DISPLACEMENT DETECTION APPARATUS, DISPLACEMENT GAUGING APPARATUS, AND FIXED POINT DETECTION APPARATUS

摘要

PROBLEM TO BE SOLVED: To enable accurate fixed point detection and displacement gauging, by reducing the disturbances of polarized waves due to the stress and the buckling of the optical fiber for transmitting a light emitted from a light source to a detecting side.;SOLUTION: Coherent or low-coherent light emitted from the light source 12 becomes, when coming into a polarizing plate 13, a linearly polarized light with high extinction ratio such as 30dB. The linearly polarized light with high extinction ratio is condensed by a condenser lens 14, and is made to come into a polarization retention type optical fiber 15 while the polarization axis of the linearly polarized light beam is matched with the optical axis of the polarization retention type optical fiber 15. Thus, when the beam converted into the linearly polarized light by the polarizing plate 13 is made to come into the polarization retention type optical fiber 15, matching the polarization axis of the beam with the optical axis 34 of the optical fiber 15 can reduce the fluctuation of the extinction ratio due to the buckling or stress of the optical fiber 15.;COPYRIGHT: (C)2006,JPO&NCIPI