Patent ID: 6188482
Filing Date: 2001-02-13
Classification: G01B

Abstract:
A speckle interferometer for measuring displacement of an optically irregular surface of a specimen comprising:a radiation source for producing a beam of coherent radiation to a first location;an adjustable polarizing beam splitter located at the first location for receiving the radiation from the radiation source and dividing the radiation into a first portion of the radiation and into a second portion of the radiation, and reflecting the first portion of the radiation to a second location, and reflecting the second portion of the radiation to a third location;a first collimator located in the second location for receiving the first portion of the radiation from the beam splitter and collimating and reflecting the first portion of the radiation to a fourth location;a second collimator located in the third location for receiving the second portion of the radiation from the beam splitter and collimating and reflecting the second portion of the radiation to a fourth location;wherein the optically irregular surface of the specimen is located at the fourth location for reflecting the first and second portions of the radiation to a fifth location, the reflection of the first and second portions interfering to form a set of speckles, the speckles moving proportional to the movement of the surface; andan imaging system for recording the speckles and for measuring displacement of the speckles.