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Entry  Thu Mar 4 17:04:52 2021, Paco, General, Design specs, Silicon TM dichroic coatings for phase I ETM_coating_candidates.pdfITM_coating_candidates.pdf
    Reply  Wed Mar 17 19:51:42 2021, Paco, General, Design specs, Silicon TM dichroic coatings for phase I ETM_R_210317_1927.pdfETM_Layers_210317_1927.pdfETM_nominal_cornerPlt.pdf
       Reply  Wed Mar 17 21:24:27 2021, gautam, General, Design specs, Silicon TM dichroic coatings for phase I 
          Reply  Wed Mar 24 17:36:46 2021, Paco, General, Design specs, Least common multiple stacks and varL cost ETM_Layers_210323_0925.pdf
             Reply  Fri Apr 2 19:59:53 2021, Paco, General, Design specs, Differential evolution strategies diffevostrategies.pdf
                Reply  Fri Jun 4 11:09:27 2021, Paco, General, Design specs, HR coating tolerance analysis 
          Reply  Wed Mar 24 17:42:50 2021, Paco, General, Design specs, Silicon TM dichroic coatings for phase I 
Message ID: 4     Entry time: Thu Mar 4 17:04:52 2021     Reply to this: 6
Author: Paco 
Type: General 
Category: Design specs 
Subject: Silicon TM dichroic coatings for phase I 

Have been using the 40m Coatings repo code by Gautam (with some modifications to make dichroic designs under Ta2O5_Voyager), as well as the parameters compiled in the Mariner wiki for Silica-tantala thin films. Here are some of the top picks.

ETM

For ETM, the target transmissivities are 5.0 ppm @ 2128.2 nm and 50.0 ppm @ 1418.8 nm. After different combinations of differential evolution walkers, numbers of layers, thickness bounds, a couple of different optimization strategies, the optimum design has consistently converged with 19 - 26 layer pairs (total of 38 - 52 layers). The picks are based on the sensitivities, E_field at the boundary, and a qualitatively uniform stack (discarded "insane-looking" solutions). The top picks in Attachment 1 may be a good starting point for a manufacturer. In order of appearance, they are:

  1. ETM_210218_1632
  2. ETM_210222_1621
  3. ETM_210302_1210
  4. ETM_210302_1454

ITM

For ITM, the target transmissivities are 2000 ppm @ 2128.2 nm and 50.0 ppm @ 1418.8 nm (critically coupled cavity for AUX). The lower trans for 2128.2 nm made this easier faster to converge, although the number of thin film layers was equally centered about ~ 50 layers. Haven't explored as much in the parameter space, but the top picks in Attachment 2 are decent for approaching manufacturer. In order of appearance, they are:

  1. ITM_210303_1806
  2. ITM_210204_1547
  3. ITM_210304_1714
Attachment 1: ETM_coating_candidates.pdf  200 kB  | Hide | Hide all
ETM_coating_candidates.pdf ETM_coating_candidates.pdf ETM_coating_candidates.pdf ETM_coating_candidates.pdf ETM_coating_candidates.pdf ETM_coating_candidates.pdf ETM_coating_candidates.pdf ETM_coating_candidates.pdf
Attachment 2: ITM_coating_candidates.pdf  152 kB  | Hide | Hide all
ITM_coating_candidates.pdf ITM_coating_candidates.pdf ITM_coating_candidates.pdf ITM_coating_candidates.pdf ITM_coating_candidates.pdf ITM_coating_candidates.pdf
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