The present invention relates to a device for generating laser radiation.

An object of the present invention is to indicate a laser diode which simultaneously has a high degree of efficiency and a low degree of far field divergence.

The diode laser according to the invention comprises a current barrier (5), characterized in that the current barrier (5) extends along a third axis (X), wherein the current barrier (5) has at least one opening, and a first width (W1) of the opening of the current barrier (5) along the third axis (X) is smaller than a second width (W2) of the metal p-contact (8) along the third axis (X).

In an embodiment, an edge-emitting semiconductor laser diode includes a growth substrate, a semiconductor layer sequence located on the growth substrate, the semiconductor layer sequence having an active layer and an etch stop layer and two facets located opposite each other, wherein the facets bound the semiconductor layer sequence in a lateral direction, wherein the semiconductor layer sequence includes two edge regions adjoining the facets and a central region directly adjoining both edge regions, wherein, within each of the edge regions, a volume fraction of the active layer in the semiconductor layer sequence is smaller than in the central region, wherein the active layer is spaced apart from one facet, wherein a distance of the active layer to the facet varies along a direction parallel to this facet, and wherein the etch stop layer is arranged between the growth substrate and the active layer.

A quantum cascade semiconductor laser includes a laser structure having a first area including an end face, a second area, and a third area; a metal layer provided on a major surface in the third area; a separation area provided on the major surface; and a reflector provided on the laser structure. The reflector includes a dielectric film and a metal reflecting film provided on the end face and the separation area. The separation area has a first portion, a second portion, and a third portion. The metal layer has an edge separated from the end face in the third area. The contact layer has an edge separated from the end face in the third area. The first portion projects more than the second portion over the semiconductor mesa. The third portion projects more than the second portion over the semiconductor mesa.

The present technology can be used to control the current injection profile in the longitudinal direction of a high-power diode laser in order to optimize current densities as a function of position in the cavity to promote higher reliable output power and increase the electrical to optical conversion efficiency of the device beyond the level which can be achieved without application of this technique. This approach can be utilized, e.g., in the fabrication of semiconductor laser chips to improve the output power and wall plug efficiency for applications requiring improved performance operation.

A semiconductor device includes a first pair of nitride semiconductor regions, and a current confinement region which includes a first portion, a second portion disposed on a side of the first portion, and a third portion disposed on another side of the first portion. A width of the second portion is larger than a width of the first portion, the width of the second portion is larger than a width between the first pair of nitride semiconductor regions, and both ends of the second portion are covered by the first pair of nitride semiconductor regions, respectively.

A laser diode includes a substrate, an epitaxial structure, an electrode contacting layer and an optical cladding layer. The epitaxial structure is disposed on the substrate, and is formed with a ridge structure opposite to the substrate. The electrode contacting layer is disposed on a top surface of the ridge structure. The optical cladding layer has a refractive index smaller than that of the electrode contacting layer The optical cladding layer includes a first cladding portion which covers side walls of the ridge structure, and a second cladding portion which is disposed on a portion of the top surface of the ridge structure. A method for manufacturing the abovementioned laser diode is also disclosed.

A semiconductor optical amplifier includes: a substrate; a light source unit formed on the substrate; and an optical amplification part that amplifies light propagating in a predetermined direction from the light source unit and emits the amplified light in an emission direction intersecting with the substrate surface. The optical amplification part includes a conductive region extending in the predetermined direction along the substrate surface from the light source unit, and a nonconductive region formed around the conductive region. The conductive region includes a first region extending from the light source unit and having a predetermined width as seen from a direction perpendicular to the substrate surface, and a second region connected to the first region and having a width widened relative to the predetermined width of the first region, the second region being configured to expand the propagation light in a direction intersecting with the predetermined direction.

The disclosure relates to a semiconductor laser includes a semiconductor layer sequence with an-n-type n-region, a p-type p-region and an active zone lying between the two for the purpose of generating laser radiation. A p-contact layer that is permeable to the laser radiation and consists of a transparent conductive oxide is located directly on the p-region for the purpose of current input. An electrically-conductive metallic p-contact structure is applied directly to the p-contact layer. The p-contact layer is one part of a cover layer, and therefore the laser radiation penetrates as intended into the p-contact layer during operation of the semiconductor laser. Two facets of the semiconductor layer sequence form resonator end surfaces for the laser radiation.

A semiconductor laser (2) includes an n-type semiconductor substrate (1), a stack of an n-type cladding layer (4), an active layer (5), and a p-type cladding layer (6) successively stacked on the n-type semiconductor substrate (1). An optical waveguide (3) includes a non-impurity-doped core layer (9) provided on a light output side of the semiconductor laser (2) on the n-type semiconductor substrate (1) and having a larger forbidden band width than the active layer (5), and a cladding layer (10) provided on the core layer (9) and having a lower carrier concentration than the p-type cladding layer (6). The semiconductor laser (2) includes a carrier injection region (X1), and a non-carrier-injection region (X2) provided between the carrier injection region (X1) and the optical waveguide (3).

A semiconductor laser element includes: a substrate; a first-conductivity-type semiconductor layer formed on the substrate; a light-emitting layer formed on the first-conductivity-type semiconductor layer; a second-conductivity-type semiconductor layer that is formed on the light-emitting layer and includes a protrusion in a strip form; a transparent conductive layer formed on the protrusion of the second-conductivity-type semiconductor layer; a protective layer that is formed on the transparent conductive layer and has conductivity; a dielectric film that covers side surfaces of the protrusion of the second-conductivity-type semiconductor layer, side surfaces of the transparent conductive layer, and side surfaces of the protective layer; and an upper electrode formed on the protective layer. The whole of an upper surface of the transparent conductive layer is covered by the protective layer, and part of an upper surface of the protective layer is covered by the dielectric film.