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Entry  Tue Feb 20 13:59:30 2018, Koji, Update, General, Modulation depth measurement for an aLIGO EOM 
    Reply  Thu Feb 22 16:11:14 2018, Koji, Update, General, aLIGO EOM crystal replacement IMG_3421.JPGIMG_3426.JPGIMG_3427.JPG
       Reply  Thu Feb 22 17:19:47 2018, Koji, Update, General, Modulation depth measurement for an aLIGO EOM IMG_3436.JPGmodulation_depth.pdfmodulation_linearity.pdfmodulation_24MHz.pdf
          Reply  Mon Apr 2 15:14:21 2018, Koji, Update, General, Modulation depth measurement for an aLIGO EOM modulation_depth.pdfimpedance_eom.pdf
Message ID: 13650     Entry time: Thu Feb 22 16:11:14 2018     In reply to: 13642     Reply to this: 13652
Author: Koji 
Type: Update 
Category: General 
Subject: aLIGO EOM crystal replacement 

aLIGO EOM crystal replacement

  • The entire operation has been performed at the south flow bench @40m.
  • We knew that the original crystal in the aLIGO EOM we are testing has some problem. This was replaced with a spare RTP crystal.
  • Once the housing was removed, it was obvious that the crystal has a crack (Attachment 1).
    It seemed that it was produced by either a mechanical stress or a thermally induced stress (e.g. soldering).
  • I wanted to make sure the new crystal is properly aligned interms of the crystal axis.
    The original crystal has the pencil marking at the top saying "Z" "12". The new (spare) crystal has "Z" and "11".
    So the new crystal was aligned in the same way as the original one. (Attachment 2)
  • I took an opportunity to measure the distribution of the electrode lengths (Attachment 3). The lengths are 14, 5, and 14mm, respectively.
Attachment 1: IMG_3421.JPG  4.651 MB  | Hide | Hide all
IMG_3421.JPG
Attachment 2: IMG_3426.JPG  5.436 MB  | Hide | Hide all
IMG_3426.JPG
Attachment 3: IMG_3427.JPG  5.195 MB  | Hide | Hide all
IMG_3427.JPG
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