CORNER CUBE PHASE-COMPENSATED IN LASER INTERFERENCE METHOD

PROBLEM TO BE SOLVED: To provide a CC retroreflector which copes with the problems concerning the relative polarization rotation, elliptic angle, reflection efficiency, soiling of the conventional corner cube (CC) retroreflector whose phase is compensated in a laser interference method. SOLUTION: A corner cube (CC) retroreflector whose phase is compensated has three backward reflecting faces. The first and third backward reflecting faces can be coated with phase compensation thin film stack that causes a phase difference of 2 nπ (n is an integer including 0) when reflection takes place. Alternatively, all the three backward reflecting faces can be coated with phase compensation thin film stack that causes a phase difference of nπ when light polarized straight is used or a phase difference of 2nπ when light polarized straight or in circle is used. Such coating enables the phase compensation CC to hold the polarization orientation and elliptic angle of incident light. Such phase compensation CC can be used for improving the accuracy of a distance measurement interferometer. The CC guides light to a polarizing beam/splitter 24, a mirror, and other optical elements including a quarter wavelength plate, while it guides light from the other optical elements. COPYRIGHT: (C)2005,JPO&NCIPI