YuhangZhao - 00:15, Monday 07 September 2020 (2206)
Filter cavity end mirror driving balance issue
Aritomi and Yuhang
As reported in elog2173, the driving for end mirror has some coupling between pitch and yaw. To decouple them, we decide to modify the driving matrix.
However, we found out that the coupling between pitch and yaw is different for different excitation strength. The coupling situation is shown in the attached figures and sumarized in the following table.
| excitation | coupling (pitch to yaw) |
| 5000 | 22.5% |
| 1000 | 3.4% |
This measurement is done after optimizing the coupling with excitation of 1000. The pitch driving matrix is as following:
| H1 | H2 | H3 | H4 |
| -0.052 | 1.4 | 0.052 | 1 |
Images attached to this report
