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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: 7     Entry time: Wed Mar 17 21:24:27 2021     In reply to: 6     Reply to this: 8   9
Author: gautam 
Type: General 
Category: Design specs 
Subject: Silicon TM dichroic coatings for phase I 

I guess you have tried it already - but does enforcing the stacks to be repeating bilayer pairs of the same thickness fail miserably? When doing this for the PR3 optic @1064nm, I found that the performance of a coating in which the layers are repeating bilayers (so only 2 thicknesses + the cap and end are allowed to vary) was not that much worse than the one in which all 38 thicknesses were allowed to vary arbitrarily. Although you are aiming for T=50ppm at the second wavelength (which isn't the harmonic) which is different from the PR3 reqs. This kind of repetitive structure with fewer arbitrary thicknesses may be easier to manufacture (and the optimizer may also converge faster since the dimensionality of the space to be searched is smaller). 

Cool starfish 🌟 . What is the interpretation of the area enclosed by the vertices? Is that the (reciprocal) cost? So the better solution maximizes the area enclosed?

Quote:

Attachment 2 shows the stack. Surprisingly not as crazy (or maybe I have internalized the old "crazy" as "normal")

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