HIGHER-HARMONIC OUTPUT CONTROL METHOD AND SHORT- WAVELENGTH LASER BEAM SOURCE USING THE SAME

摘要

PROBLEM TO BE SOLVED: To stabilize optical characteristics of emitted higher harmonics converted when the fundamental wave from a short-wavelength laser beam source using a semiconductor laser is made incident on a light wavelength converting element and converted into the higher harmonics. SOLUTION: The semiconductor laser beam P1 is made incident on an optical wavelength 2 of the wavelength converting element 22 having a polarization inversion area 3 and the optical waveguide 2 on an LiTaO3 substrate, and its wavelength is converted to obtain blue light. At this time, the driving current of a DBR 40 of a DBR semiconductor laser 21a is varied and the oscillation wavelength of the semiconductor laser 21a is adjusted to the phase matching wavelength of the light wavelength converting element 22 to control the generated harmonics P2 fixedly. Consequently, even if the ambient temperature varies, the wavelength of the semiconductor laser is constant and a stable operation is carried out.