HETERO MODE HELIUM-NEON LASER AND HETERODYNE LASER INTERFEROMETER BY USING SUPER HETERODYNE PHASE MEASUREMENT

摘要

PURPOSE: A hetero mode helium-neon laser and a heterodyne laser interferometer are provided to measure displacement of a moving object by using super heterodyne phase measurement. CONSTITUTION: A heterodyne laser interferometer includes a laser source section(70), an optical interferometer section(60), a frequency converting section(80), and a phase measuring device. The laser source section(70) includes a hetero mode helium-neon laser generator(71). Light generated from the laser source section(70) has two frequencies. A part(74) of light generated from the laser source section(70) is used as a reference signal and other light(75) generated from the laser source section(70) is used as a measuring signal. The reference signal is converted into an electric signal(76) through a photo detector(73).