Participaint: Eleonora and Yuhang

We convert BAB into p-pol and then measured the beat between it and the LO at the homodybne BS.

The result is shown in the attached picture. The visibility is (Vmax-Vmin)/(Vmax+Vmin) = (4.26-1.26)/(4.26+1.26) = 0.5435

The BAB power is 0.125mW and LO power is 1.24mW. The expected visibility is 2*sqrt(P1*P2)/(P1+P2) = 0.5768

So from these values, we should have 0.5435/0.5768 = 94.22% of matching of two beams. This is complaint with the matching we measured before.

There is one thing block us from measuring visibility, it is the use of lenses. Before we used lense, we can see the beam is flashing but cannot see this signal on oscilloscope.

By considering the level of visibility, I did the simulation of degradation. As shown in the attached figure two. Now because of only the reason of visibility, we degrade squeezing by 2.74dB.(I assume here the initial squeezing level is -10dB, the degradation is different for different initial squeezing level)