I checked the IMC REFL demod phase. Locking the IMC was very easy- with 100 mW coming from the PSL, I selected "locked" on the guardian and it locked right away, good work from the team in alog 89106!

I injected a 400 ct line into IMC L at 50 Hz, following similar steps done by the JAC crew here.

I only saw the line in I phase, so I tried taking a no injection reference and also bumping up the injection to 800 ct to see if there is signal in Q phase. There is no visible signal in Q phase. Therefore, I declare that the IMC refl demod phase is just fine at 20.87 deg.

The attached plot shows the injection time in the red and blue live traces in I and Q, and the no injection reference time in pink and blue.

I ran another excitation at 10000 ct to generate the second plot attached.