A laser diode includes an active zone that emits radiation in a lateral emission angle range in a plane of the active zone via an emission side of a layer arrangement, an electrical contact is configured on a top side of the layer arrangement, the electrical contact includes a metallic adhesion layer and at least one metallic contact layer, the adhesion layer is arranged on the layer arrangement, the adhesion layer includes a layer stack including a first and a second layer, the first layer is arranged on the layer arrangement, the first layer is configured in a planar fashion, the second layer is subdivided into at least one first and at least one second partial surface, the adhesion layer is arranged in the first partial surface, and the contact layer is arranged on the first partial surface and in the second partial surface.

According to embodiments of the present invention, an optical device is provided. The optical device includes a substrate, a semiconductor layer on the substrate, the semiconductor layer having a beam structure that is subjected to a tensile strain, wherein the beam structure includes a plurality of nanostructures, and wherein, for each nanostructure of the plurality of nanostructures, the nanostructure is configured to locally amplify the tensile strain at the nanostructure to define a strain-induced artificial quantum heterostructure for quantum confinement. According to a further embodiment of the present invention, a method of forming an optical device is also provided.

According to embodiments of the present invention, an optical device is provided. The optical device includes a substrate, a semiconductor layer on the substrate, the semiconductor layer having a beam structure that is subjected to a tensile strain, wherein the beam structure includes a plurality of nanostructures, and wherein, for each nanostructure of the plurality of nanostructures, the nanostructure is configured to locally amplify the tensile strain at the nanostructure to define a strain-induced artificial quantum heterostructure for quantum confinement. According to a further embodiment of the present invention, a method of forming an optical device is also provided.

Disclosed herein is a semiconductor device. The semiconductor device includes a substrate, a first conductive type semiconductor layer disposed over the substrate, an active layer disposed over the first conductive type semiconductor layer, and a second conductive type semiconductor layer disposed over the active layer. The first conductive type semiconductor layer includes a first layer, a second layer and a third layer having different composition ratios of indium (In). The first semiconductor layer is disposed close to the active layer. The second semiconductor layer is disposed under the first semiconductor layer. The third semiconductor layer is disposed under the second semiconductor layer. In content is reduced from the active layer to the third semiconductor layer, and In content of the third semiconductor layer may be 5% or more to 10% or less of that of the active layer.

Disclosed herein is a semiconductor device. The semiconductor device includes a substrate, a first conductive type semiconductor layer disposed over the substrate, an active layer disposed over the first conductive type semiconductor layer, and a second conductive type semiconductor layer disposed over the active layer. The first conductive type semiconductor layer includes a first layer, a second layer and a third layer having different composition ratios of indium (In). The first semiconductor layer is disposed close to the active layer. The second semiconductor layer is disposed under the first semiconductor layer. The third semiconductor layer is disposed under the second semiconductor layer. In content is reduced from the active layer to the third semiconductor layer, and In content of the third semiconductor layer may be 5% or more to 10% or less of that of the active layer.

The invention inter alia relates to radiation emitter (100) comprising an emitter section (120) and an optical pump section (110) that is capable of generating pump radiation (Rp) in order to excite the emitter section (120) to emit single photons (P) or entangled photon pairs. The optical pump section (110) is ring-shaped and the emitter section (120) is located inside the ring-shaped pump section (110).

An optical semiconductor device includes an InP substrate; an active layer disposed above the InP substrate; a n-type semiconductor layer disposed below the active layer; and a p-type clad layer disposed above the active layer, wherein the p-type clad layer includes one or more p-type In.sub.1-xAl.sub.xP layers, the Al composition x of each of the one or more p-type In.sub.1-xAl.sub.xP layers is equal to or greater than a value corresponding to the doping concentration of a p-type dopant, and the absolute value of the average strain amount of the whole of the p-type clad layer is equal to or less than the absolute value of a critical strain amount obtained by Matthews' relational expression, using the entire layer thickness of the whole of the p-type clad layer as a critical layer thickness.

An optical device has a gallium and nitrogen containing substrate including a surface region and a strain control region, the strain control region being configured to maintain a quantum well region within a predetermined strain state. The device also has a plurality of quantum well regions overlying the strain control region.

An edge-emitting semiconductor laser and a method for operating a semiconductor laser are disclosed. The edge-emitting semiconductor laser includes an active zone within a semiconductor layer sequence and a stress layer. The active zone is configured for being energized only in a longitudinal strip perpendicular to a growth direction of the semiconductor layer sequence. The semiconductor layer sequence has a constant thickness throughout in the region of the longitudinal strip so that the semiconductor laser is gain-guided. The stress layer may locally stress the semiconductor layer sequence in a direction perpendicular to the longitudinal strip and in a direction perpendicular to the growth direction. A refractive index of the semiconductor layer sequence, in regions which, seen in plan view, are located next to the longitudinal strip, for the laser radiation generated during operation is reduced by at least 210.sup.4 and by at most 510.sup.3.

Disclosed is an optically pumped vertical cavity laser structure operating in the mid-infrared region, which has demonstrated room-temperature continuous wave operation. This structure uses a periodic gain active region with type I quantum wells comprised of InGaAsSb, and barrier/cladding regions which provide strong hole confinement and substantial pump absorption. A preferred embodiment includes at least one wafer bonded GaAs-based mirror. Several preferred embodiments also include means for wavelength tuning of mid-IR VCLs as disclosed, including a MEMS-tuning element. This document also includes systems for optical spectroscopy using the VCL as disclosed, including systems for detection concentrations of industrial and environmentally important gases.