Yuhang, Marc, Matteo

The main laser phase modulation introduces phase noise for squeezing measurement. This phase modulation is reduced from DDS setting by a factor of 4. Before and after this modulation reduction, we measured squeezing level. The result of squeezing measurement is shown in the attached figures.

Since there are peaks appearing in the squeezing measurement, to compare measuremet in a fair manner, I did an average of data from 9.6kHz to 16kHz for each measurement separately. We see that the squeezing level differs by 0.2dB, it seems that this gain of 0.2dB could come from the reduction of phase noise. To confirm this phase noise, we would make a squeezing measurement at a higher pump power situation (the current measurement used 40mW pump with 4.5 MZ offset). CC1 pk-pk was 41.2mW