Today I did OMC scans, leaving the sidebands on, so that we can try to use the sidebands to calibrate the PZT voltage into frequency and estimate finesse from the scan.
I left the input power at 2W (1.8W on PRM), and did the scan slowly to try to avoid the saturations that Keita observed in 72254. I also took scans at three different speeds.
I took scans with the OMC ASC on the QPDs. We know that there is a slightly better alignment for single bounce, but don't think that this should matter much for the finesse measurement that we get this way.
Times:
- 14/11/2023 19:05:00 UTC (200 seconds ramp up, then 200 seconds down) (red)
- 14/11/2023 18:53:01 UTC (100 seconds ramp up, then 100 seconds down) (mint green)
- 14/11/2023 18:48:03 UTC (50 seconds up, 50 seconds down, twice) This scan seems to have rather different peak heights, so I think the scan was too fast and we shouldn't use this data. (blue)
- 14/11/2023 18:57:49 super slow scan, accidentally put an extra 0 in the frequency of the excitation. This data may not be very useful because the laser frequency could be drifting over time with this very slow scan. (brown)