Speckle pattern interferometer
First Claim
Patent Images
1. An interferometer comprising:
- a planar mirror having a small aperture formed therein;
an optical imaging system disposed optically between an object location and an image location with said mirror disposed in the optical path between said imaging system and said image location, whereby light scattered from a surface disposed at said object location will be imaged by said imaging system at said image location after reflection at said mirror;
means for producing from a beam of coherent light directed into the interferometer separate object and reference beams;
means for directing said object beam to said object location to illuminate any surface disposed at said object location; and
means for directing said reference beam to said image location, including means for shaping said reference beam so that it will diverge to said image location through said small aperture from an effective point source located behind said mirror at a position such that at any point of said image location the maximum angle between a ray of said reference beam and a ray of said imaged scattered light will be not greater than the maximum angle between different rays of said imaged scattered light.
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Abstract
In a "speckle pattern" interferometer a coherent light beam is split into object and reference beams, the former being directed to illuminate a surface under inspection. Light scattered from this surface is imaged at an image location, at which there may be disposed the screen of a television camera device, the imaged light being reflected to the image location by a planar mirror. The reference beam is directed to the image location to interfere with the imaged light, this beam diverging to the image location from an effective point source located behind the mirror through an aperture in the mirror.
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8 Claims
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1. An interferometer comprising:
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a planar mirror having a small aperture formed therein; an optical imaging system disposed optically between an object location and an image location with said mirror disposed in the optical path between said imaging system and said image location, whereby light scattered from a surface disposed at said object location will be imaged by said imaging system at said image location after reflection at said mirror; means for producing from a beam of coherent light directed into the interferometer separate object and reference beams; means for directing said object beam to said object location to illuminate any surface disposed at said object location; and means for directing said reference beam to said image location, including means for shaping said reference beam so that it will diverge to said image location through said small aperture from an effective point source located behind said mirror at a position such that at any point of said image location the maximum angle between a ray of said reference beam and a ray of said imaged scattered light will be not greater than the maximum angle between different rays of said imaged scattered light. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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Specification