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Entry  Mon Sep 17 20:23:31 2012, Jenne, Update, General, Last of In-vac mirror photos taken 
    Reply  Mon Sep 17 23:58:01 2012, rana, Update, General, Last of In-vac mirror photos taken 
       Reply  Thu Sep 20 14:55:06 2012, Jenne, Update, General, Pickoffs are hard to see 
          Reply  Thu Sep 20 19:56:05 2012, Jenne, Update, General, Pickoffs are hard to see 
    Reply  Tue Sep 18 11:53:12 2012, Jenne, Update, General, Last of In-vac mirror photos taken AllPhotos_Sept2012.pdf
       Reply  Wed Sep 19 01:15:15 2012, Jenne, Update, General, Last of In-vac mirror photos taken - NOT! 
Message ID: 7420     Entry time: Thu Sep 20 14:55:06 2012     In reply to: 7400     Reply to this: 7422
Author: Jenne 
Type: Update 
Category: General 
Subject: Pickoffs are hard to see 

Quote:

 My hope is that the DRMI flashes will be bright enough to see on the PO beams. IF we get 10 mW through the Faraday, you should get some buildup when the carrier resonates in the DRMI.

If the recycling gain is 10 and the pickoff fraction is 100 ppm you ought to get ~10 uW on PO. How much of the recycling cavity power gets out of POP?

 [Manasa, Jenne]

We think this math is wrong.

If we have P mW through the Faraday, PRM's transmission is 5.5%, BS transmission is 50%, Recycling gain is ~10, pickoff fraction is ~100ppm, we have:

P mW * 5.5e-2 * 0.5 * 10 * 100e-6 = P * 2750e-8 mW = P * 2.7e-5 mW.

So, if P=10 (10mW through the Faraday), we should have 2.7e-4 mW = 2.7e-7 W = 0.27 microwatts = not so many watts.    

If P = 100 (100mW through the Faraday), we should have 2.7 microwatts. Still, not so many watts.

We have the Watec pointed at POY right now, DRMI is flashing, I'm waving the IR card in front of the mirror, and Manasa isn't able to see anything on the monitor.  The power into the vacuum is 100mW (we just measured and adjusted it), so even if we were getting a full 100mW through the Faraday, it would be hard to see.  If we're assuming we get ~half the power through the Faraday, then we should only have 1 microwatt

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