A semiconductor optical element has a mesa structure in which an active layer is embedded, and comprises a straight propagating section and a spot size converter section being such that a light confinement in the active layer is weaker than that of the straight propagating section, wherein in a same plane parallel to a layer surface of the active layer, an average value of a width of the mesa structure of the straight propagating section is smaller than a value of the width of the mesa structure at the emission facet of the spot size converter section, and at a top part of the mesa structure, an electrode is formed so that an electric current is injected in the active layer across the entire length of the straight propagating section and the spot size converter section.

A semiconductor optical amplifier array device includes: a substrate; and a plurality of semiconductor optical amplifiers formed on the substrate, each of the semiconductor optical amplifiers including an active region, and two input-output ports optically connected to the active region and disposed on same facet of the semiconductor optical amplifier array device. The plurality of semiconductor optical amplifiers include a first semiconductor optical amplifier in which length of the active region is equal to a first length, and a second semiconductor optical amplifier in which length of the active region is equal to a second length that is different from the first length.

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.

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.

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.

A semiconductor laser diode includes a semiconductor substrate, a laser portion that is provided on the semiconductor substrate and has an active layer, and an optical modulation portion that is provided on the semiconductor substrate and has a light absorption layer configured to absorb laser light from the laser portion. In the semiconductor laser diode, the light absorption layer includes a first light absorption layer and a second light absorption layer. The active layer, the first light absorption layer, and the second light absorption layer are arranged in this order in a light guiding direction. The first light absorption layer has a first wavelength obtained by photoluminescence measurement, the second light absorption layer has a second wavelength obtained by photoluminescence measurement, and the second wavelength is longer than the first wavelength.

A semiconductor device includes a substrate, a semiconductor laser part formed on the substrate and having an active layer with an uniform composition and a first ridge structure, and an adjacent part formed on the substrate, having a core layer with an uniform composition and a second ridge structure, and being an optical modulator or an optical waveguide which is in contact with the semiconductor laser part, wherein the first ridge structure is largest in width at a first contact part which is in contact with the second ridge structure, and the second ridge structure is largest in width at a second contact part which is in contact with the first ridge structure.

An optical device that includes: a base layer; a first region supported by the base layer, the first region including a first plurality of quantum-confined nanostructures and having a first density of quantum-confined nanostructures; a second region supported by the base layer, the first and second regions being non-overlapping regions, the second region having a second density of quantum-confined nanostructures lower than the first density; and an optical confinement structure supported by the base layer and configured to guide at least one transverse optical mode between a first end and a second end of the optical confinement structure. The first region substantially overlaps with the at least one transverse optical mode, and the first density varies across a cross-section of the optical device.

A hybrid grating comprises a first grating layer composed of a first solid-state material, and a second grating layer over the first grating layer and composed of a second solid-state material, the second solid state-material being different than the first solid-state material and having a monocrystalline structure.

An electrically-operated semiconductor laser device and method for forming the laser device are provided. The laser device includes a fin structure to which a waveguide is optically coupled. The waveguide is optically coupled to passive waveguides at either end thereof. The fin structure includes an array of fin elements, each fin element comprising Group III-V materials.