LASER DEVICE FOR PROCESSING USING NONLINEAR CRYSTAL OF TYPE 1

摘要

PROBLEM TO BE SOLVED: To diminish fluctuations of the output power of a laser beam with a laser device for processing which emits laser beam subjected to wavelength conversion by using nonlinear optical crystals. SOLUTION: Fundamental waves emitted from a basic wave laser beam source 11 is made incident on the first nonlinear optical crystal 13 for double wave generation. The nonlinear optical crystal 13 generates the double wave and the basic wave. The basic wave and double wave emitted from the nonlinear optical crystal 13 are made incident on a wavelength plate 20. The wavelength plate 20 rotates the polarization directions of the basic wave in the direction parallel with the polarization direction of the basic wave and double wave. The double wave and basic wave of the parallel polarization directions emitted from the wavelength plate 20 are made incident on the second nonlinear optical crystal 13' of TYPE1, where the double wave and the basic wave are subjected to wavelength conversion and a triple wave and the fundamental wave are emitted. Since the crystal of the TYPE1 is larger in temperature permissible range width than that of a crystal of TYPE 2, the fluctuations in the output powder of the laser beam can be diminished even if a minor temperature change occurs in the crystals by using only the crystal of TYPE1.