A semiconductor laser device includes an N-type cladding layer, an active layer, and a P-type cladding layer. The active layer includes a well layer, a P-side first barrier layer above the well layer, and a P-side second barrier layer above the P-side first barrier layer. The P-side second barrier layer has an AI composition ratio higher than an AI composition ratio of the P-side first barrier layer. The P-side second barrier layer has band gap energy greater than band gap energy of the P-side first barrier layer. The semiconductor laser device has an end face window structure in which band gap energy of a portion of the well layer in a vicinity of an end face that emits the laser light is greater than band gap energy of a central portion of the well layer in a resonator length direction.

A semiconductor component for emitting light includes a main body that comprises at least one mesa body. The mesa body has an emission region for emitting the light. The emission region is assigned a first mirror portion, a second mirror portion, and an active portion arranged between the two mirror portions and serving to produce the light. The semiconductor component further includes electrical contacts for feeding electrical energy into the active portion, with at least one stress element that is attached to a surface of the main body. The stress element is configured to generate in the main body a material stress which has an effect on one or more polarization properties of the emitted light.

[Object] To provide a laser element capable of preventing laser characteristics from deteriorating while suppressing electron overflow and improving the yield at the time of production.

[Solving Means] A laser element according to the present technology includes: a first semiconductor layer; a second semiconductor layer; an active layer; and an electron barrier layer. The first semiconductor layer is formed of a group iii nitride semiconductor having a first conducive type. The second semiconductor layer is formed of a group iii nitride semiconductor having a second conductive type. The active layer is formed of a group iii nitride semiconductor and is provided between the first semiconductor layer and the second semiconductor layer. The electron barrier layer is provided between the active layer and the second semiconductor layer and is formed of a group iii nitride semiconductor having a composition ratio of Al larger than that of the second semiconductor layer, a recessed and projecting shape being formed on a surface of the electron barrier layer on a side of the second semiconductor layer, the recessed and projecting shape having a height difference between a projecting portion and a recessed portion in a direction perpendicular to a layer surface direction being 2 nm or more and less than 10 nm.

A laser diode (1) includes an AlN single crystal substrate (11), an n-type cladding layer (12) formed on the substrate and including a nitride semiconductor layer having n-type conductivity, a light-emitting layer (14) formed on the n-type cladding layer and including one or more quantum wells, a p-type cladding layer (20) formed on the light-emitting layer and including a nitride semiconductor layer having p-type conductivity, and a p-type contact layer (18) formed on the p-type cladding layer and including a nitride semiconductor that includes GaN. The p-type cladding layer includes a p-type longitudinal conduction layer (16) that includes Al.sub.sGa.sub.1−sN (0.3≤s≤1), has a composition gradient such that the Al composition s decreases with increased distance from the substrate, and has a film thickness of less than 0.5 μm, and a p-type transverse conduction layer (17) that includes Al.sub.tGa.sub.1−tN (0<t≤1).

A semiconductor device includes a substrate comprising a layer made of Ge and a semiconductor multilayer structure grown on the layer made of Ge. The semiconductor multilayer structure includes at least one first layer comprising a material selected from a group consisting of Al.sub.xGa.sub.1-xAs, Al.sub.xGa.sub.1-x-yIn.sub.yAs, Al.sub.xGa.sub.1-x-yIn.sub.yAs.sub.1-zP.sub.z, Al.sub.xGa.sub.1-x-yIn.sub.yAs.sub.1-zN.sub.z, and Al.sub.xGa.sub.1-x-yIn.sub.yAs.sub.1-z-cN.sub.zP.sub.c, Al.sub.xGa.sub.1-x-yIn.sub.yAs.sub.1-z-cN.sub.zSb.sub.c, and Al.sub.xGa.sub.1-x-yIn.sub.yAs.sub.1-z-cP.sub.zSb.sub.c, wherein for any material a sum of the contents of all group-III elements equals 1 and a sum of the contents of all group-V elements equals 1. The semiconductor multilayer structure also includes at least one second layer comprising a material selected from a group consisting of GaInAsNSb, GaInAsN, AlGaInAsNSb, AlGaInAsN, GaAs, GaInAs, GaInAsSb, GaInNSb, GaInP, GaInPNSb, GaInPSb, GaInPN, AlInP, AlInPNSb, AlInPN, AlInPSb, AlGaInP, AlGaInPNSb, AlGaInPN, AlGaInPSb, GaInAsP, GaInAsPNSb, GaInAsPN, GaInAsPSb, GaAsP, GaAsPNSb, GaAsPN, GaAsPSb, AlGaInAs and AlGaAs.

An edge-emitting semiconductor laser and a method for operating a semiconductor laser are disclosed. In an embodiment, 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 2×10.sup.−4 and by at most 5×10.sup.−3.

Methods are provided for modifying the emission wavelength of a semiconductor quantum well laser diode, e.g. by blue shifting the emission wavelength. The methods can be applied to a variety of semiconductor quantum well laser diodes, e.g. group III-V semiconductor quantum wells. The group III-V semiconductor can include AlSb, AlAs, Aln, AlP, BN, GaSb, GaAs, GaN, GaP, InSb, InAs, InN, and InP, and group III-V ternary semiconductors alloys such as Al.sub.xGa.sub.i.xAs. The methods can results in a blue shifting of about 20 meV to 350 meV, which can be used for example to make group III-V semiconductor quantum well laser diodes with an emission that is orange or yellow. Methods of making semiconductor quantum well laser diodes and semiconductor quantum well laser diodes made therefrom are also provided.

A vertical external-cavity surface-emitting laser (VECSEL) whose blueshift is reduced also in a high intensity range of emitted laser light is realized. A surface-emitting device for VECSEL includes a base substrate made of GaN and c-axis oriented, and an emitter structure formed of a group 13 nitride semiconductor and provided on the base substrate. The emitter structure is formed of unit deposition parts, each of which is provided on the base substrate and includes a DBR layer having a distributed Bragg reflection structure and an active layer that has a multiple quantum well structure and generates excitation emission in response to irradiation with external laser light. A c-axis orientation of each of the unit deposition parts conforms to the c-axis orientation of the base substrate located directly below the unit deposition parts. Grooves are formed between the unit deposition parts.

An n-side composition gradient layer includes an intermediate layer and composition continuous gradient layers. The intermediate layer is the group III nitride semiconductor layer containing In. The composition continuous gradient layers are group III nitride semiconductor layers in which an In composition changes in a direction perpendicular to a boundary surface between a well layer and a barrier layer. A thickness of the intermediate layer is thinner than a thickness of the well layer. An In composition of the intermediate layer is equal to or less than an In composition of the well layer. In the composition continuous gradient layers, the In composition continuously changes in a streamline manner toward the intermediate layer.

A semiconductor laser may include a substrate, an active region, and an electron stopper layer. The electron stopper layer may include an aluminum gallium indium arsenide phosphide alloy. The aluminum gallium indium arsenide phosphide alloy may have an Al.sub.xGa.sub.yIn.sub.(1-x-y)As.sub.zP.sub.(1-z) composition.