I forgot to report the calibration factors of the OMC QPD and DCPD. The data were taken on May 17th, 2022 @NAOJ Mitaka.
| Power[mW] | QPD1[V] | Calibration factor[mW/V] | QPD2[V] | Calibration factor[mW/V] |
| 70.03 | 6.29 | 11.1 | 6.40 | 10.9 |
| Power[mW] | DCPD1 [V] | Cal factor | DCPD2 [V] | Power [mW] |
| 16.5 | 1.16 | 14.2 | 1.16 | 14.2 |
Here, QPD1 is the one behind DCPDs, while QPD2 is the one on the corner of the breadboard
We estimate a theoretical value of the conversion factor.
Quantum efficiency ~ 0.7 [A/W] (EG&G/Perkin-Elmer/C30665)
Transimpedance = 100 or 400 [Ohm]
DC value of TF (Pod + DCPD driver) ~ 6 [dB] (from Dan Chen's report)
Then the conversion factor from input beam power [mW] to the output voltage from the DCPD driver [V] is:
The transimpedance in measurement in Mitaka was 100 Ohm, and there is a difference by a factor of two. This might be because the power was measured before the half BS (see OBS4 in the attached file. It comes from here). So the power distribution to watch PD is half of the value in the report, and the conversion factors should be half accordingly.
