A nitride semiconductor light emitting device includes a first coat film of aluminum nitride or aluminum oxynitride formed at a light emitting portion and a second coat film of aluminum oxide formed on the first coat film. The thickness of the second coat film is at least 80 nm and at most 1000 nm. Here, the thickness of the first coat film is preferably at least 6 nm and at most 200 nm.

A multilayer device includes a substrate and a first layer disposed on the substrate. A trench extends through one or both of the substrate and the first layer. The trench has a first sidewall spaced apart from a second sidewall, each sidewall extending from an upper surface of the substrate to a lower surface of the first layer. An optically active region is disposed on the first layer overlying the trench, such that at least a portion of the optically active region is located within a set of lines corresponding to the sidewalls of the trench.

A nitride semiconductor light emitting device includes a first coat film of aluminum nitride or aluminum oxynitride formed at a light emitting portion and a second coat film of aluminum oxide formed on the first coat film. The thickness of the second coat film is at least 80 nm and at most 1000 nm. Here, the thickness of the first coat film is preferably at least 6 nm and at most 200 nm.

This invention discloses a method for the fabrication of GaN-based vertical cavity surface-emitting devices featuring a silicon-diffusion defined current blocking layer (CBL). Such devices include vertical-cavity surface-emitting laser (VCSEL) and resonant-cavity light-emitting diode (RCLED). The silicon-diffused P-type GaN region can be converted into N-type GaN and thereby attaining a current blocking effect under reverse bias. And the surface of the silicon-diffused area is flat so the thickness of subsequent optical coating is uniform across the emitting aperture. Thus, this method effectively reduces the optical-mode field diameter of the device, significantly decreases the spectral width of LED, and produces single-mode emission of VCSEL

A method for fabricating a laser diode device includes providing a gallium and nitrogen containing substrate member having a surface region, forming a patterned dielectric material overlying the surface region to expose a portion of the surface region within a vicinity of an recessed region of the patterned dielectric material and maintaining an upper portion of the patterned dielectric material overlying covered portions of the surface region, and performing a lateral epitaxial growth overlying the exposed portion of the surface region to fill the recessed region and causing a thickness of the lateral epitaxial growth to be formed overlying the upper portion of the patterned dielectric material. The method also includes forming an n-type gallium and nitrogen containing material, forming an active region, and forming a p-type gallium and nitrogen containing material. The method further includes forming a waveguide structure in the p-type gallium and nitrogen containing material.

A high-quality nitride crystal can be produced efficiently by charging a nitride crystal starting material that contains tertiary particles having a maximum diameter of from 1 to 120 mm and formed through aggregation of secondary particles having a maximum diameter of from 100 to 1000 m, in the starting material charging region of a reactor, followed by crystal growth in the presence of a solvent in a supercritical state and/or a subcritical state in the reactor, wherein the nitride crystal starting material is charged in the starting material charging region in a bulk density of from 0.7 to 4.5 g/cm.sup.3 for the intended crystal growth.

An ultralow defect gallium-containing nitride crystal and methods of making ultralow defect gallium-containing nitride crystals are disclosed. The crystals are useful as substrates for light emitting diodes, laser diodes, transistors, photodetectors, solar cells, and photoelectrochemical water splitting for hydrogen generators.

Core-cladding planar waveguide (PWG) structures and methods of making and using same. The core-cladding PWG structures can be synthesized by hydride vapor phase epitaxy and processed by mechanical and chemical-mechanical polishing. An Er doping concentration of [Er] between 110.sup.18 atoms/cm.sup.3 and 110.sup.22 atoms/cm.sup.3 can be in the core layer. Such PWGs have a core region that can achieve optical confinement between 96% and 99% and above.

A nano Bessel laser beam emitter and a method for manufacturing the same are disclosed. The nano Bessel laser beam emitter includes a first Bragg reflecting layer, a light-emitting layer and a second Bragg reflecting layer, where the first Bragg reflecting layer defines a cylindrical through hole; the light-emitting layer is provided on a surface of the first Bragg reflecting layer and is configured to generate a light beam; and the second Bragg reflecting layer is provided on the light-emitting layer at a side distal to the first Bragg reflecting layer.

The present disclosure falls into the field of optoelectronics, particularly, includes the design, epitaxial growth, fabrication, and characterization of Laser Diodes (LDs) operating in the ultraviolet (UV) to infrared (IR) spectral regime on patterned substrates (PSs) made with (formed on) low cost, large size Si, or GaN on sapphire, GaN, and other wafers. We disclose three types of PSs, which can be universal substrates, allowing any materials (III-Vs, II-VIs, etc.) grown on top of it with low defect and/or dislocation density.