The light-emitting element of an embodiment outputs a clear optical image while suppressing light output efficiency reduction, and includes a substrate, a light-emitting unit, and a bonding layer. The light-emitting unit has a semiconductor stack, including a phase modulation layer, between first and second electrodes. The phase modulation layer has a base layer and modified refractive index regions, and includes a first region having a size including the second electrode, and a second region. Each gravity center of the second region's modified refractive index region is arranged by an array condition. The light from the stack is a single beam, and regarding a first distance from the substrate to the stack's front surface and a second distance from the substrate to the stack's back surface, a variation amount of the first distance along a direction on the substrate is smaller than a variation amount of the second distance.

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 light emitting device includes a substrate, a laminated structure which is provided to the substrate, and includes a light emitting layer, a first electrode which has contact with the laminated structure at an opposite side of the laminated structure to the substrate, and is configured to inject an electrical current into the light emitting layer, and a wiring layer which is electrically coupled to the first electrode, and has a light shielding property with respect to light generated in the light emitting layer, wherein the wiring layer is provided with a first opening part which the light emitted from the laminated structure passes through, and the first opening part is located inside an outer edge of the first electrode in a plan view.

A light emitting device includes a laminated structure having a plurality of columnar parts, wherein the columnar part includes a first semiconductor layer, a second semiconductor layer different in conductivity type from the first semiconductor layer, and a third semiconductor layer disposed between the first semiconductor layer and the second semiconductor layer, the third semiconductor layer includes a light emitting layer, and the second semiconductor layer includes a first portion, and a second portion which surrounds the first portion in a plan view from a laminating direction of the first semiconductor layer and the light emitting layer, and is lower in impurity concentration than the first portion.

A semiconductor laser element includes: an n-side semiconductor layer formed of a nitride semiconductor; an active layer disposed on or above the n-side semiconductor layer and formed of a nitride semiconductor; a p-side semiconductor layer disposed on the active layer, formed of a nitride semiconductor, and including: an undoped first part disposed in contact with an upper face of the active layer and comprising at least one semiconductor layer, an electron barrier layer disposed in contact with an upper face of the first part, containing a p-type impurity, and having a band gap energy that is larger than a band gap energy of the first part, and a second part disposed in contact with the upper face of the electron barrier layer and comprising at least one p-type semiconductor layer containing a p-type impurity; and a p-electrode disposed in contact with the upper face of the second part.

A method for the reuse of gallium nitride (GaN) epitaxial substrates uses band-gap-selective photoelectrochemical (PEC) etching to remove one or more epitaxial layers from bulk or free-standing GaN substrates without damaging the substrate, allowing the substrate to be reused for further growth of additional epitaxial layers. The method facilitates a significant cost reduction in device production by permitting the reuse of expensive bulk or free-standing GaN substrates.

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.

The present invention proposes an O-band silicon-based high-speed semiconductor laser diode for optical communication and its manufacturing method, by using different buffer layers to form the growth surface of InP material with low dislocation density; N—InAlGaAs is used instead of conventional N—InAlAs electron-blocking layer in the epi-structure to reduce the barrier for electrons to enter the quantum wells from N-type and lower the threshold; a superlattice structure quantum barrier is used instead of a single layer barrier structure to improve the transport of heavy holes in the quantum wells; and the material structure is adjusted to achieve a reliable O-band high direct modulation speed semiconductor laser diode for optical communication on silicon substrate.

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.

A vertical cavity surface emitting device includes a substrate, a first multilayer film reflecting mirror on the substrate, a first semiconductor layer on the first multilayer film reflecting mirror, a light-emitting layer on the first semiconductor layer, and a second semiconductor layer on the light-emitting layer. The second semiconductor layer includes a low resistance region and a high resistance region on an upper surface. The high resistance region is depressed from the low resistance region toward the light-emitting layer outside the low resistance region and impurities of the second conductivity type are inactivated in the high resistance region such that the high resistance region has an electrical resistance higher than an electrical resistance of the low resistance region. A light-transmitting electrode layer is in contact with the low resistance region and the high resistance region, and a second multilayer film reflecting mirror is on the light-transmitting electrode layer.