R&D (FilterCavity)
NaokiAritomi - 18:20, Saturday 29 February 2020 (2059)
Shot noise and squeezing with additional faraday

[Aritomi, Yuhang, Eleonora]

We measured shot noise and squeezing with additional faraday before homodyne to reduce back scattering (attached picture). 

Difference between black and blue is back scattering with faraday which is much smaller than before. Difference between  blue and red curve might be effect of CC. 

Images attached to this report
2059_20200229102102_sqz20200229.png
Comments related to this report
EleonoraCapocasa - 12:00, Tuesday 03 March 2020 (2061)

Note that back scattering on Saturday was particulary bad. It seemed the mirrors were more excited than usual.

By the way I remember that before Christmas, whitout the additional Faraday, we managed to measure less then 2 dB above shot noise at 30 Hz. See here