A multi-wavelength light-emitting semiconductor device and a method of fabricating the same are disclosed. The semiconductor device includes a substrate, a first reflector on the substrate, a light emission layer on the first reflector, second reflectors on corresponding active regions; and apertures on corresponding active regions. The light emission layer includes active regions. Each of the active regions includes a primary emission wavelength different from each other.

A vertical-cavity surface-emitting laser (VCSEL) may include a substrate. The VCSEL may include a bottom mirror structure over the substrate. The VCSEL may include a first dilute nitride active region over the bottom mirror structure. The VCSEL may include a tunnel junction over the first dilute nitride active region. The VCSEL may include a second dilute nitride active region over the tunnel junction. The VCSEL may include a top mirror structure over the second dilute nitride active region.

Provided is a semiconductor epitaxial wafer, including a substrate, a first epitaxial structure, a first ohmic contact layer and a second epitaxial stack structure. It is characterized in that the ohmic contact layer includes a compound with low nitrogen content, and the ohmic contact layer does not induce significant stress during the crystal growth process. Accordingly, the second epitaxial stack structure formed on the ohmic contact layer can have good epitaxial quality, thereby providing a high-quality semiconductor epitaxial wafer for fabricating a GaAs integrated circuit or a InP integrated circuit. At the same time, the ohmic contact properties of ohmic contact layers are not affected, and the reactants generated during each dry etching process are reduced.

Stacked edge-emitting lasers having multiple active regions coupled together using tunnel junctions. The composition of each of the active regions (quantum wells and/or barriers) differs to provide a controlled different emission wavelength for each junction, when each junction is individually operated at the same fixed temperature. When the device is under operation, a thermal gradient exists across the junctions, and the emission wavelengths of each junction coincide as the different temperature for each junction causes relative wavelength shifts. Thus, the effect of temperature on the emission wavelength of the device is compensated for, producing a narrower linewidth emission.

A semiconductor device includes a semiconductor layer formed of a III-V group semiconductor crystal containing As as a primary component of a V group. A V group element other than As has been introduced at a concentration of 0.02 to 5% into a V group site of the III-V group semiconductor crystal in the semiconductor layer.

In some implementations, a method may include forming a quantum well (QW) layer using an epitaxial growth process, where the epitaxial growth process is performed according to a first growth mode to form the QW layer. The method may include forming a quantum well barrier (QWB) layer using the epitaxial growth process, where the epitaxial growth process is performed according to a second growth mode to form the QWB layer. In some implementations, a nitrogen flux used in the first growth mode is different from a nitrogen flux used in the second growth mode. In some implementations, a gallium flux used in the first growth mode is different from a gallium flux used in the second growth mode.