Patent ID: 6529278
Filing Date: 2003-03-04
Classification: G01B

Abstract:
An optical interference apparatus comprising:a light source; a beam splitter for splitting a light beam from said light source; a reference surface by which one split light beam from said beam splitter is reflected to propagate backward through the optical path, the light beam from said reference surface and the other split light beam which emerges from said beam splitter, is reflected by an object to be detected, and returns, being combined by said beam splitter and the combined light being finally used as interference light, and the two split light beams emerging from said beam splitter as convergent light; and an optical element having a function of converging a light beam or changing a divergent state of the light beam, said optical element being inserted in an optical path of one of the split light beams emerging from said beam splitter, and the reflected light beams from converging positions of the two split light beams being combined at said beam splitter as spherical waves with curvatures equal to each other owing to an effect of said optical element.