Michael and Yuhang

It was found that the detuning change is highly related with the correction signal sent to main laser when filter cavity is controlled with GR (elog2636).

To confirm this effect, we sent a sinusoidal signal to main laser temperature which can change main laser frequency up to few GHZ. After that, we collected the data of filter cavity end mirror z_corr, fc__ir_tra, and fc_ir_detuning.

Using the same method as elog2636 but the calibration factor from correction signal to length is from elog2606 because the control loop gain needs to be considered.  Then we get cavity correction signal and detuning change as attached figures. This proves again the detuning change caused by the presence of AOM.