Daniel, Terry, Haocun, Nutsinee

CLF

The furthest I can push the UGF was 6kHz. This gave us a gain margin of ~30deg. You can push to 8 but then gain margin drops to 10deg. 

LO

We closed the LO loop for the first time last Friday. Homodyne seemed to have a lot of RF gain. We were hitting it with no more than 200uW of optical power (CLF+LO combined) and it was already producing 6MHz harmonics straight out of the box. To get rid of the harmonics we are now hitting it with 157uW combined optical power (17uW CLF, 140uW LO). Homodyne RF characterization will be posted in a separate alog.

The UGF was around 2kHz with ~40deg phase margin. This cannot be pushed further because of the huge peak around 34kHz that's believed to be LO PZT. To see if current loop configuration is good enough we'll have to look at the noise spectrum out of the error signal when the HD is well balanced. Currently we seems to have a beam splitter that drifts over night in front of the HD.