Patent attributes
In a semiconductor optical device, the semiconductor substrate has a primary surface intersecting with a predetermined axis. The lower cladding region of the first conductive type is provided on the primary surface thereof. The lower cladding region includes ridge regions and a base region. The base region has first portions and second portions. The first portions and the second portions are alternately arranged along a predetermined plane perpendicular to the predetermined axis. Each first portion extends in an optical propagating direction. Each second portion extends in the optical propagating direction. Each ridge region is located on each second portion. Each ridge region has a side and a top, and each first portion has a top. The upper cladding layer of the second conductive type is provided on the primary surface of the semiconductor substrate. The bulk active layer is provided between the upper cladding layer and the lower cladding region. The bulk active layer includes first portions, second portions and third portions. Each first portion of the bulk active layer is located on each first portion of the base region of the lower cladding region. Each second portion of the bulk active layer is located on the top of each ridge region and each third portion of the bulk active layer is located on the side of the ridge region.