R&D (FilterCavity)
AkihiroTomura - 01:21, Saturday 24 February 2018 (674)
Noise spectra of green/IR beam

Here is attached noise spectra of the filter cavity transmission and reflection. As for transmission spectra, data measured in two different frequency span were put together afterwards to retain good resolution in lower frequency range. There are spikes on IR transmission in the range above 10kHz which do not exist in reflection nor in green. We also examined IR beam before entering the cavity and confirmed that there were not such spikes (data not shown here).

Images attached to this report
674_20180223170658_20180221psd.png
Comments related to this report
EleonoraCapocasa - 10:05, Tuesday 27 February 2018 (681)

We have verified that the spikes oberved in the IR transmission,  in the region above 10 kHz are prensent even if there is no light impingin on the photodiode. They are likely be due to electronics.