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Entry  Wed Aug 13 10:50:04 2014, Andres, Update, IMC, Calculation for the input mode cleaner ModeCleanerSetup0.PNGalaModeModeCleanersolution.png
    Reply  Wed Aug 13 13:08:24 2014, rana, Update, IMC, Calculation for the input mode cleaner 
       Reply  Thu Aug 14 15:10:47 2014, Andres, Update, IMC, Calculation for the input mode cleaner SolutionForTheModeCleanerSetup00.pngSolutionForTheModeCleanerSetup11.pngPossibleSetupForModeCleaner.PNGalaModeSolution.zip
    Reply  Wed Aug 13 22:01:57 2014, rana, Update, IMC, Calculation for the input mode cleaner 
Message ID: 10384     Entry time: Thu Aug 14 15:10:47 2014     In reply to: 10375
Author: Andres 
Type: Update 
Category: IMC 
Subject: Calculation for the input mode cleaner 

Quote:

Can you please give us some more details on how this design was decided upon? What were the design considerations?

It would be nice to have a shorter path length for WFS2. What is the desired spot size on the WFS? How sensitive are they going to be to IMC input alignment? Are we still going to be recentering the WFS all the time?

 I did the calculation, and I reduced the beam Path. In my calculation, I restricted the waist size at the WFSs to be between 1mm-2mm also the other parameter is that the Gouy Phase different between the WFSs have to be 90 degrees. I also try to minimize the amount of mirrors used. I found the Gouy phase to be 89.0622 degrees between the WFSs and the following table shows the solution that I got from a la mode:

 

  label                         z (m)                   type               parameters         
    -----                         -----                    ----                  ----------         
    MC1                    0                        flat mirror           none:            
    MC3                    0.1753               flat mirror           none:            
    MC2                   13.4587              curved mirror    ROC: 17.8700 (m)       
    Lens1                 28.8172              lens                   focalLength: 1.7183(m)
    BS2                    29.9475              flat mirror           none:            
    First Mirror         30.0237              flat mirror           none:            
    Lens3                 30.1253              lens                  focalLength: -0.100 (m)
    Lens2                 30.1635              lens                 focalLength: 0.1250(m)
    WFS1                 30.2269              flat mirror         none:            
    Second Mirror    30.2650              flat mirror         none:            
    Third Mirror       30.5698              flat mirror         none:            
    Lens4                30.8113              lens                  focalLength: -0.075 (m)
    WFS2                31.0778              flat mirror         none:     
       

In the first image attached below is the a la mode solution that show the waist size in the first WFS, and I used that solution to calculate the solution of the waist size for the second WFS, which is shown in figure 2. I photoshop a picture to illustrate how the new setup it supposed to look like. 

Attachment 1: SolutionForTheModeCleanerSetup00.png  14 kB  | Hide | Hide all
SolutionForTheModeCleanerSetup00.png
Attachment 2: SolutionForTheModeCleanerSetup11.png  17 kB  | Hide | Hide all
SolutionForTheModeCleanerSetup11.png
Attachment 3: PossibleSetupForModeCleaner.PNG  20.223 MB  | Hide | Hide all
PossibleSetupForModeCleaner.PNG
Attachment 4: alaModeSolution.zip  2 kB
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