NAOJ GW Elog Logbook 3.2
Yuhang and Yaochin
Firstly, we checked the amplification of BAB with 60mW. The factor is around 30. While the characterization we did last year shows amplification of roughly 60.
Then we measured SQZ and ASQZ at different green power
Green power(mW) |
OPO T (kOhm) |
PLL-pol (MHz) |
CC1 error signal pk-pk (mV) |
CC2 demodulation phase (SQZ) |
CC2 demodulation phase (ASQZ) |
60mW |
7.23 |
170 |
49.2 |
124 |
130 |
55mW |
7.227 |
170 |
40 |
118 |
138 |
50mW |
7.217 |
170 |
37.5 |
115 |
139 |
45mW |
7.211 |
170 |
31.2 |
110 |
145 |
40mW |
7.205 |
175 |
30.8 |
110 |
150 |
35mW |
7.201 |
180 |
26.4 |
105 |
155 |
30mW |
7.196 |
185 |
23.2 |
100 |
155 |
25mW |
7.189 |
185 |
21.6 |
90 |
155 |
From the above data, loss is 25.1% and phase noise is 19.4mrad. The loss is consistent with Aritomi-san's result. While the phase noise is a bit reduced.
We also measured the CC2 phase noise. The measurement is done with a 40mW green power and 110deg CC2 demodulation phase. Then we got CC2 pk-pk 62.4mV. We use this for calibration and got a phase noise of 4.25mrad.