LASER APPARATUS AND SECOND-HARMONIC GENERATION METHOD

摘要

PURPOSE:To provide a method, for SHG, wherein its output fluctuation is small and its efficiency is high without additionally inserting an optical element increasing a reflection loss into an optical resonator and to provide a laser device. CONSTITUTION:A semiconductor-laser excitation solid-state laser device is provided with a means 5 which controls the temperature of a solid-state laser crystal 3 in such a way that a phase difference caused when fundamental waves are transmitted through the solid-state laser crystal 3 becomes (2mpi+3pi/ 2) and with a means 9 which controls the temperature of a nonlinear optical crystal in such a way that a phase difference caused when the fundamental waves are transmitted through the nonlinear optical crystal 7 becomes (2m'pi) [where (m) and (m') are integers] or a method for SHG by the phase matching of type II uses the means 5 and the means 9.