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Entry  Fri Sep 21 09:59:09 2018, yuki, Configuration, ASC, Y end table upgrade plan Pic_CurrentSetup_AUXYgreen.jpegModeMatchingSolution_Current.pdfModeMatchingSolution_Current_Magnified.pdfModeMatchingSolution_Optimized.pdfModeMatchingSolution_Optimized_Magnified.pdf
    Reply  Sun Sep 23 19:32:23 2018, yuki, Configuration, ASC, Y end table upgrade plan Pic_NewSetup0923_AUXYgreen.jpegModeMatchingSolution_Result.pdfModeMatchingSolution_Magnified_0923.jpgpic0923_1.jpgpic0923_2.jpg
       Reply  Mon Sep 24 11:09:05 2018, yuki, Configuration, ASC, Y end table upgrade plan pic0924_1.jpg
       Reply  Tue Sep 25 18:08:50 2018, yuki, Configuration, ASC, Y end table upgrade plan 
          Reply  Thu Sep 27 14:02:55 2018, yuki, Configuration, ASC, PZT driver board verification PZTdriverSimulationDiagram.pdfPZTdriverSimulationResult.pdfPZTdriverPerformanceCheck_ResultOUT.pdfPZTdriverPerformanceCheck_ResultMON.pdfPZTdriver.asc
             Reply  Sun Sep 30 20:14:51 2018, yuki, Configuration, ASC, QPD calibration QPDcalibrationXaxis.pdfQPDcalibrationYaxis.pdf
                Reply  Mon Oct 1 12:03:41 2018, not yuki, Configuration, ASC, PZT driver board verification 
                   Reply  Mon Oct 1 13:33:55 2018, yuki, Configuration, ASC, QPD calibration Pic_QPDcalibration.jpg
                      Reply  Tue Oct 2 18:50:53 2018, yuki, Configuration, ASC, PZT mirror calibration PZTM1calibrationCH2.pdfPZTM1calibrationCH1.pdfPZTM2calibrationCH2.pdfPZTM2calibrationCH1.pdf
                         Reply  Wed Oct 3 18:15:34 2018, yuki, Configuration, ASC, AI board improvement TF_AIboard.pdf
                            Reply  Thu Oct 4 00:44:50 2018, yuki, Configuration, ASC, AI board improvement 
                               Reply  Thu Oct 4 22:15:30 2018, yuki, Configuration, ASC, Y-end table upgrade AUXYGreenLock20180921.jpgPic_FormerSetup.jpegPic_CurrentSetup1004.jpg
                                  Reply  Fri Oct 5 00:46:17 2018, Koji, Configuration, ASC, Y-end table upgrade 
                                     Reply  Fri Oct 5 17:32:38 2018, yuki, Configuration, ASC, Y-end table upgrade 
                                        Reply  Mon Oct 8 00:46:35 2018, yuki, Configuration, ASC, Y-end table upgrade 
                                  Reply  Fri Oct 5 17:47:55 2018, gautam, Configuration, ASC, Y-end table upgrade 
                                     Reply  Fri Oct 5 22:49:22 2018, yuki, Configuration, ASC, Y-end table upgrade 
                                        Reply  Sun Oct 7 16:51:03 2018, gautam, Configuration, LSC, Yarm triggering changed 
                                           Reply  Sun Oct 7 22:30:42 2018, yuki, Configuration, LSC, Yarm Green locking was recovered Pic_NewLayout1007.jpgYendGreenModeMatching.zip
                                              Reply  Tue Oct 9 23:03:43 2018, yuki, Configuration, LSC, Yarm Green locking was recovered Pic_1Y4.jpgPic_PZTcable.jpg
                                                 Reply  Wed Oct 10 12:38:27 2018, yuki, Configuration, LSC, All hardware was installed 
          Reply  Mon Oct 1 20:39:09 2018, gautam, Configuration, ASC, c1asy 
             Reply  Mon Oct 8 18:56:52 2018, gautam, Configuration, ASC, c1asx filter coefficient file missing 
             Reply  Tue Oct 9 16:05:29 2018, gautam, Configuration, ASC, c1tst deleted, c1asy deployed. CDSoverview_ASY.png
    Reply  Wed Oct 3 14:24:40 2018, yuki, Configuration, ASC, Y end table upgrade plan 
       Reply  Mon Oct 15 20:11:56 2018, yuki, Configuration, ASC, Y end table upgrade plan 
          Reply  Wed Oct 17 20:46:24 2018, yuki, Configuration, ASC, Y end table upgrade plan 
Message ID: 14219     Entry time: Sun Sep 30 20:14:51 2018     In reply to: 14218     Reply to this: 14220
Author: yuki 
Type: Configuration 
Category: ASC 
Subject: QPD calibration 

[ Yuki, Gautam, Steve ]

Results:
I calibrated a QPD (D1600079, V1009) and made sure it performes well. The calibration constants are as follows:

X-Axis: 584 mV/mm
Y-Axis: 588 mV/mm

Details:
The calibration of QPD is needed to calibrate steeing PZT mirrors. It was measured by moving QPD on a translation stage. The QPD was connected to its amplifier (D1700110-v1) and +-18V was supplied from DC power supplier. The amplifier has three output ports; Pitch, Yaw, and Sum. I did the calibration as follows:

  • Center beam spot on QPD using steering mirror, which was confirmed by monitored Pitch and Yaw signals that were around zero.  
  • Kept Y-axis micrometer fixed, moved X-axis micrometer and measured the outputs. 
  • Repeated the procedure for the Y-axis. 

The results are attached. The main signal was fitted with error function and I drawed a slope at zero crossing point, which is calibration factor. I determined the linear range of the QPD to be when the output was in range -50V to 50V, then corresponding displacement range is about 0.2 mm width. Using this result, the PZT mirrors will be calibrated in linear range of the QPD tomorrow. 

Comments:

  • Some X-Y coupling existed. When one axis micrometer was moved, a little signal of the other direction was also generated.
  • As Gautam proposed in the previous study, there is some hysteresis. That process would bring some errors to this result.
  • A scale of micrometer is expressed in INCH!
  • The micrometer I used was made to have 1/2 inch range, but it didn't work well and the range of X-axis was much narrower. 

Reference:
previous experiment by Gautam for X-arm: elog:40m/8873, elog:40m/8884

Attachment 1: QPDcalibrationXaxis.pdf  83 kB  Uploaded Sun Sep 30 22:13:14 2018  | Hide | Hide all
QPDcalibrationXaxis.pdf
Attachment 2: QPDcalibrationYaxis.pdf  83 kB  Uploaded Sun Sep 30 22:13:25 2018  | Hide | Hide all
QPDcalibrationYaxis.pdf
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