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Entry  Thu Jul 16 04:59:38 2009, Dmass, Laser, PSL, Razor Blades! Photo_1.jpgPhoto_3.jpg
    Reply  Thu Jul 16 15:01:48 2009, Koji & Connor , Laser, PSL, Razor Blades! 
       Reply  Thu Jul 16 17:43:59 2009, Dmass, Laser, PSL, Razor Blades! 
          Reply  Mon Jul 20 23:19:49 2009, rana, Laser, PSL, Razor Blades! 
             Reply  Tue Jul 21 20:41:56 2009, Dmass, Laser, PSL, Razor Blades! 
    Reply  Fri Jul 17 15:39:31 2009, Dmass, Laser, PSL, Razor Blades! RazorScans.pdf
Message ID: 182     Entry time: Fri Jul 17 15:39:31 2009     In reply to: 177
Author: Dmass 
Type: Laser 
Category: PSL 
Subject: Razor Blades! 

Quote:

Since the beamscan is in a questionable state of scanny goodness, Koji advised that I do some razor blade occlusion power measurements of the beam and then fit an erf to it to find the waist. I took data with the tinker toys pictured below.

I will compare these results with some beamscans results to verify (hopefully) that the beamscan is outputting useful results, not lies.

 Using the setups in the quoted post, I took manual beamscans 23" in front of the PSL enclosure, before the first steering mirror, and fit P = A erf(B*x + C)

 I measured the relative position of my razorblade with a micrometer and calculated the error from an estimated uncertainty of it's angle. This seemed to agree with repeatability of measurements for a given experimental state. Uncertainty < .002"

I watched the Power meter for ~ 60 seconds for each measurement, it fluctuated around some point and seemed to not be drifting @ DC, so the upper and lower error bars of each point included are the bounds of the fluctuation of the power meter. These were less than +/- 5mW about my points, so a fractional uncertainty of about 2% at my maximum power.

 

I got waists of:

Vertical: 799 +/- 4.5 microns

Horizontol 827 +/- 1.2 microns

Attached plot includes data w/ error and functional form of fit

 

As expected, my Chi^2 is "bad" since I am fitting the input beam to the PMC with a 00 mode description of the waist, which ignores all higher order modal content.

Attachment 1: RazorScans.pdf  16 kB  Uploaded Tue Jul 21 21:21:07 2009  | Hide | Hide all
RazorScans.pdf
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