| 摘要 |
PURPOSE:To feedback part of a light irradiated from an active layer by a diffraction grating and to irradiate the part of the light perpendicularly to a semiconductor substrate thereby to eliminate the displacement of the position of a condensed spot of the irradiated light by integrating an active region including at least the active layer and a two-dimensional optical wave guide having a diffraction grating on the substrate. CONSTITUTION:An n-type AlGaAs clad layer 12, an n-type GaAs active layer 13, a p-type AlGaAs clad layer 14 and a P<+> type GaAs cap layer 15 are laminated on an n-type GaAs substrate 11 to form an active region 16 of buried structure. A diffraction grating 17 is formed on a two-dimensional optical wave guide 18. The light irradiated from the region 16 is coupled with the wave guide 18 to be conducted, the light of specific wavelength determined by the pitch by the grating 17 is fed back to the region 16 to be oscillated in a single mode in the wavelength. The light of the specific wavelength is partly irradiated perpendicularly to the substrate 1 by the grating 17. Since the stable single mode oscillation is generated, even if the irradiated light is condensed, the displacement of the spot does not occur. |
