Reports until 13:38, Monday 11 July 2016
H1 ISC (ISC)
haocun.yu@LIGO.ORG - posted 13:38, Monday 11 July 2016 (28324)
POP Beamsplitter Added

Sheila, Haocun

 

Due to the satuation of the photodetectors, we added a 90:10 beamsplitter (CVI BS1-1064-90-1025-45P) in the POP beam path.

WIth the input power of 2W (1.97W) in the interferometer:

Power before adding the BS:   POPX: 5.74mW       POP Air A: 2.56mW      POP Air B: 2.52mW     (total: 10.82mW)

Power after adding the BS:      POPX: 0.852mW     POP Air A: 0.4mW        POP Air B: 0.4mW       (total: 1.652mW)

Power right before the BS: 10.88mW; Power right after the BS: 1.82mW.

Both of the results gave us the transmission of the BS to be ~16%.
 
 
We also changed the whitening gain:
 
POP Air B: 
RF18: 18dB --> 36dB
RF90:
before: whitening gain: 21dB, digital filter: -21dB
after:  whitening gain: 18dB, no digital filter
 
POP Air A: 
RF9: 6dB --> 21dB
RF45: 6dB --> 21dB