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Entry  Thu Nov 5 02:18:32 2015, gautam, Update, LSC, FSR and linewidth measurements with phase tracker 
    Reply  Fri Nov 6 15:56:00 2015, gautam, Update, LSC, FSR and linewidth measurements with phase tracker Xcalib.pdfYcalib.pdfY_scan_log.pdf2015-11-05_phase_tracker_calib.dat.zip2015-11-04_y_arm_scan.dat.zip
       Reply  Mon Nov 9 11:34:51 2015, yutaro, Update, LSC, FSR and linewidth measurements with phase tracker plt.pngfitresult_and_code.zip
          Reply  Mon Nov 9 14:24:36 2015, yutaro, Update, LSC, FSR and linewidth measurements with phase tracker 
             Reply  Mon Nov 9 15:59:06 2015, ericq, Update, LSC, FSR and linewidth measurements with phase tracker 
                Reply  Mon Nov 9 16:58:59 2015, gautam, Update, LSC, FSR and linewidth measurements with phase tracker Y_scan.pdfmodDepth.pdfMatlab_code.zip
                   Reply  Tue Nov 10 02:34:28 2015, gautam, Update, LSC, Updated interpretation of peaks Y_scan.pdfmodDepth.pdf
                      Reply  Tue Nov 10 11:06:02 2015, yutaro, Update, LSC, Updated interpretation of peaks HOMlocation.pnghomfit.png
                         Reply  Tue Nov 10 11:40:03 2015, Koji, Update, LSC, Updated interpretation of peaks 
                            Reply  Tue Nov 10 16:34:00 2015, yutaro, Update, LSC, Updated interpretation of peaks homfit2.png
                               Reply  Fri Nov 13 17:33:39 2015, gautam, Update, LSC, g-factor measurements findGFactor.zip
                      Reply  Tue Nov 10 11:41:56 2015, Koji, Update, LSC, Updated interpretation of peaks 
       Reply  Fri Nov 13 15:48:16 2015, gautam, Update, LSC, Phase tracker calibration using Rubidium standard 6x
Message ID: 11740     Entry time: Mon Nov 9 11:34:51 2015     In reply to: 11738     Reply to this: 11741
Author: yutaro 
Type: Update 
Category: LSC 
Subject: FSR and linewidth measurements with phase tracker 

I fitted the data obtained with the FSR and linewidth measurements and I've got FSR and finesse of y-arm by fitting.

The fitted data and the fitting results are attached.

 

Summary:

FSR = 3.9704 MHz (ave. of two FSRs, 3.9727 MHz and 3.9681 MHz)

finesse = 401 +/- 11

estimated loss = 1812 (+456 / - 431) ppm

 

Detail:

I found peaks from the data and fitted each peak by Lorentzian, automatically with Python (the sourse code I used is attached).

3 parameters of Lorentzian for each peak and their fitting errors are attached.

Then, using 3 peaks of carrier resonance, I calculated FSR, finesse, and loss.

The error of finesse came from that of linewidth.

When calculating the loss, I used the value of 1.384 % for transmission of ITMY. 

 

Note:

Since the finesse is mostly determined by the transmission of ITM, the relative error of loss estimation is larger (about 25 % ) though the relative error of finesse is about 3 %. Therefor we have to find the reason why each estimated linewidth varies that largely, and measure finesse more accurately.

 

Attachment 1: plt.png  135 kB  | Hide | Hide all
plt.png
Attachment 2: fitresult_and_code.zip  4 kB
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