Patent ID: 8050302

Claim:
A wavelength conversion laser light source comprising: a fundamental wave laser light source; a wavelength conversion element for converting a fundamental wave emitted from the fundamental wave laser light source into a harmonic wave, the wavelength conversion element being made of a material whose light absorption properties are subjected to change according to an output level of a harmonic wave; an output setting section for setting a harmonic wave output power value; an element temperature switching section that switches a temperature of the wavelength conversion element to a temperature according to a harmonic wave output level as set in the output setting section, and includes an element temperature holding section that holds said wavelength conversion element at the temperature as switched by said element temperature switching section, said element temperature holding section including a memory for storing therein element temperatures to be held by said element temperature holding section; and an element temperature learning section for learning a temperature of said wavelength conversion element as stored in said memory, to rewrite the currently stored temperature into a temperature as learned, wherein: said element temperature learning section searches for an optimal element temperature at which a harmonic wave of the highest power can be outputted, with a start temperature for said search of a predetermined temperature Δt(° C.) below the temperature of said wavelength conversion element as stored in said memory, and said element temperature learning section carries out said search by increasing the temperature from said start temperature, and stores in said memory the optimal temperature as searched.