PURPOSE: To increase the 2nd higher harmonic conversion efficiency of a waveguide internal resonance type 2nd higher harmonic generating element which converts infrared laser light into visible light and to stabilize oscillation wavelength.
CONSTITUTION: An optical waveguide 4 is formed in an epitaxial thin film on a substrate and a polarization inversion part 3 and a diffraction grating 5 are installed adjacently in the optical waveguide 4; and light from a semiconductor laser 7 is made incident on the polarization inversion part 3 and converted into a 2nd higher harmonic, the following diffraction grating 5 reflects the fundamental wave to the side of the semiconductor laser 7, and only the 2nd higher harmonic is outputted. Further, a voltage is impressed to electrodes provided on the diffraction grating 5 to adjust the semiconductor laser wavelength.
KAWAMOTO KAZUTAMI
KAEDE HIROSHI
KOMODA MIGAKU
