STABILIZING DEVICE OF OSCILLATION FREQUENCY OF SEMICONDUCTOR LASER

摘要

PURPOSE:To realize high stability of frequency and set accuracy by carrying out frequency convertion of a frequency of beat signal by local signal, by applying phase continuous frequency modulation to a standard signal for frequency modulation of reference beam and by detecting error signal synchronously by using detection light branched from the reference beam. CONSTITUTION:A frequency of a beat signal BT is converted by a local signal by a mixer 42 of a frequency conversion part 40 and phase thereof is compared with that of a standard signal SS at an offset lock signal generation part 50; and an offset lock signal is thereby detected and fed back to a reference beam frequency variable oscillator 20. Phase continuous frequency modulation is applied to the standard signal SS by a repetition signal RS which is supplied by a modulation signal oscillator 71 and a frequency of output light of a reference laser 21 is modulated through the offset lock signal. Meanwhile, an error signal ES is synchronously detected by the repetition signal RS by a synchronous wave detecting means 62 through an optical synthesizing and analyzing means 31 and an optical frequency recognizing means 61 by repetition signal RS using a detection light DLD containing output light of the reference laser 21 and fed back to a stabilized photo frequency variable oscillator 10. Thereby, oscillation frequency can be stabilized accurately.