LASER INTERFEROMETER, AND LASER INTERFEROMETRY

摘要

PROBLEM TO BE SOLVED: To provide a laser interferometer and laser interferometry for suppressing the manufacturing cost and eliminating the influence of modulation.;SOLUTION: This laser interferometer measures a length based on laser light interference. The laser interferometer comprises a laser light producing section 10 for producing a laser light L1 modulated with a modulation signal Sg4 of a modulation frequency fm; an interferometer unit 20 for radiating the laser light L1 from the laser light producing section 10 to a moving mirror 30 to produce laser light L4 containing length measurement information and receiving the laser light L4 at a light receiving section 20b to create first and second electric signals ϕA and ϕB containing length measurement information; and a sampling unit 40 for sampling the first and second electric signals ϕA and ϕB in synchronization with a timing signal Sg8 of a sampling frequency fs produced on the basis of the modulation signal Sg2 of the modulation frequency fm.;COPYRIGHT: (C)2010,JPO&INPIT