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Entry  Thu Jun 20 17:23:40 2013, Chloe, DailyProgress, ECDL, Noise Calculations saito.pdfpsd_noise.png
    Reply  Fri Jun 21 16:47:30 2013, Chloe, DailyProgress, ECDL, Noise Calculations Noise.pdf
       Reply  Mon Jun 24 11:14:04 2013, Chloe, DailyProgress, ECDL, Noise Calculations Noise.pdf
          Reply  Mon Jun 24 17:48:30 2013, Chloe, DailyProgress, ECDL, Noise Calculations Noise.pdf
             Reply  Tue Jun 25 14:14:17 2013, rana, DailyProgress, ECDL, Noise Calculations 
                Reply  Tue Jun 25 17:51:34 2013, Chloe, DailyProgress, ECDL, Noise Calculations Noise2.pdf
                   Reply  Wed Jun 26 17:13:21 2013, Chloe, DailyProgress, ECDL, Noise Calculations Noise2.pdf
                      Reply  Fri Jun 28 14:52:11 2013, tara, Notes, ECDL, laser noise requirement for locking to a refcav 
                      Reply  Sun Jun 30 22:58:45 2013, Chloe, DailyProgress, ECDL, Noise Calculations compare_experiments.pngcompare_diodes.pngcompare_gratings.pngcompare_length.png100_0068.JPG
Message ID: 1202     Entry time: Fri Jun 21 16:47:30 2013     In reply to: 1200     Reply to this: 1206
Author: Chloe 
Type: DailyProgress 
Category: ECDL 
Subject: Noise Calculations 

Today, I wrote up my noise calculations in a nicer way so that I have it on hand in the future. They are attached here. I found a mistake from the last elog entry, so it turns out that we are looking at a linewidth of about 440 kHz (or a PSD noise of 191 Hz/rtHz). This still meets the requirements of the experiment, and can be adjusted as necessary, since I can still increase the length of the cavity to decrease the noise. 

LIGO students had another presentation by Dr. Weinstein about the general progress of the LIGO project this afternoon. There was some discussion of decreasing noise level and aLIGO. 

Just musing: There is some discussion of using a lens to focus the beam (e.g. Saito paper, Saliba paper). I'm not sure how this will affect the noise levels; it might be possible to decrease the noise on the ECDL a lot if we include a lens that focuses the beam? In the Saito paper, they talked about having the beam aligned to focus at 10 m, with a lens of 15 mm focal length. Tara hasn't been around today but I want to talk to him about the idea, because it could affect the noise level. Alternately, multiple mirrors to redirect the beam and make the cavity longer before hitting the grating, although this sounds more complicated. 

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