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Entry  Fri May 9 01:36:28 2014, rana, Summary, SUS, Optical Lever QPD Sum trends: they're almost all too weak OLtrend.png
    Reply  Mon May 12 22:42:19 2014, rana, Summary, SUS, Optical Lever QPD Sum trends: they're almost all too weak OL-FB.pngarms_140512.pdf
       Reply  Mon May 12 22:52:59 2014, Jenne, Summary, SUS, Optical Lever Filters are all different OpLevFilters.pdf
       Reply  Tue May 13 13:27:58 2014, Steve, Summary, SUS, Optical Lever Servos setting table OLsums.png
          Reply  Tue May 13 17:03:05 2014, Steve, Summary, SUS, ETMX oplev laser replaced 
             Reply  Tue May 13 17:31:32 2014, Jenne, Summary, SUS, ETMX oplev laser replaced: New oplev gains set OLerr_13May2014.pdfOLfb_13May2014.pdf
                Reply  Tue May 13 22:55:57 2014, Jenne, Summary, SUS, ETMX oplev: cleanup 
             Reply  Wed May 14 10:04:06 2014, Steve, Summary, SUS, oplev laser and temperature TempRules.png
                Reply  Tue May 20 09:12:25 2014, Steve, Summary, SUS, ETMX oplev qpd board ETMXOLQPD121.jpgETMXOLQPDface121.jpgETMXolSUM.png
                   Reply  Tue May 20 15:54:39 2014, rana, Summary, SUS, ETMX oplev qpd board 
Message ID: 9934     Entry time: Fri May 9 01:36:28 2014     Reply to this: 9942
Author: rana 
Type: Summary 
Category: SUS 
Subject: Optical Lever QPD Sum trends: they're almost all too weak 

 We want there to be ~16000 cts of signal per quadrant on the optical levers. I think that most of the QPDs have been modified to have 100k transimpedance resistors.

From the attached 90 day trend, you can see that the ETMX, BS, PRM, and SRM are really low. We should figure out if we need to change the lasers or if the coating reflectivities are just low.

Steve, can you please measure the laser powers with a power meter and then reply to this entry?

Another possibility is that we are just picking a dim beam and a brighter one is available.

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