| 摘要 |
PURPOSE:To suppress diffusion of impurity in an active layer even when a clad layer is doped in a high concentration by providing a low concentration doping region of the side near the active layer and a high concentration doping region of the farther side at both or one of a first conductivity type clad layer and a second conductivity type clad layer. CONSTITUTION:Upper and lower clad layers for holding an active layer 14 are formed of clad layers 13, 15 low concentration doped at the side near the layer 14, and clad layers 12, 16 high concentration doped at the side farther from the layer 14. The layers 12, 16 are high impurity concentrations, but since the layers 13, 15 low concentration doped exist to the layer 14, a decrease in quality of the layer 14 due to impurity diffusion does not occur. The layers 12, 16 occupy most of the n-type clad layer and the p-type clad layer to improve carrier confining effect of the clad layer and to realize a decrease in the resistance of the clad layer. |
