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Intro:

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Links:

• 06nov13: 2d fit to diode laser beam.
  

06nov13: 2d gauss fit to laser beam pattern.

• z=c0 + A0*exp( -(xp*xp)/sigx^2 - (yp*yp)/sigy^2 )
• first remove the x,y offsets
  
• xm=x - x0
• ym=y - y0
  
• Then correct for the rotation of the ellipse.
  
• xp  = xm*cos(th)  + ym*sin(th)
• yp = -xm*sin(th)  + ym*cos(th)
• The fit values were:

• coef	value	Description
  c0	5.83	z offset
  A0	1240.31	amplitude
  x0	283.45	xoffset for center. X went from 0 to 640
  y0	300.37	yoffset for center Y went from 0 to 479
  FWHM X	115.99	fwhm for x dimension
  FWHM Y	177.71	FWHM for y dimension
  theta	-.13	degrees rotation of major axis.

• The fwhm is the Full width at half maximum of the Gaussian. . .6006 goes from fwhm to sig.

• Page 1: contour maps of beam shape and fit
• The raw data is black, the 2d fit is in red
• The contours are spaced by 3db
  
• Page 2: strips the x and y peaks of the gaussian
• black is the raw data, red is the fit.

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