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Entry  Sun Jan 24 18:35:47 2010, Frank, Laser, RefCav, new slow actuator values 
    Reply  Tue Jan 26 03:38:10 2010, rana, Laser, RefCav, frequency findings  
       Reply  Wed Jan 27 11:25:33 2010, Frank, Laser, RefCav, frequency findings  
          Reply  Wed Feb 3 16:19:52 2010, Tara Chalermsongsak, Laser, RefCav, frequency findings  power_at_AOM.jpgReflected_pwr_from_AOM.jpg
             Reply  Wed Feb 3 18:58:50 2010, Tara, Laser, RefCav, frequency findings  comparison.JPGTbeam.JPGRbeam.JPG
Message ID: 46     Entry time: Wed Feb 3 18:58:50 2010     In reply to: 45
Author: Tara 
Type: Laser 
Category: RefCav 
Subject: frequency findings  

When the VCO is modulated by a triangular function +/- 6V, a small fluctuation is observed in transmitted and reflected beam. There might be some small constant phase shift between the two.

at 78 MHz  the modulation width is about 0.3 MHz, with +/- 2.4% amplitude

 at   79.5 MHz,  the width is 0.238 MHz, +/- 1.1 % in amplitude,

  at 81 MHz, the width is 0.193 MHz, +/- 1.5% in amplitude.

The first plot shows the comparison between the transmitted beam and the reflected beam between 78 - 82 MHz. The second and the third plots are the whole data from the transmitted beam and the reflected beam respectilvely. The data is taken aroud 2010-02-03 20:00:00 UTC.

Attachment 1: comparison.JPG  300 kB  | Show | Hide all | Show all
Attachment 2: Tbeam.JPG  221 kB  | Show | Hide all | Show all
Attachment 3: Rbeam.JPG  249 kB  | Hide | Hide all | Show all
Rbeam.JPG
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