LASER SOURCE APPARATUS

摘要

PROBLEM TO BE SOLVED: To provide a laser light source that can keep the temperature of a wavelength conversion element appropriate for maximum wavelength conversion efficiency and achieve stable optical output without using a light detection device, temperature control means and the like.SOLUTION: A semiconductor laser 2 is turned on, and a heater 7 is turned on to heat a wavelength conversion element 5. A laser beam emitted from the semiconductor laser 2 is wavelength-converted by the wavelength conversion element 5, and the wavelength conversion light is emitted via a fundamental wave light reflective element 4 and a half mirror 10. A light-absorbing face 5a attached to the wavelength conversion element 5 is irradiated with a part of the wavelength conversion light reflected by the half mirror 10, thereby heating the wavelength conversion element 5. The heating by the heater 7 is stopped when the temperature of the wavelength conversion element 5 rises not less than a temperature at which a wavelength conversion efficiency reaches the maximum. The temperature of the wavelength conversion element 5 stably stays in the vicinity of a temperature at which the wavelength conversion efficiency is at a maximum, through increase and decrease of a heating amount by the light irradiating the light-absorbing face 5a accompanied by the increase and decrease of the wavelength conversion light, thus a stable optical output obtained.