An optoelectronic device includes an off-cut III-V semiconductor substrate, a set of epitaxial layers formed on the off-cut III-V semiconductor substrate, and a horizontal cavity surface-emitting laser (HCSEL) having a laser resonant cavity formed in the set of epitaxial layers. The same or another optoelectronic device includes a semiconductor substrate; a laser, epitaxially grown on the semiconductor substrate and having a laser resonant cavity; a semiconductor device, epitaxially grown on the semiconductor substrate and separated from the laser by a single trench having a first vertical wall abutting the laser and a second vertical wall abutting the semiconductor device; and at least one coating on at least one of the first vertical wall or the second vertical wall. The laser resonant cavity of the laser has a horizontal portion parallel to the semiconductor substrate, and each of the first vertical wall and the second vertical wall is oriented perpendicular to the semiconductor substrate.

The present invention relates to a microdisk laser having characteristics of unidirectional emission and an ultra-high quality factor and also a microdisk laser composed of four circular arcs and configured to emit light in one direction in a resonance mode having the form of a whispering gallery mode formed by total reflection.

A low power, side-emitting semiconductor laser diode is provided. The laser diode is formed from a semiconductor heterostructure having an active layer sandwiched between an n-type layer and a p-type layer, wherein the active layer forms a gain medium of width W. Front and back reflectors of reflectivity Rf and Rb are arranged on opposing side facets of the semiconductor heterostructure part to form a cavity of length L containing at least a part of the active layer which thus forms the gain medium for the laser diode, the gain medium having an internal loss i. To achieve stable, low power operation close to threshold, the laser diode is configured with the following parameter combination: width W: 1 mW2 m; cavity length L: 100 mL600 m; internal loss i: 0 cm.sup.1i30 cm.sup.1; back reflectivity Rb: 100Rb80%; and front reflectivity Rf: 100Rf60%.

The present invention relates to a microdisk laser having characteristics of unidirectional emission and an ultra-high quality factor and also a microdisk laser composed of four circular arcs and configured to emit light in one direction in a resonance mode having the form of a whispering gallery mode formed by total reflection.

An optical semiconductor device includes: a substrate having a (100) face as a surface; a first protrusion protruding from the substrate in a first direction and including a first mesa having a laminate structure in which a plurality of semiconductor layers are layered on the surface in the first direction, the first mesa including an active layer as one of the semiconductor layers; and a second protrusion protruding from the substrate in the first direction at a position distance from the first protrusion in a second direction intersecting with the first direction, and the second protrusion having a laminate structure in which a plurality of semiconductor layers are layered on the surface in the first direction. An end face in the first direction of the second protrusion has a substantially polygonal shape, and each side of the end face is non-parallel to a virtual line extending in [0-11] direction.

A low power, side-emitting semiconductor laser diode is provided. The laser diode is formed from a semiconductor heterostructure having an active layer sandwiched between an n-type layer and a p-type layer, wherein the active layer forms a gain medium of width W. Front and back reflectors of reflectivity Rf and Rb are arranged on opposing side facets of the semiconductor heterostructure part to form a cavity of length L containing at least a part of the active layer which thus forms the gain medium for the laser diode, the gain medium having an internal loss i. To achieve stable, low power operation close to threshold, the laser diode is configured with the following parameter combination: width W: 1 mW2 m; cavity length L: 100 mL600 m; internal loss i: 0 cm.sup.1i30 cm.sup.1; back reflectivity Rb: 100Rb80%; and front reflectivity Rf: 100Rf60%.

A refractive index of the active layer is obtained by a photoluminescence inspection and an equivalent refractive index of the optical semiconductor element is computed. A refractive index of the optical waveguide layer is obtained by a photoluminescence inspection and an equivalent refractive index of the optical waveguide is computed. A film thickness of the refractive index adjustment layer is adjusted by etching the refractive index adjustment layer so that the equivalent refractive index of the optical semiconductor element and the equivalent refractive index of the optical waveguide are matched to each other. After adjusting the film thickness of the refractive index adjustment layer, a contact layer is formed on the second cladding layer and the refractive index adjustment layer. The optical waveguide is a passive waveguide to which no electrical field is applied and no current is injected.

Method for producing semiconductor laser elements (1) comprises A) providing a carrier composite (20) having a plurality of carriers (2) for the semiconductor laser elements (1), B) providing a laser bar (30) having a plurality of semiconductor laser diodes (3) which comprise a common growth substrate (31) and a semiconductor layer sequence (32) grown thereon, C) generating predetermined breaking points (35) on a substrate underside (34) of the growth substrate (31), said substrate underside facing away from the semiconductor layer sequence (32), D) attaching the laser bar (30) to a carrier upper side (23) of the carrier composite (20), wherein the attachment is performed at an elevated temperature and is followed by cooling, and E) singulating into the semiconductor laser elements (1), wherein steps B) to E) are performed in the indicated sequence.

The present invention provide a laser, where the laser is divided into a laser region and a grating adjustment region through a first electrical isolation layer; the laser region is configured to generate optical signals, where the optical signals include an optical signal with a wavelength corresponding to a 0 signal and an optical signal with a wavelength corresponding to a 1 signal; the grating adjustment region is configured to adjust a wavelength of the grating adjustment region by controlling current of the grating adjustment region, so that the optical signal with the wavelength corresponding to the 1 signal of the laser region passes through the grating adjustment region, and the optical signal with the wavelength corresponding to the 0 signal of the laser region returns to the laser region, thereby implementing suppression to chirp of a directly modulated laser.