40m QIL Cryo_Lab CTN SUS_Lab TCS_Lab OMC_Lab CRIME_Lab FEA ENG_Labs OptContFac Mariner WBEEShop
  PSL  Not logged in ELOG logo
Message ID: 1018     Entry time: Wed Jul 11 18:10:48 2012
Author: Sarah 
Type: DailyProgress 
Category: NoiseBudget 
Subject: Coating Brownian Noise 

I used Numata et al's results to calculate the Coating Brownian Noise and compared this to what we measure currently.

Using the parameters for our setup and the equation for the Coating Brownian Noise from Numata et al's : Wide-band direct measurement of thermal fluctuations in an interferometer , I calculated the Coating Brownian Noise (I attached my code for the calculation). I then calculated the total noise with the Coating Noise using Numata's result, instead of our current calculated result. The following noise budget shows the results:

numata_nb.png 

 The black curve shows the total noise as calculated with the coating noise from Numata's results. Comparing this to the current beat measurement, the pink curve, there are clear similarities in the shape, with the total noise using Numata's coating noise results lying slightly beneath our current total nosie. The green curve shows the Coating Brownian Noise using Numata's results, and the yellow line is the ci plot for our current calculation for Coating Brownian Noise. As it turns out, our current estimate for the Coating Brownian Noise is about 30% smaller than the estimate using the results of Numata's work. 

Attachment 1: numata_noise.m.zip  1000 Bytes
Attachment 3: numata_nb.fig  300 kB  Uploaded Mon Jul 16 21:49:48 2012
ELOG V3.1.3-