GRAZING INCIDENCE INTERFEROMETER DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a grazing incidence interferometer device capable of forming substantially equal optical path lengths of reference beam and measuring beam after outgoing radiation from a collimator lens until composition by a luminous flux dividing and composite means made of a single member using a low coherence light source and preventing the generation of interference fringe noise due to light reflected from a rear surface of an object to be detected and having satisfactory interference fringe measuring precision and a compact property. SOLUTION: Luminous flux from a light source part 10 enters the luminous flux dividing and composite means 1 provided with a half mirror on its rear surface through the collimator lens 15, a part of bundle of rays entering a counterclockwise divided section 3 becomes reference beam 4aCC, and a part of bundle of rays entering a clockwise divided section 2 becomes measuring beam 5aC. The reference beam 4aCC is made to irradiate a reference face 16a through a compensation plate 12 so as to become reference beam 4bCC, and the measuring beam 5aC enters a face 17a to be detected obliquely so as to become measuring beam 5bC carrying the information of the face to be detected. The reference beam 4bCC and the measuring beam 5bC are made composite on a half mirror face in the counterclockwise divided section 3, and interference fringe due to the composite beam is superimposed on an image of the face to be detected on a CCD light receiving face 11 by the collimator lens 15.