PURPOSE: To increase conversion efficiency, and realize high density integration by arranging a second harmonic wave generating region composed of II-VI compound semiconductor crystal, on a semiconductor laser layer composed of III-V compound semiconductor, and providing a diffraction grating at a position, in the region, where laser light diffracted by a diffraction grating in a semiconductor laser arrives.

CONSTITUTION: A second harmonic wave generating region (SHG region) II is constituted of II-VI compound semiconductor crystal. For example, epitaxial growth is enabled on an AlGaAs system semiconductor laser, and the SHG region II can be easily formed in a unified body. Since the fundamental wave from the semiconductor laser I couples with the SHG region II without passing the external space, the intensity of the fundamental wave can be increased. By a diffraction grating GI in the semiconductor laser I, the fundamental wave generated from the semiconductor laser I is diffracted in the direction of the SHG region II and introduced. By diffracting the introduced fundamental wave with a diffraction grating GII in the SHG region II, the fundamental wave is effectively converted into the second harmonic wave. Thereby high density integration is enabled, and the conversion efficiency is increased.