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Entry  Mon Dec 20 19:55:11 2010, tara, DailyProgress, optic, rearraging optics for beat measurement 
    Reply  Thu Dec 23 22:41:28 2010, tara, DailyProgress, optic, rearraging optics for beat measurement 
       Reply  Sun Dec 26 02:42:47 2010, tara, DailyProgress, optic, rearraging optics for beat measurement 
          Reply  Mon Dec 27 02:51:33 2010, tara, DailyProgress, optic, rearraging optics for beat measurement beat_2010_12_27.png
Message ID: 440     Entry time: Thu Dec 23 22:41:28 2010     In reply to: 437     Reply to this: 441
Author: tara 
Type: DailyProgress 
Category: optic 
Subject: rearraging optics for beat measurement 

Beat measurement optics' height is changed to 3". I cleaned all optics already, but I couldn't really clean 1/2 and 1/4 wave plates, one of the f =200 mm lens is quite hard to clean.

I'll wait and ask someone before trying to clean again. I cannot lock both cavities at the same time, once I can, I'll align the beam on the PD.

Also ACAV's PD for ACAV_trans_PD is broken. It gives out 11 V regardless of the beam falling on the PD, so I replace it with a PD that is used for NPRO_PWRMON.

 

Quote:

I designed the layout for optics behind the cavities for beat measurement, and calculated the mode matching for the beam.

Since the current optics height for beat is quite high (7 inches), we want to lower it to 3 inches, make it more symmetric, and more compact.

The PD's diameter is 300 mm, so the beam spot on it will be ~50um.

All the lenses I need are prepared.

 

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