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Entry  Tue Nov 29 14:22:03 2011, Zach, Update, RF System, EOM temp stabilization performance Screen_shot_2011-11-29_at_1.33.50_PM.pngScreen_shot_2011-11-29_at_1.34.06_PM.pngScreen_shot_2011-11-29_at_1.41.03_PM.png
    Reply  Tue Nov 29 15:25:29 2011, steve, Update, RF System, EOM temp stabilization performance 2days.png
       Reply  Tue Nov 29 18:17:27 2011, Zach, Update, RF System, EOM temp stabilization performance 
    Reply  Tue Nov 29 22:10:18 2011, kiwamu, Update, RF System, RFAM fluctuation reduced RFAM_withEOMheater_edit.png
       Reply  Tue Nov 29 23:03:34 2011, Zach, Update, RF System, RFAM fluctuation reduced 
          Reply  Wed Nov 30 03:01:55 2011, kiwamu, Update, RF System, RFAM fluctuation reduced 
Message ID: 6040     Entry time: Tue Nov 29 18:17:27 2011     In reply to: 6036
Author: Zach 
Type: Update 
Category: RF System 
Subject: EOM temp stabilization performance 

Quote:

 It is not obvious what is working.

 

It should be. As I mentioned, you can only trust the Stochmon signals between 0840 and 1130 UTC; before this time, the temperature controller was not connected, and after this time, c1sus is shut down and the MC is not locked, as you can see in your DV plot.

Within this time frame, the Stochmon signals are relatively stabilized (though there is some residual common-mode-ish drift since we are not using RFAM as the error signal---i.e., other things like laser power and frequency can mix in). Also, anytime after 0840, the controller signals behave as they should (these are unaffected by the status of c1sus):

  • The EOM temperature signal (error signal) is stabilized to a value very near zero
  • The heater drive signal (control signal) moves around in such a way as to null the error signal, and you can confirm that it looks roughly like the opposite of the FSS_RMTEMP signal, as it should.

I am concerned with the other issues that I mentioned in my previous post, namely:

  1. Error signal dominated by digitization noise above some low frequency despite 100x amplification
  2. Strange ~0.01-Hz level disturbances in error signal.
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