Aritomi and Yuhang

We found that the incident beam into the filter cavity actually it is not jittering.

But we confirm that ITM and ETM are jitter. For ITM, it is obvious that reflection is jittering.  For ETM, we found ETM reflection and it was moving.

Please check the attached video. This is the green incident beam on the second target. https://drive.google.com/open?id=1O6HZabKGtyzbuyYSPC_QGHkkhuE3W1YI