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Entry  Mon Jan 16 21:03:47 2017, rana, Summary, IOO, MCL / MCF / Calibration c1ioo_zoom_MCLF.pngMCL.pdf
    Reply  Wed Jan 18 12:34:21 2017, ericq, Summary, IOO, MCL / MCF / Calibration 
       Reply  Wed Jan 25 18:18:08 2017, Koji, Summary, IOO, MCL / MCF / Calibration 
    Reply  Fri Mar 24 12:21:27 2017, gautam, Summary, IOO, MCL / MCF / Calibration 6x
       Reply  Mon Mar 27 12:48:36 2017, rana, Summary, IOO, MCL / MCF / Calibration 
          Reply  Mon Mar 27 22:40:44 2017, Koji, Summary, IOO, MCL / MCF / Calibration 
Message ID: 12905     Entry time: Fri Mar 24 12:21:27 2017     In reply to: 12723     Reply to this: 12907
Author: gautam 
Type: Summary 
Category: IOO 
Subject: MCL / MCF / Calibration 

I repeated this measurement as follows:

  1. Added a filter in the MC_F filterbank (FM9) to account for the Pomona box between the PZT control signal and the laser PZT (pole@2.9Hz). So the filter bank at the time of TF measurement looks like this:
  2. Measured TF from driving MC2 (with C1:SUS-MC2_MCL_OUT channel) to C1:IOO-MC_F, which is the output of the above filter bank. The response is the expected 1/f^2 shape of the free optic
  3. From this transfer function, the magnitude is 0.0316 ct/ct. Using the value of 6nm/ct for the MC2 actuator gain that I found in a previous elog entry, I calibrated the MC_F output into Hz using the calibration factor 3.95MHz/ct (FM10 in the above filterbank).

Here is a calibrated MC_F spectrum:

RXA: I've added this plot of the free-running noise of the Lightwave NPRO which is probably similar to our Innolight Mephisto. Seems like the laser is quieter than MC_F everywhere below 100 Hz.

Attachment 2: MCF_cal.pdf  15 kB  | Hide | Hide all
Attachment 3: MCFTF_mag.pdf  6 kB  Uploaded Fri Mar 24 13:36:14 2017  | Hide | Hide all
Attachment 4: MCFTF_phase.pdf  3 kB  Uploaded Fri Mar 24 13:36:20 2017  | Hide | Hide all
Attachment 5: MCFTF_coh.pdf  3 kB  Uploaded Fri Mar 24 13:36:28 2017  | Hide | Hide all
Attachment 6: FreqNoiseReq.pdf  19 kB  Uploaded Fri Mar 24 14:01:36 2017  | Hide | Hide all
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