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Entry  Wed Apr 21 10:09:23 2010, kiwamu, Update, Green Locking, waist positon of Gaussian beam in PPKTP crystals focal_positin_edit.png
    Reply  Tue Apr 27 14:18:53 2010, kiwamu, Update, Green Locking, waist positon of Gaussian beam in PPKTP crystals mode_in_PPKTP.png
       Reply  Thu Jul 29 21:13:39 2010, Dmass, Update, Green Locking, waist positon of Gaussian beam in PPKTP crystals 
          Reply  Thu Jul 29 22:58:25 2010, kiwamu, Update, Green Locking, waist positon of Gaussian beam in PPKTP crystals 
             Reply  Fri Jul 30 00:02:15 2010, Dmass, Update, Green Locking, waist positon of Gaussian beam in PPKTP crystals 
                Reply  Fri Jul 30 09:51:58 2010, kiwamu, Update, Green Locking, Re: waist positon of Gaussian beam in PPKTP crystals efficiency_waist_edit.pngPPKTPmode.pngPSL_doubling.pngmode_in_PPKTP.png
Message ID: 3330     Entry time: Fri Jul 30 09:51:58 2010     In reply to: 3328
Author: kiwamu 
Type: Update 
Category: Green Locking 
Subject: Re: waist positon of Gaussian beam in PPKTP crystals 

Okay, I guess I understand what you want to know. I did the following steps.

1. calculated the conversion efficiency as a function of the waist size. I found w~50um was the optimum waist.

  Note: the confocal relation Zr = pi * wo^2/(lamba/n) = L/2  gives us almost the same optimum waist. 

elog #2735

efficiency_waist_edit.png

  2.  Did mode matching to get w=50um

elog #2959

elog #3188

PPKTPmode.png

PSL_doubling.png

  3. calculated the offset

elog #2850

mode_in_PPKTP.png 

 4. Moved the ovens

 

Quote:

I thought we cared about satisfying the confocal focusing parameter, that is to say we want to set Zr = 2L_crystal. If Zr changes inside the crystal, this is the number we care about..isn't it NOT the waist size, but the rayleigh range we care about? I am not entirely sure what youre response is saying you did...

  1. Calculate Zr = pi * wo^2/(lamba/n)
  2. Do mode matching to get this wo in free space
  3. Calculate the offset you need to move the oven by using n
  4. Move hte ovens

OR

  1. Calculate Zr = pi*wo^2/(lamba)
  2. Do mode matching to get this in free space
  3. Calculate the offset you need to move your ovens using n
  4. Move your ovens

I guess the waist size would also let me know - are you using 69 um or 53 um waist size?

 

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