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Entry  Mon May 2 17:11:55 2016, rana, Update, COC, RC folding mirrors 
    Reply  Wed May 18 01:10:22 2016, gautam, Update, COC, Finesse modelling arms.pdfPRC.pdfSRC.pdfFinesse_model.zip
       Reply  Tue May 24 22:49:02 2016, gautam, Update, COC, Finesse modelling - mode overlap scans 9x
          Reply  Tue May 24 23:17:37 2016, ericq, Update, COC, Finesse modelling - mode overlap scans 
             Reply  Thu Jun 16 15:57:46 2016, gautam, Update, COC, Contrast as a function of RoC of ETMX contrastDefect.pdffinesseCode.zip
                Reply  Thu Jun 16 18:42:12 2016, rana, Update, COC, Contrast as a function of RoC of ETMX 
                   Reply  Thu Jun 16 23:02:57 2016, gautam, Update, COC, Contrast as a function of RoC of ETMX contrastDefect.pdf
                      Reply  Mon Jun 20 01:38:04 2016, rana, Update, COC, Contrast as a function of RoC of ETMX 
                         Reply  Mon Jun 20 18:07:15 2016, gautam, Update, COC, Contrast as a function of RoC of ETMX contrastDefectComparison.pdf
             Reply  Tue Jun 28 16:06:09 2016, gautam, Update, COC, RC folding mirrors - further checks C1_HOMcurves_Y.pdfC1_HOMcurves_DR.pdf
                Reply  Thu Jun 30 16:21:32 2016, gautam, Update, COC, Sideband HOMs resonating in arms image.jpegC1_HOMcurves_Y.pdfC1_HOMcurves_X.pdf
                Reply  Sat Aug 13 18:25:22 2016, gautam, Update, COC, RC folding mirrors - Numerical review PRX_consolidated.pdfSRX_consolidated.pdfGouy_PRC.pdfGouy_SRC.pdf
                   Reply  Tue Aug 16 11:51:43 2016, gautam, Update, COC, RC folding mirrors - Numerical review PRC_consolidated.pdfSRC_consolidated.pdfGouyPRC.pdfGouySRC.pdf
                      Reply  Tue Aug 16 16:38:00 2016, gautam, Update, COC, RC folding mirrors - Numerical review PRC_consolidated.pdfSRC_consolidated.pdfGouyPRC.pdfGouySRC.pdf
                         Reply  Wed Aug 17 14:37:36 2016, gautam, Update, COC, RC folding mirrors - Numerical review PRG.pdf
                            Reply  Wed Aug 17 16:28:46 2016, Koji, Update, COC, RC folding mirrors - Numerical review 
                            Reply  Mon Nov 21 15:34:24 2016, gautam, Update, COC, RC folding mirrors - updated specs Recycling_Mirrors_Specs_Nov2016.pdf
                               Reply  Thu Feb 23 10:59:53 2017, gautam, Update, COC, RC folding mirrors - coating optimization PR3_R_170222_2006.pdfPR3_123_TOnoise_170222_2203.pdfPR3_123_Layers_170222_2203.pdfPR3AR_R_170222_2258.pdfPR3AR_123_Layers_170222_2258.pdf
                                  Reply  Tue Mar 14 10:56:33 2017, gautam, Update, COC, RC folding mirrors - coating optimization PR3_R_170313_1701.pdfPR3AR_123_Layers_170313_1701.pdfPR3AR_R_170313_1752.pdfPR3AR_123_Layers_170313_1752.pdf
                                     Reply  Mon Apr 10 15:37:11 2017, gautam, Update, COC, RC folding mirrors - v3 of specs uploaded  8x
Message ID: 12847     Entry time: Thu Feb 23 10:59:53 2017     In reply to: 12631     Reply to this: 12887
Author: gautam 
Type: Update 
Category: COC 
Subject: RC folding mirrors - coating optimization 

I've now made a DCC page for the mirror specifications, all revisions should be reflected there.

Over the last couple of days, I've been playing around with Rana's coating optimization code to come up with a coating design that will work for us. The basic idea is a to use MATLAB's particle swarm constrained optimization tool to minimize an error function that is a composite of four penalties:

  1. Thermal noise - we use the proxy function from E0900068-v3 to do this
  2. Deviation from target T @1064nm, p-pol
  3. Deviation from target T @532nm, p and s-pol
  4. HR Surface field

On the AR side, I only considered 2 and 3. The weighting of these four components were set somewhat arbitrarily, but I seem to be able to get reasonable results so I am going with this for now. 

From my first pass at it, the numbers I've been able to get, for 19 layer pairs, are (along with some plots):

HR Side:

  • T = 50ppm, 1064nm p-pol
  • T = 99%, 532nm s and p-pol

       (in this picture, the substrate is to the right of layer 38)

AR Side:

  • R ~50ppm for 532nm, s and p-pol

   (substrate to the right of layer 38)

These numbers are already matching the specs we have on the DCC page currently. I am not sure how much better we can get the specs on the HR side keeping with 19 layer pairs... 

All of this data, plus the code used to generate them, is on the gitlab coatings page...

 

Attachment 1: PR3_R_170222_2006.pdf  96 kB  | Hide | Hide all | Show all
PR3_R_170222_2006.pdf
Attachment 2: PR3_123_TOnoise_170222_2203.pdf  43 kB  | Show | Hide all | Show all
Attachment 3: PR3_123_Layers_170222_2203.pdf  30 kB  | Hide | Hide all | Show all
PR3_123_Layers_170222_2203.pdf
Attachment 4: PR3AR_R_170222_2258.pdf  99 kB  | Hide | Hide all | Show all
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PR3AR_123_Layers_170222_2258.pdf
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