the peak powers calculated by the Moku while observing the spectrum. The Moku itself produces a lot of distortion (many prominent harmonics were seen) while measuring this spectrum, these harmonics were less prominent when the scale was changed or when the input was attenuated sufficiently.

Attachment 2:

Picture of beat note measurement between North and Teraxion requested by Rana.