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Entry  Tue Jun 28 18:19:09 2022, Tomislav, Update, Electronics, Electronics noise electronics_noise_spectra.pngerror_signal.png
    Reply  Wed Jun 29 18:53:38 2022, rana, Update, Electronics, Electronics noise 
Message ID: 16958     Entry time: Tue Jun 28 18:19:09 2022     Reply to this: 16963
Author: Tomislav 
Type: Update 
Category: Electronics 
Subject: Electronics noise 

I measured electronics noise of WFSs and QPD (of the WFS/QPD, whitening, ADC...) by closing PSL and measuring the error signal. It was needed to put the offset in C1:IOO-MC_TRANS_SUMFILT_OFFSET to 14000 cts (without offset the sum of quadrants would give zero, and 14000 cts is the value when the cavity is locked). For WFS that are RF, if there is intensity noise at low frequencies, it is not affecting the measurement.

In the attachment please find the power spectrum of the error signal when the PSL shutter is on and off.

Attachment 1: electronics_noise_spectra.png  59 kB  Uploaded Tue Jun 28 19:30:20 2022  | Hide | Hide all
Attachment 2: error_signal.png  33 kB  Uploaded Tue Jun 28 19:30:23 2022  | Hide | Hide all
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