SEMICONDUCTOR OPTICAL DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a semiconductor optical element having a structure by which an optical field is unevenly distributed to an n-type clad layer side and that is less likely to generate crystal defects.SOLUTION: A mesa stripe structure having a lamination structure obtained by holding an active layer between an n-type clad layer and a p-type clad layer is arranged on a substrate made of InP. A current blocking region is buried on a substrate on both sides of the mesa stripe structure. A pair of electrodes injecting carriers to the active layer are formed. The n-type clad layer includes a high-refractive index layer made of AlGaInAs lattice-matching with the InP substrate or AlInAs lattice-matching with the InP substrate. For one example, the current blocking region includes an n-type InP-based material layer and a p-type InP-based material layer. A vertical relation between the n-type InP-based material layer and the p-type InP-based material layer in the current blocking region is reverse to that between the n-type clad layer and the p-type clad layer of the mesa stripe structure.