| 摘要 |
<P>PROBLEM TO BE SOLVED: To measure the angle of incidence against a reflecting surface of a measurement beam. <P>SOLUTION: In such a state that a corner cube 53 is inserted in a first measuring path, a beam LB is separated into a P-polarization component (measurement beam) and an S-polarization component (reference beam) by the body portion 49 of an interferometer comprising a separating optical element 49a, and the resultant beam of a return beam from the reflecting surface 26a of the measurement beam and a return beam from a reference mirror 49e of the reference beam are received, via a part region of an FOP 51 via the unshielding region of a light-shielding mechanism 52 by a light-receiving portion. Setting for the light shielding region of the light-reflecting board 52 is changed, and similarly a resultant beam is received via another part region of the FOP 51 by the light-receiving portion. Based on information on the absolute phases of interference signals according to interference beams with the measurement beam and the reference beam contained in the received resultant beams outputted respectively from the light-receiving portions, the angle of incidence against the reflecting surface of the measurement beam is calculated. <P>COPYRIGHT: (C)2007,JPO&INPIT |
