| 摘要 |
PURPOSE:To reduce the lateral spread of an injected current in an active layer, by providing a pair of multicrystal layers, with a stripe part left at positions adjacent to the active layer in one clad layer of the clad layers holding the active layer inbetween. CONSTITUTION:Clad layers 4 and 6 are constituted by compound semiconductors having a refractive index which is larger than the refractive index of an active layer 5 and provided on the upper and lower surfaces of the active layer 5. An SiO2 film 3 is formed on the layer 4, with a stripe part 3' remained. Thereafter, a compound semiconductor, which is the same as the layer 4, is grown on the layer 4. Then, a single crystal layer 9 is formed in the part 3' and the upper part thereof. On the film 3, a pair of multicrystal layers 2 are formed on both sides of the layer 9. The layers 2 and the layer 9 act as a clad layer. Therefore the layer 4 can be made thin. The layers 2 can be formed at the positions, which are closer to the layer 5 by the amount of the thickness reduction. When an exciting current is injected, the current is confined in a stripe shape by the layers 2 and injected into the layer 5 under this state. The spread of the injected current in the layer 5 becomes small, and gain increasing wave guidance is effectively generated. |
