Patent ID: 7778292

Claim:
A laser processing apparatus for directing laser light to a to-be-processed surface for performing desired processing thereon, the laser processing apparatus comprising: a laser medium for creating fundamental-wave laser light with a fundamental frequency; a wavelength conversion device which, if the fundamental-wave laser light from the laser medium is inputted thereto, creates higher-harmonic-wave laser light with a harmonic wavelength of a higher order than the wavelength of the fundamental-wave laser light; a temperature measurement section for measuring the temperature of the wavelength conversion device; a temperature adjustment section for adjusting the temperature of the wavelength conversion device; a temperature control section for controlling the temperature adjustment section for changing the temperature of the wavelength conversion device within a predetermined range; an output monitoring section for measuring the laser power emitted from the wavelength conversion device at each temperature of the wavelength conversion device which is changed in temperature by the temperature control section; and a temperature setting section for setting the temperature of the wavelength conversion device at which the laser power measured by the output monitoring section has a maximum value, as an optimum temperature of the wavelength conversion device.