NAOJ GW Elog Logbook 3.2
In this measurement, PR pointing loop was used instead of BS pointing. The detuning fluctuation is still ~10Hz.
sqz_dB = 10.7; % produced SQZ (dB)
L_rt = 120e-6; % FC losses
L_inj = 0.31; % Injection losses
L_ro = 0.24; % Readout losses
A0 = 0.05; % Squeezer/filter cavity mode mismatch
C0 = 0.05; % Squeezer/local oscillator mode mismatch
ERR_L = 1e-12; % Lock accuracy (m)
ERR_csi = 30e-3; % Phase noise (rad)
Note: In this calculation, shot noise level is assumed to be -133.2 dBVrms/rtHz, but actually it was -133.7 dBVrms/rtHz. So the result in this log is wrong...
I analyzed again with correct shot noise level (-133.7dBVrms/rtHz) and 12% loss from visibility. The readout loss includes 12% loss from visibility, 2% loss from homodyne (dark noise, quantum efficiency, AR), and 20% loss from pick off BS.
sqz_dB = 11.8; % produced SQZ (dB)
L_rt = 120e-6; % FC losses
L_inj = 0.32; % Injection losses
L_ro = 0.31; % Readout losses
A0 = 0.05; % Squeezer/filter cavity mode mismatch
C0 = 0.06; % Squeezer/local oscillator mode mismatch
ERR_L = 1e-12; % Lock accuracy (m)
ERR_csi = 30e-3; % Phase noise (rad)
Yuhang and Michael fitted this data with mcmc. However, the detuning fluctuation is larger than that with least square... In this fit, the fit has been started from 60Hz and the detuning fluctuation could be smaller with higher fit starting frequency.
Left: mcmc (detuning: 50-68 Hz)
Right: least square (detuning: 49-61 Hz)