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Entry  Fri Jul 22 20:51:13 2011, frank, tara, DailyProgress, optic, cleaning opto mechanical parts IMG_1862.JPGIMG_1863.JPG
    Reply  Tue Jul 26 18:42:16 2011, raphael, tara, DailyProgress, optic, cleaning opto mechanical parts IMG_1866.JPGIMG_1867.JPG
       Reply  Thu Jul 28 01:54:21 2011, frank, tara, DailyProgress, optic, cleaning opto mechanical parts 2011_07_28.pngIMG_1869.JPGIMG_1874.JPGIMG_1875.JPG
          Reply  Fri Jul 29 00:42:19 2011, frank, tara, DailyProgress, optic, cleaning opto mechanical parts IMG_1880.JPGIMG_1883.JPGIMG_1889.JPGIMG_1886.JPGIMG_1878.JPG
             Reply  Tue Aug 2 23:58:40 2011, tara, DailyProgress, optic, New RCAV setup is locked IMG_1911.JPGrcav_2011_08_02.jpg
                Reply  Tue Aug 9 00:39:30 2011, tara, DailyProgress, optic, RCAV modematching optimized 
                   Reply  Mon Aug 15 23:13:53 2011, tara, DailyProgress, optic, RCAV modematching optimized 2011_08_15.png
                      Reply  Wed Aug 17 20:41:13 2011, tara, DailyProgress, optic, ACAV path is up layout_2011_08_17.jpg
Message ID: 658     Entry time: Mon Aug 15 23:13:53 2011     In reply to: 653     Reply to this: 659
Author: tara 
Type: DailyProgress 
Category: optic 
Subject: RCAV modematching optimized 

 I recalculated the mode matching so that the spot radius in AOMs is 100 um. Now the visibility of RCAV is 90%.

     From the previous mode matching calculation, the spot radius in AOM is 220 um. This was too large for ISOMET AOM and caused beam distortion. The AOM was designed for much smaller spot radius (50 - 110 um). So I recalculated to make the spot radius inside the AOM to be 100 um. This spotsize is small enough for ISOMET and not too small for Crystal Tech AOM.

Rise time is 35 ns (28.5MHz) for 100 um radius in ISOMET AOM, diffraction eff ~80%. This should be sufficient for our less than 1MHz bandwidth loop.

 

For the new layout, I have to remove the Faraday isolator behind the EOM for another lens. I'll try to intall it back later.

 

 

 

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