[Aritomi, Yuhang]
Current mode matching is as follows. Mode matching is around 90%. TEM00 is fluctuating a lot due to alignment drift of suspended mirrors and it's difficult to improve the alignment without auto alignment.
| Mode | AOM frequency (MHz) | IR transmission |
| TEM00 | 109.03593 | 2400 |
| HG10 | 109.43126 | 180 |
| HG01 | 109.43207 | 250 |
| IG02 | 109.82923 | 115 |
| offset | 94 |
Then we checked IR reflection and it was cutted. We measured BAB reflection from filter cavity when BAB is on/off resonance.
Reflectivity when BAB is on/off resonance is 44% and 77%. "real" cavity reflectivity which is ratio of these reflectivity is 57% and this is too low compared with ~80% in paper we published last year.