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Entry  Mon Jul 29 22:30:34 2013, tara, Notes, optic, coating optimization for AlGaAs multilayer1.JPGmultilayer2.JPGopt1_2013_07_29.pngnb_opt1_2013_07_29.pngT1200003_refcav.png
    Reply  Wed Jul 31 00:31:39 2013, tara, Notes, optic, coating optimization for AlGaAs 
       Reply  Fri Aug 9 17:58:01 2013, tara, Notes, optic, coating optimization for AlGaAs TOoptimized_2013_08_09.pngTOoptimized_2013_08_09.figTO_opt_200ppm_layer.pngTO_opt_200ppm_layer.fig2013_08_09_TOopt_200ppm.mat
          Reply  Tue Aug 27 16:11:26 2013, tara, Notes, optic, coating optimization for AlGaAs:error analysis 8x
             Reply  Wed Aug 28 21:21:38 2013, tara, Notes, optic, GWINC for TO calculation: recap 
             Reply  Sun Sep 1 18:38:37 2013, tara, Notes, optic, coating optimization for AlGaAs:error analysis 7x
                Reply  Mon Sep 2 18:31:46 2013, tara, Notes, optic, coating optimization for AlGaAs:error analysis 
                   Reply  Wed Sep 18 21:55:11 2013, tara, Notes, optic, coating optimization for AlGaAs:error analysis opt_coatings.mat
                      Reply  Thu Sep 19 20:38:17 2013, tara, Notes, optic, coating optimization for AlGaAs:error analysis power_vs_mirror_size.png
                Reply  Fri Sep 20 19:26:45 2013, tara, Notes, optic, coating optimization for AlGaAs:error analysis error_check_params.pngerror_check_params.figerror_thick_params_compare.pngerror_thick_params_compare.fig
                   Reply  Fri Sep 20 21:19:29 2013, Matt A., Notes, optic, coating optimization for AlGaAs:error analysis 
                   Reply  Sat Sep 21 23:49:29 2013, rana, Notes, optic, coating optimization for AlGaAs:error analysis 
                      Reply  Sun Sep 22 00:27:09 2013, some random goon, Notes, optic, coating optimization for AlGaAs:error analysis 
                         Reply  Mon Sep 23 18:07:22 2013, rana, Notes, optic, coating optimization for AlGaAs:error analysis 
                            Reply  Mon Sep 23 18:50:05 2013, tara, Notes, optic, coating optimization for AlGaAs:error analysis compare_indices.pngcompare_indices.figcompare_indices.png
                               Reply  Thu Sep 26 23:25:40 2013, tara, Notes, optic, coating optimization for AlGaAs:error analysis  8x
                                  Reply  Thu Oct 3 10:34:32 2013, tara, Notes, optic, coating optimization for AlGaAs:error analysis  
                                     Reply  Thu Oct 10 01:59:24 2013, tara, Notes, optic, coating optimization for AlGaAs:error analysis  
                                        Reply  Fri Oct 11 15:23:54 2013, tara, Notes, optic, coating optimization for AlGaAs:electric field in coating layer 6x
                                           Reply  Mon Oct 14 21:02:00 2013, tara, Notes, optic, coating optimization for AlGaAs:variation in x 
                                           Reply  Sun Oct 27 20:12:25 2013, tara, Notes, optic, photothermal noise in AlGaAs Int_cotings.pngInt_cotings.fig
                                              Reply  Wed Dec 18 21:05:28 2013, tara, Notes, optic, photothermal noise in AlGaAs: thickness resolution 8x
                                                 Reply  Sat May 17 22:01:28 2014, tara, Notes, optic, Coating TO opt for Adv LIGO: ETM 7x
                                                    Reply  Sun May 18 10:45:42 2014, tara, Notes, optic, Coating TO opt for Adv LIGO dOpt_ITM1.pngdOpt_ITM1.figAdvLIGO_AlGaAs.pngAdvLIGO_AlGaAs.fig
                                           Reply  Sat Jun 20 10:14:50 2015, Evan, Notes, optic, coating optimization for AlGaAs:electric field in coating layer Efieldtrans.pdf
Message ID: 1425     Entry time: Sat May 17 22:01:28 2014     In reply to: 1392     Reply to this: 1426
Author: tara 
Type: Notes 
Category: optic 
Subject: Coating TO opt for Adv LIGO: ETM 

Here is a prelim result for AlGaAs TO opt for ETM coating.

 

The optimization is named opt_ETM5 in .mat file. The structure is in optical length unit ( the physical thickness = (opt length) * 1064e-9 / n). The first layer is the air-coating GaAs layer . For the current optimization (opt_ETM5.mat) the transmission is 5.4 ppm, the reflected phase is off by about 2 degrees. 

dOpt_ETM5.png

opt_ETM5_nb.png

opt_ETM5_RT.png

ETM parameters used in the optimization

  • Spot radius (1/e^2 power) = 6 cm
  • Substrate radius =19 cm (GWINC)
  • Substrate thickness = 20 cm (GWINC)
  • Target transmission = 5 ppm

Note about optimization:

  •  The current optimization is just a prelim result for demonstrating that it is possible to optimize coating structure for ETM.
  • I have not included any uncertainties in the result.
  • The cost function used for this optimization is a only for nH = 3.48, nL = 2.977. So the coating properties might change rapidly with the uncertainties of the refractive indices see PSL:1356. I have not used the cost function with multi-value refractive indicesbecause this optimization is intended for parameter configuration (adjusting the target TO noise level, weight functions for each parameters, numbers of layer). 
  • The optimization was done for room temperature (300 K) @1064nm.
  • All the codes are attached in the zip file.

 To run the code:

  • run optETM.m with the current parameters. The result structure will be called xout in matlab workspace.
  • use CoatingThermalNoiseCalcETM.m to plot the noise budget.
  • I might miss some functions in the zip file, one is multidiel_rt.m , those are available on svn directory
Attachment 1: ETM_TO_OTP.zip  18 kB  Uploaded Sat May 17 23:21:08 2014
Attachment 2: opt_ETM_2014_05_17.mat  3 kB  Uploaded Sat May 17 23:21:43 2014
Attachment 6: dOpt_ETM5.fig  15 kB  Uploaded Sun May 18 00:28:47 2014
Attachment 7: opt_ETM5_nb.fig  73 kB  Uploaded Sun May 18 00:29:25 2014
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