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Entry  Tue May 4 12:06:37 2010, Zach, Laser, GYRO, 6-m mirrors are OK--back to the drawing board  
    Reply  Wed May 5 15:09:35 2010, Zach, Laser, GYRO, 6-m mirrors are OK--back to the drawing board  
Message ID: 748     Entry time: Tue May 4 12:06:37 2010     Reply to this: 749
Author: Zach 
Type: Laser 
Category: GYRO 
Subject: 6-m mirrors are OK--back to the drawing board  

 Before doing the full T vs. angle test on the 6-m mirrors we have been using (so that we could send them back to CVI), I figured I would just test them at 45°, outside of the cavity, using the same simple configuration I used to measure the new 9-m mirror. What I found was that---for both 6-m mirrors---the transmission was in the range of 50 - 100 ppm, roughly independent of angular tuning away from 45° on the order of +/- 5°. This is pretty much consistent with the part specifications from CVI for Y1S, especially considering that they have been on our table for a couple months.

So.. why did we observe a disproportionate amount of light escaping these mirrors with the cavity locked? Good question. We suspect that it might have something to do with polarization issues, as a macroscopic polarization shift in the cavity would certainly account for the spurious transmission.

I don't know much about what could cause this, but I am reading. The good news is that our mirrors are all what they are supposed to be (yippidy doo da).

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