Pierre, Yuhang

We had some problem with implementing our new servo made by Pierre. The problem is auto lock function doesn't work very well. Sometimes we can lock and sometimes we cannot. Also, we need to set the threshold of locking close to full reflection from IRMC cavity. In principle, the logic part will give 1 when our signal is smaller than the threshold we give. That means a threshold of half maximum should work well. However, not it doesn't work.

However, we found if we move high voltage driver and make the TEM00 peak close to the center of the ramp signal. The auto lock system can work very well. After this success of locking, we measured OLTF and moved Gain to have good phase margin and gain margin. At least, we know the locking problem doesn't come from filter design.