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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: 1219     Entry time: Sun Jun 30 22:58:45 2013     In reply to: 1214
Author: Chloe 
Type: DailyProgress 
Category: ECDL 
Subject: Noise Calculations 

I redid the plots from my meeting on Friday with Rana and Tara in Matlab, comparing different components. They are attached here. I'm still trying to get the minor gridlines to show up. 

Plot 1: Comparing noise levels of different experiments to determine which we will use as our standard. 

Plot 2: Comparing noise levels after the ECDL and servo of different diodes. Different diodes have different sizes, which affects the value of parameter X. They are all made of GaAs so other parameters are not affected. We have decided to order the Thorlabs and QPhotonics diodes. The Lumics diode has suspiciously low noise - perhaps the theoretical approximation breaks down in this case. 

Plot 3: Comparing noise levels after the ECDL and servo of different gratings. The gratings are only affected by the efficiency. We will go with the Thorlabs 1200/mm 1um blaze wavelength grating, since we want a blaze wavelength close to the wavelength of light we are selecting for (see Tara's ECDL note on the SVN), and we want as many grooves possible for maximum resolution. 

Plot 4: Comparing noise levels after the ECDL and servo of different cavity lengths. This plot is much better than the Mathematica one; we can see that longer cavities have lower noise, but a smaller FSR. We will likely go with 60-10 cm. 


Also attached is a sketch of our mechanical setup, agreed upon during the meeting on Friday with Rana and Tara. 


This week, I will get a draft of my first report done before the long weekend for Tara to look over. This will probably involve looking over some old concepts to write up something comprehensive. I will also be waiting for a response from QPhotonics and Thorlabs about preselecting diodes, and I need to talk to Dmass about using a current driver. Start looking at metal boxes in the 40m  and building the parts in Solidworks if I have time. 

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Attachment 2: compare_diodes.png  7 kB  | Hide | Hide all
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Attachment 3: compare_gratings.png  9 kB  | Hide | Hide all
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Attachment 4: compare_length.png  8 kB  | Hide | Hide all
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Attachment 5: 100_0068.JPG  1.711 MB  | Hide | Hide all
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