An aspect of the present disclosure includes a direct modulated laser (DML) with a dielectric current confinement ridge waveguide (RWG) structure. The DML comprises a substrate, one or more layers of material disposed on the substrate to provide a multi quantum well (MQW), first and second insulation/dielectric structures disposed on opposite sides of the MQW, and one or more layers of material disposed on the MQW to provide a mesa structure for receiving a driving current. The mesa structure is preferably disposed between the first and second insulation structures to provide a dielectric current confinement (RWG) structure. The mesa structure further preferably includes an overall width that is greater than the overall width than the active region of the DML that provides the MQW.

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 light emitting element according to the present disclosure includes a first light reflecting layer 41, a laminated structure 20, and a second light reflecting layer 42 laminated to each other. The laminated structure 20 includes a first compound semiconductor layer 21, a light emitting layer 23, and a second compound semiconductor layer 22 laminated to each other from a side of the first light reflecting layer. Light from the laminated structure 20 is emitted to an outside via the first light reflecting layer 41 or the second light reflecting layer 42. The first light reflecting layer 41 has a structure in which at least two types of thin films 41A and 41B are alternately laminated to each other in plural numbers. A film thickness modulating layer 80 is provided between the laminated structure 20 and the first light reflecting layer 41.

A light emitting device, includes a selective growth mask layer 44; a first light reflection layer 41 thinner than the selective growth mask layer 44; a laminated structure including a first compound semiconductor layer 21, an active layer 23, and a second compound semiconductor layer 22, the first compound semiconductor layer 21 being formed on the first light reflection layer 41; and a second electrode 32 formed on the second compound semiconductor layer 22, and a second light reflection layer 42, in which the second light reflection layer 42 is opposed to the first light reflection layer 41, and the second light reflection layer is not formed on an upper side of the selective growth mask layer 44.

In a manufacturing method of a semiconductor element of the present disclosure, a first semiconductor part (SL1) includes a protruding portion (TS) protruding toward an underlying substrate (UK), the protruding portion contains a nitride semiconductor, the protruding portion and the underlying substrate are bonded to each other, a semiconductor substrate (HK) includes a hollow portion (TK) located between the underlying substrate and the first semiconductor part, the hollow portion is in contact with a side surface of the protruding portion and communicates with the outside of the semiconductor substrate, and the protruding portion (TS) is irradiated with the laser beam (LZ) before the first semiconductor part is separated from the semiconductor substrate.

A nonpolar III-nitride film grown on a miscut angle of a substrate. The miscut angle towards the <000-1> direction is 0.75° or greater miscut and less than 27° miscut towards the <000-1> direction. Surface undulations are suppressed and may comprise faceted pyramids. A device fabricated using the film is also disclosed. A nonpolar III-nitride film having a smooth surface morphology fabricated using a method comprising selecting a miscut angle of a substrate upon which the nonpolar III-nitride films are grown in order to suppress surface undulations of the nonpolar III-nitride films. A nonpolar III-nitride-based device grown on a film having a smooth surface morphology grown on a miscut angle of a substrate which the nonpolar III-nitride films are grown. The miscut angle may also be selected to achieve long wavelength light emission from the nonpolar film.

A nitride semiconductor free-standing substrate includes a diameter of not less than 40 mm, a thickness of not less than 100 μm, a dislocation density of not more than 5×10.sup.6/cm.sup.2, an impurity concentration of not more than 4×10.sup.19/cm.sup.3, and a nanoindentation hardness of not less than 19.0 GPa at a maximum load in a range of not less than 1 mN and not more than 50 mN.

A method of forming a laser involves forming, on a substrate, a first epitaxial part of the laser that includes at least an active region layer surrounded by first and second waveguide layers. A dielectric layer is formed over the first epitaxial part. Two or more mask openings are patterned within the dielectric layer. The mask openings extend normal to a light-propagation direction of the laser and are spaced apart in the light-propagation direction of the laser. A second epitaxial part of the laser is formed in the mask openings using selective area epitaxy. The second epitaxial part includes a refractive grating with three-dimensional grating features.

The invention relates to a semiconductor laser comprising a layer structure comprising an active zone, wherein the active zone is configured to generate an electromagnetic radiation, wherein the layer structure comprises a sequence of layers, wherein two opposite end faces are provided in a Z-direction, wherein at least one end face is configured to at least partly couple out the electromagnetic radiation, and wherein the second end face is configured to at least partly reflect the electromagnetic radiation, wherein guide means are provided for forming an optical mode in a mode space between the end faces, wherein means are provided which hinder a formation of an optical mode outside the mode space, in particular modes comprising a propagation direction which do not extend perpendicularly to the end faces.

A method for obtaining a smooth surface of an epi-layer with epitaxial lateral overgrowth. The method does not use mis-cut orientations and does not suppress the occurrence of pyramidal hillocks, but instead embeds the pyramidal hillocks in the epi-layer. A growth restrict mask is used to limit the expansion of the pyramidal hillocks in a lateral direction. The surface of the epi-layer becomes extremely smooth due to the disappearance of the pyramidal hillocks.