Patent attributes
An apparatus is configured to operate in a single fundamental transverse mode and the apparatus includes a waveguide layer between an n-doped cladding layer and a p-doped cladding layer. The waveguide layer includes a first waveguide part, and an active layer located between the first waveguide part and the p-doped cladding layer, the active layer being asymmetrically within the waveguide layer closer to the p-doped cladding layer than the n-doped cladding layer. The refractive index of the n-doped cladding layer being equal to or larger than the p-doped cladding layer. A first end of the first waveguide part is adjacent to the n-doped cladding layer. A second end of the first waveguide part is adjacent to a first end of the active layer. A desired donor density is doped in the first waveguide part for controlling the carrier density dependent internal optical loss in the first waveguide part at high injection levels.
