Oscillation measuring method and frequency measuring apparatus

摘要

The present invention provides an oscillation measuring method comprising: a laser beam emission step S1 for emitting a laser beam to an object to be measured; a return beam reception step S2 for receiving a return beam reflected by the object and having an object Doppler frequency according to a velocity of the object; a self-mixing step S3 for mixing the return beam having the Doppler frequency with another beam emitted upon reception of the return beam and generating a self-frequency according to a resonator change during a time from the emission to the reception of the return beam, so as to generate a beat wave containing the object Doppler frequency superposed with the self-frequency; and an oscillation information output step S4 for outputting the beat wave or information obtained from signal processing of the beat wave as the object oscillation information. This enables to measure a fine oscillation of an object to be measured.