Eleonora and Yuhang

Today we tried to monitor detuning drift but filter cavity always got unlock(almost every 5 minutes). And we noticed that the length correction signal was always drifting. Considering the change of 3000counts, we can convert it to the voltage we send to laser PZT is drifting by about 3.66V(3000count/1000count*0.61V*(100/50)).  Maybe it drifts out of range and made filter cavity unlock. However, from the manual of laser, the PZT driving coefficient is 1MHz/V. And the PZT driving range is +/-65MHz. It seems they are not consistent.

Besides, the reason for this correction drift is till under investigation.