YuhangZhao - 13:56, Thursday 10 October 2019 (1729)
Measurement of IR power loss from two PBS before and after the in-vacuum FI
We have two reference points for IR injection to filter cavity(FC). They are from the two PBS before and after the in-vacuum FI. And this will be also a loss for squeezing in the future. Also, if we want to monitor the power we are injecting to FC, this can be a choice of checking point.
So we measured the power arriving at these two points.
| power loss from PBS before in-vacuum FI (first PBS) | 0.59uW | attached photo 1 | so the polarization before PR chamber is optimized better |
| power loss from PBS after in-vacuum FI (second PBS) | 2.78uW | attached photo 2 | so the polarization before the second PBS is not optimized very well |
We could optimize the HWF after the in-vacuum rotator, but we will lose some isolation factor.
Actually, Matteo said maybe we can have the choice to optimize the Faraday rotator, if so, our maximization of IR reflection should be done by optimizing the Faraday rotator.
Images attached to this report
