Aritomi and Yuhang

After seeing the effect of rubber in entry 1508, we tried to put it at another position. Considering what we reported in entry 1471, we found the resonance of 500Hz/600Hz is due to different base plate we put for phase shifter. So it seems to be an overall resonance of the mirror mount.(flag pole mode) So we decided to put a piece of rubber under the whole mirror mount. We thought it will damp the resonance of 500Hz/600Hz. The rubber and the position we put for CC1 and CC2 is shown in the attached figure 1 and 2.

After put them we increase gain little by little, we couldn't find the resonance of 500Hz/600Hz. It makes a big difference. The measurement of the optomechanical transfer function is attached.