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Entry  Thu Apr 9 23:11:27 2009, rob, Summary, Locking, Laser PM to PO-DC transfer functions at multiple CARM offsets CARMoffs1.pngCARMoffs2.pngCARMcarpet.png
    Reply  Thu Apr 9 23:20:35 2009, rob, Summary, Locking, Laser PM to REFL-DC transfer functions at multiple CARM offsets CARMoffs1_r.pngCARMoffs2_r.pngCARMcarpet_r.png
       Reply  Fri Apr 10 03:10:08 2009, rana, Summary, Locking, Laser PM to REFL-DC transfer functions at multiple CARM offsets 
Message ID: 1465     Entry time: Thu Apr 9 23:11:27 2009     Reply to this: 1466
Author: rob 
Type: Summary 
Category: Locking 
Subject: Laser PM to PO-DC transfer functions at multiple CARM offsets 

I've plotted some transfer functions showing the response at POB DC to laser frequency (phase) noise.  There are transfer functions for multiple CARM offsets.  Basically, the transfer function looks like the DARM transfer function when the CARM is at zero offset, and is super-wonky elsewhere.  POB-DC is not a good CARM signal for intermediate stages of lock acquisition in a dual-recycled interferometer.  We should look into switching back to REFL-DC.

 

Attachment 1: CARMoffs1.png  71 kB  Uploaded Fri Apr 10 12:24:11 2009  | Hide | Hide all
CARMoffs1.png
Attachment 2: CARMoffs2.png  64 kB  Uploaded Fri Apr 10 12:25:05 2009  | Hide | Hide all
CARMoffs2.png
Attachment 3: CARMcarpet.png  28 kB  Uploaded Fri Apr 10 12:25:24 2009  | Hide | Hide all
CARMcarpet.png
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