NaokiAritomi - 17:48, Sunday 06 October 2019 (1701)
IR alignment with dithering
[Aritomi, Yuhang]
We measured mode matching when filter cavity is aligned with pitch dithering. The result is as follows. Mode matching was around 90%. We found that when pitch dithering was engaged, pitch misalignment became less, but yaw misalignment became more.
| Mode | AOM frequency (MHz) | IR transmission |
| TEM00 | 109.03607 | 3000 |
| HG10 | 109.43128 | 350 |
| HG01 | 109.43219 | 200 |
| IG02 | 109.8288 | 115 |
| offset | 94 |
IR TEM00 transmission was fluctuating even when dithering was engaged (attached movie). Time scale of the movie is 2s and DC offset is 94.
We measured BAB reflection when BAB is on/off resonance. Off resonance reflectivity is 82% and the reflection might be still cutted.
Injection: 334uW
Reflection: 273uW (off resonance)
Reflection: 190-250uW (on resonance)
However, after one hour, IR was misaligned even though green was aligned well with dithering. We guess that it is because green and IR is not overlapping well.
Non-image files attached to this report
