INJECTION SYNCHRONIZED OR MOPA LASER

摘要

PROBLEM TO BE SOLVED: To provide an injection synchronized or MOPA laser that can always obtain a stable output and wavelength. SOLUTION: This injection synchronized or MOPA laser is provided with an oscillator (11A) which oscillates seed laser beam (21A) which is band- narrowed in wavelength by means of a band-narrowing unit (30) by exciting a laser gas by causing oscillating discharge and an amplifier (11B) which emits laser beam (21B) by amplifying the seed laser beam (21A) by causing amplified discharge. The laser is also provided with a wavelength monitor (34A) which detects at least the wavelength characteristic of the seed laser beam (21A) and a laser controller (29) which controls the wavelength characteristic of the laser beam (21A) within a prescribed permitted limit by performing adjusting oscillation when the laser is started or the laser oscillation is ceased for a prescribed period of time or longer.