Sheila, Daniel, Nutsinee

Quick report on the homodyne recovery. 

It's squeezing!

We observed ~5dB of squeezing and ~8.7dB of anti-squeezing at non linear gain of 3.8.

7mW was sent to the OPO (refl readback before OPO locked). 2.6mW transmitted (during OPO locked).

Fringe Visibility was 97.5% on PD2 and 98% on PD1. The Homodyne was balanced with 0.5mW PSL LO into each diode (1mW LO total). We had about 20dB of clearance from dark noise.

We made sure that every loop has reasonable phase margin. OPO UGF was 1.2kHz, CLF UGF was 3.6kHz, and LO UGF was 17.8kHz (homodyne locking). 

The phase noise is high likely due to the roughing pump running next to SQZT6 (if we trust the fit with single data point at all). We will take more measurements later when it's more quiet out there. 

The 80MHz VCO servo ran away causing trouble locking LO loop (probably gave me trouble with the fringe visibility earlier too as homodyne response is frequency dependent). Something to keep an eye out for next time. 

The sqz noise at f>10kHz could be due to us changing CLF phase without keeping track of how well the LO was locked. The squeezing trace was responding to the CLF phase delay changes so LO was at least locked (somewhat). This could easily be another source of phase noise.