PURPOSE: To stably emit the second higher harmonic beams in high output even if an anisotropical crystal is used as a solid state laser medium by a method wherein the azimuth in the abnormal direction of a 1/4 wavelength plate is set up to make an angle of 45° with the abnormal beam direction of a KTP crystal.
CONSTITUTION: A 1/4 wavelength plate 7 for controlling the alteration of basic laser beam is set up to make an angle of 45° with a KTP crystal 6. Next, the basic laser beams radiated from a solid state laser medium 5 and passing through the KTP crystal 6 and the 1/4 wavelength plate 7 are reflected by a resonator mirror 4 and then reversely passing through the optical path again to be feedback to the solid state laser medium 5 while being amplified by the inductive-radiation in the solid state laser medium 5 to be reflected by the resonator mirror 4 coating 5a on the exciting side end surface of the solid state laser medium 5 for reciprocation in the resonator. Through these procedure, the title solid laser device can be oscilated. Accordingly, even if an anisotropical crystal such as Nd:YVO4 is used as the solid state laser medium 5, the second higher harmonic in high output can be stably emitted.
DAIMON MASAHIRO
YAMAGUCHI SATORU
