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Entry  Fri Jun 25 10:47:08 2010, Aidan, Misc, aLIGO Modeling, Uploaded aLIGO axicon+ITM COMSOL model to the 40m SVN aLIGO_axicon_spacing_post-magnification_optimization.jpg
    Reply  Fri Jun 25 10:59:43 2010, Aidan, Misc, aLIGO Modeling, Uploaded aLIGO axicon+ITM COMSOL model to the 40m SVN Screen_shot_2010-06-25_at_11.01.38_AM.png
Message ID: 59     Entry time: Fri Jun 25 10:47:08 2010     Reply to this: 60
Author: Aidan 
Type: Misc 
Category: aLIGO Modeling 
Subject: Uploaded aLIGO axicon+ITM COMSOL model to the 40m SVN 

I added a COMSOL model of the aLIGO ITM being heated by an axicon-formed annulus to the 40m SVN. The model assumes a fixed input beam size into an axicon pair and then varies the distance between the axicons. The output is imaged onto the ITM with varying magnitudes. The thermal lens is determined in the ITM and added  to the self-heating thermal lens (assuming 1W absorption, I think - need to check). The power in the annulus is varied until the sum of the two thermal lenses scatters the least amount of power out of the TEM00 mode of the IFO.

https://nodus.ligo.caltech.edu:30889/svn/trunk/comsol/TCS/aLIGO/

The results across the parameter space (axicon separation and post-axicon-magnification) are attached. These were then mapped from this space to the space of annulus thickness vs annulus diameter, (see elog here).

 

 

Attachment 1: aLIGO_axicon_spacing_post-magnification_optimization.jpg  621 kB  Uploaded Fri Jun 25 11:52:44 2010  | Hide | Hide all
aLIGO_axicon_spacing_post-magnification_optimization.jpg
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