A device comprising a semiconductor layer including a plurality of compositional inhomogeneous regions is provided. The difference between an average band gap for the plurality of compositional inhomogeneous regions and an average band gap for a remaining portion of the semiconductor layer can be at least thermal energy. Additionally, a characteristic size of the plurality of compositional inhomogeneous regions can be smaller than an inverse of a dislocation density for the semiconductor layer.

There are included: a substrate; a semiconductor laser part formed on the substrate by stacking a plurality of layers including an active layer; and an adjacent part formed on the substrate by stacking a plurality of layers including a core layer, and being an optical modulator or an optical waveguide in contact with the semiconductor laser part through butt joint joining thereto. In a semiconductor device including the semiconductor laser part and the adjacent part which are joined in a butt joint manner, at least a portion, of the semiconductor laser part, that is contact with the adjacent part is disordered.

A laser chip including a plurality of stripes is disclosed, where a laser stripe can be grown with an initial optical gain profile, and its optical gain profile can be shifted by using an intermixing process. In this manner, multiple laser stripes can be formed on the same laser chip from the same epitaxial wafer, where at least one laser stripe can have an optical gain profile shifted relative to another laser stripe. For example, each laser stripe can have a shifted optical gain profile relative to its neighboring laser stripe, thereby each laser stripe can emit light with a different range of wavelengths. The laser chip can emit light across a wide range of wavelengths. Examples of the disclosure further includes different regions of a given laser stripe having different intermixing amounts.

There are included: a substrate; a semiconductor laser part formed on the substrate by stacking a plurality of layers including an active layer; and an adjacent part formed on the substrate by stacking a plurality of layers including a core layer, and being an optical modulator or an optical waveguide in contact with the semiconductor laser part through butt joint joining thereto. In a semiconductor device including the semiconductor laser part and the adjacent part which are joined in a butt joint manner, at least a portion, of the semiconductor laser part, that is contact with the adjacent part is disordered.

A semiconductor layer structure may include a substrate, a buffer layer formed on the substrate, and a set of epitaxial layers formed on the buffer layer. The buffer layer may have a thickness that is greater than 2 micrometers (m). The set of epitaxial layers may include a quantum well layer. A quantum well intermixing region may be formed in association with the quantum well layer and a material diffused from a region of a surface of the semiconductor layer structure.

A device including one or more layers with lateral regions configured to facilitate the transmission of radiation through the layer and lateral regions configured to facilitate current flow through the layer is provided. The layer can comprise a short period superlattice, which includes barriers alternating with wells. In this case, the barriers can include both transparent regions, which are configured to reduce an amount of radiation that is absorbed in the layer, and higher conductive regions, which are configured to keep the voltage drop across the layer within a desired range.

A device comprising a semiconductor layer including a plurality of compositional inhomogeneous regions is provided. The difference between an average band gap for the plurality of compositional inhomogeneous regions and an average band gap for a remaining portion of the semiconductor layer can be at least thermal energy. Additionally, a characteristic size of the plurality of compositional inhomogeneous regions can be smaller than an inverse of a dislocation density for the semiconductor layer.

A device comprising a semiconductor layer including a plurality of compositional inhomogeneous regions is provided. The difference between an average band gap for the plurality of compositional inhomogeneous regions and an average band gap for a remaining portion of the semiconductor layer can be at least thermal energy. Additionally, a characteristic size of the plurality of compositional inhomogeneous regions can be smaller than an inverse of a dislocation density for the semiconductor layer.

An array of monolithic wavelength division multiplexed (WDM) vertical cavity surface emitting lasers (VCSELs) is provided with quantum well intermixing. Each VCSEL includes a bottom distributed Bragg reflector (DBR), an upper distributed Bragg reflector, and a laser cavity therebetween. The laser cavity includes a multiple quantum well (MQW) layer sandwiched between a lower separate confinement heterostructure (SCH) and an upper SCH layer. Each MQW region experiences a different amount of quantum well intermixing and concomitantly a different lasing wavelength shift.

A device including one or more layers with lateral regions configured to facilitate the transmission of radiation through the layer and lateral regions configured to facilitate current flow through the layer is provided. The layer can comprise a short period superlattice, which includes barriers alternating with wells. In this case, the barriers can include both transparent regions, which are configured to reduce an amount of radiation that is absorbed in the layer, and higher conductive regions, which are configured to keep the voltage drop across the layer within a desired range.