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Construction of a Tabletop Michelson Interferometer (view source)
Revision as of 08:43, 17 December 2009
, 08:43, 17 December 2009no edit summary
The pupose of this page is to describe the work being done in the construction of a tabletop Michelson Interferometer. The purpose of this device in the scope of the project is two fold. First, the interferometer can be used to analyze the vibrational characteristics of a diamond waffer suspended from a wire frame. Second, the interferometer can be used to study the surface profle of a diamond waffer, allowing us to see the efects that different cutting and mounting tecniqus have on the final product. The main work does this semister has been on the vibrational aspects of the diamond mounting.
The pupose of this page is to describe the work being done in the construction of a tabletop Michelson Interferometer. The purpose of this device in the scope of the project is two fold. First, the interferometer can be used to analyze the vibrational characteristics of a diamond waffer suspended from a wire frame. Second, the interferometer can be used to study the surface profle of a diamond waffer, allowing us to see the efects that different cutting and mounting techniques have on the final product. The main work does this semister has been on the vibrational aspects of the diamond mounting.
== Construction ==
== Construction ==
===Images of Set-up ===
===Images of Set-up ===
The fllowing are images of the complete Michelson set-up
The following are images of the complete Michelson set-up
IMAGE OF CALIBRATION DEVICE
IMAGE OF CALIBRATION DEVICE
This calibraton device was used to determine the change in pixel location of the center of the lens flairs based on agular displacment. To do this, the camera was mounted horizontally on a 1.40m long bar. The camera end was free to rotate about a pivot located at te opposite end of the rod, above which a mirror was mounted. A linear mcroadjustment translation stage was placed below the camea end.
=== Image Analysis ===
To find the location of the center of the flair on each image, several lines of code were imlimented:
MATLAB CODE
The first line imports the image, in this ase IMAG0001.jpg, convert it to a matrix, and separated the green channel. Next, this matrix is imaged in false color in terms of intensity from blue(low) to red(hgh).
INSERT FALSE COLOR IMAGE ON RIGHT OF THIS PARAGRAPH
The last line is the actual search function. The search functions by finding the location with the smallest difference between the intensity(a(m,n)) and the fit function we apply to image. We use a gaussian distribution with user defined parameters as our fit. The code for this function is:
function out=gauss2(x,y,p)
[xx,yy]=meshgrid(x,y);
out=p(1)*exp(-0.5*((xx-p(2))/p(3)).^2-0.5*((yy-p(4))/p(5)).^2) + p(6);
The parameters p(1) to p(6) are, in numerical order, (1) the amplitude of the function, (2) x location, (3)sigma x, (4) y location, (5) sigma y, and (6) an offset applied to eliminte background noise. The function takes user inputs as an initial guess, then loops the search process to find more accurate values for the parameters. Arbitrary values are chosen for p(1), p(3), p(5) and p(6) to begin, and are then readjusted based on the first output parameters. Typicall, the closer these fit parameters are to the true paramters, the better the functin is at defining p(2) an p(4).
By knowing the change in pixel locaton betwen photos, as well as th angular displacment, a value for pixel change per mrad in the xdiection can be determined. This proess is then repeaed for the y direction. Once these tweo parameters are known, the video analyss can be used to fin both frequency nd amplitude.
* [[Interferograms]]
* [[Interferograms]]
* [[Analysis of heat equation for diamond mounting]]
* [[Analysis of heat equation for diamond mounting]]