US Patent 7508049 Semiconductor optical device

A semiconductor optical device comprises a first conductive type III-V compound semiconductor layer, a second conductive type III-V compound semiconductor layer, and an active region. The first conductive type III-V compound semiconductor layer is provided on a substrate. The second conductive type III-V compound semiconductor layer is provided on the substrate. The active region is provided between the first conductive type III-V compound semiconductor layer and the second conductive type III-V compound semiconductor layer. The active region includes a III-V compound semiconductor layer. The III-V compound semiconductor layer contains nitrogen and arsenic as V-group element. The hydrogen concentration of the III-V compound semiconductor layer is greater than 6×1016 cm−3. The III-V compound semiconductor layer of the active region is doped with n-type dopant.