POLARIZATION SPLITTING SECTION OF POLARIZATION-SPLIT INTERFEROMETER, THE POLARIZATION-SPLIT INTERFEROMETER, AND POLARIZATION-SPLIT INTERFEROMETER TYPE LENGTH MEASURING DEVICE

摘要

PROBLEM TO BE SOLVED: To reduce cost, and simplify adjustment by reducing the optical components of a polarization-split interferometer.;SOLUTION: In the polarization-split interferometer which branches light emitted from a light source 102 into measuring light and reference light, performs polarization splitting of light acquired by reflecting the measuring light with a reflection mirror and the reference light by a first polarization beam splitter 105 and makes them interfere; a second polarization beam splitter 106 for performing polarization splitting of transmitted light of the measuring light and reflected light of the reference light, is arranged with its reflection surface directed to a direction to be indicated when rotated by 45 degrees around an incident light axis from a reference position; a third polarization beam splitter 107 for performing polarization splitting of the reflected light of the measuring light and transmitted light of the reference light, is arranged with its reflection surface directed to a direction to be indicated when rotated by 45 degrees around its incident light axis from a reference position; and the outputs of the second and third polarization beam splitters, each of which is interference light between the measuring light and the reference light, are optically detected.;COPYRIGHT: (C)2010,JPO&INPIT