| 摘要 |
PURPOSE:To obtain a DFB type semiconductor laser element, which can be formed by simple processes and is operated at high differential quantum efficiency, by forming both side surfaces of an active layer in a wave shape having a constant period in the direction of stripes. CONSTITUTION:For example, on an N-type InP substrate 31 as a basis, a mesa type laminated body 41 in a stripe shape is provided. The laminated body 41 is composed of the following layers: e.g., an N-type InP layer 33 as a lower clad layer; e.g., a GaInAsP layer 35 as an active layer; e.g., a P-type InP layer 37 as an upper clad layer; and e.g., a P-type GaInAsP layer 39 as a cap layer. Both side surfaces 43 of the laminated body 41, which are in parallel in the stripe direction, are made to be of a wave shape, in which protruded parts and recessed parts appear at a constant period in the stripe direction. It is suitable that the wave shape of both side surfaces 43 is formed in such a way that, e.g., the recessed part and the recessed part face each other on the side of the laminated body at the same positions of facing side surfaces. Furthermore, it is suitable that both side surfaces are in parallel and perpendicular to the substrate 32. |
