Patent ID: 7830932

Claim:
An internal resonator type SHG light source, comprising: a pump light source which emits a pump light; a solid-state laser which absorbs the pump light and which emits a fundamental wave; an output mirror provided so as to face the solid-state laser, which forms a resonator together with the solid-state laser; a wavelength conversion element provided in said resonator, which converts the fundamental wave into a harmonic wave; a detector which detects a temperature of said wavelength conversion element; and a rotating unit which changes an incident angle of the fundamental wave on said wavelength conversion element by rotating said wavelength conversion element, wherein said rotating unit rotates said wavelength conversion element according to the temperature of said wavelength conversion element as detected by the detector; wherein the wavelength conversion element is made of Mg-doped lithium niobate crystal; wherein a polarization reversal region formed in said wavelength conversion element forms a predetermined inclination angle with respect to an end surface of the wavelength conversion element on the side of the solid-state laser; wherein the predetermined inclination angle is in a range of from 2° to 30°; wherein said wavelength conversion element has a length in a range of from 0.3 mm to 2 mm.