H1 SQZ (SQZ)

nutsinee.kijbunchoo@LIGO.ORG - posted 22:54, Wednesday 28 November 2018 - last comment - 08:35, Thursday 29 November 2018(45567)

Post-vent squeezing

Sheila, Haocun, Daniel, Terry, Nutsinee

~5dB squeezing, ~8.5 dB anti-squeezing, NLG ~7

Green power was drifting slowly when we were taking the measurement so could be better. OPO locking crapped out just after we took the data so we didn't have more tonight. Haocun is working on the loss estimate. More recovery alog to follow.

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lisa.barsotti@LIGO.ORG - 07:31, Thursday 29 November 2018 (45569)

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Nice recovery, congratulations on your 5 dBs!

Let's wait for Haocun's analysis, but a quick check suggests that the sqz/anti-sqz numbers are not consistent with the NLG of 7. Getting 8.5dB of anti-sqz with NLG=7 requires huge loss, which would make impossible to achieve 5 dB of sqz.

nutsinee.kijbunchoo@LIGO.ORG - 08:35, Thursday 29 November 2018 (45572)

Link

I agree. Sadly we measured anti squeezing first when the input power to the coupler was ~18-19mW. By the time we get to measuring the squeezing the power dropped by at least a mW. More data is needed.