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Entry  Thu Sep 12 18:12:26 2013, Matt A., Summary, NoiseBudget, Coating Thermal Noise Calculator 6x
    Reply  Fri Sep 13 13:40:43 2013, rana, Summary, NoiseBudget, Coating Thermal Noise Calculator MattThermal.pdf
    Reply  Tue Sep 17 19:43:45 2013, tara, Summary, NoiseBudget, Coating Thermal Noise Calculator 
       Reply  Thu Sep 19 14:55:11 2013, tara, Summary, NoiseBudget, Coating Thermal Noise Calculator ThermalUpdateEmbed.pdfThermalUpdateEmbed2.pdf
          Reply  Thu Sep 19 18:09:18 2013, tara, Summary, NoiseBudget, Coating Thermal Noise Calculator 
Message ID: 1343     Entry time: Thu Sep 19 18:09:18 2013     In reply to: 1342
Author: tara 
Type: Summary 
Category: NoiseBudget 
Subject: Coating Thermal Noise Calculator 

Quote:

 

Tara noticed an accidental re-definition in my old code. I fixed it, and updated the svn. This fixes most of the discrepancies, but shifts the difference in thermo-optic to the low-frequency region.

Attachment 1 is the comparison from case 3 between mine and Tara's calculations of his optimized coating structure.

Attachment 2 is the comparison from case 2 between mine and Tara's calculations of a 55-layer 1/4-wavelength stack.

 I discussed the calculation with Matt. The error in TO noise is large because it is a fraction of something small. Mostly it comes from TE part. The error in TO noise appears large (10%-20%) because the TO level is small.  Otherwise, the rests are in good agreement, and I think we should be able to order soon. 

 Below, summary of the calculation, dTE is alpha_effective * coating thickness, dTO is beta effective * lambda. 0.2% difference in dTE and 0% difference in dTR can cause error upto 40% in dTO when dTE and dTR cancel each other really well. But this will be insignificant, since the final TO levels are still in the same magnitude.

  Matt Gwinc
dTE 8.161e-11 8.141e-11
dTR -8.11e-11 -8.11e-11
dTO (dTE+dTR) 4.87e-13 2.88e-13

 

The summary of the TO cancellation is in wiki page AlGaAs

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