Optical frequency stabilizer and optical frequency selector

摘要

An optical frequency stabilizer comprises a signal light source for outputting signal light of a frequency fs; a frequency shifter having a pumping light source to emit pumping light of a frequency fp and producing converted signal light of a frequency 2fp-fs from the signal light supplied thereto; a frequency discriminator for converting a frequency change of the received converted signal light into an intensity change; an optical detector for producing a detection signal in response to the output light of the frequency discriminator; an oscillator for outputting a low-frequency signal; a modulator circuit for frequency-modulating the signal light source in accordance with the low-frequency signal; a synchronous detector circuit connected operatively to the oscillator and the optical detector; an inverter circuit for inverting the output characteristic of the synchronous detector circuit; and a control circuit for controlling the signal light source in such a manner as to maintain constant the output level of the synchronous detector circuit. This optical frequency stabilizer has high frequency stability.