Measure FIS at 25mW and 40mW after clean some optics

7/28 [Chien-Ming and Hsun-Chung]
At first, the SHG is 119.7mW in front of MZ.
We correct the HOM DC balanced from -10mV to 0mV by fine-tuning HOM BS Yaw.

Hsun-Chung bought some glass dropper bottles to hold acetone (buy from HANDS).
We cleaned some optics on the optical path of HOM and SQ and then checked the BAB alignment at AMC.
TEM00=206mV; hom=5.6mV+5.6mV; mode-matching:94.8%

In the beginning, the OPO T was 7.117k(p-pol is 270MHz) with pump 25mW, the BAB max=52mV, min=24mV.
After setting the OPO T to 7.159k(p-pol is 270MHz), the BAB max= 952mV, min= 104mV
At the 25mW green pump, we measured 4.47dB squeezing and 8.43dB anti-squeezing which is worse than yesterday's result.
Therefore, those optics may not be cleaned well.

Then we measured twice FIS at the 40mW pump, got 5.28dB SQ and 12.13dB Anti-SQ at first, and 5.29dB SQ and 11.65dB ASQ at second.
Before the second measurement, the MZ failed to lock again. The reason is that the output power of the SHG seems insufficient (100mW in front of MZ).
By setting the temperature of SHG from 3.158k to 3.123k, the green light in front of MZ becomes 194.9mW.
The BAB max=1.54V and min=152mV at 40mW pump and OPO T= 7.182k (p-pol is 270MHz).
Without green pump, the BAB=234mV at OPO T=7.121k (p-pol is still 270MHz)
Therefore, the nonlinear gain is 6.58 at the 40mW pump.

The attachment is the comparison of the measurement data for two days