A first burying layer burying a side of a first ridge structure is formed by selective growth using a first selective growth mask and a third selective growth mask. The first burying layer is formed by regrowth from a surface of a second semiconductor layer on a side of the first ridge structure. At the same time, by selective growth using a second selective growth mask and a fourth selective growth mask, a second burying layer burying a side of a second ridge structure is formed. The second burying layer is formed by regrowth from a surface of a fourth semiconductor layer on a side of the second ridge structure.

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 1×10.sup.18 atoms/cm.sup.3 and 1×10.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.

High bandwidth (e.g., > 100 GHz) modulators and methods of fabricating such are provided. An EAM comprises a waveguide mesa comprising a continuous multi-quantum well (MQW) layer; a plurality of electrode segments disposed on the waveguide mesa; and a microstrip transmission line disposed on an insulating material layer and in electrical communication with the plurality of electrode segments via conducting bridges. The waveguide mesa comprises alternating active sections and passive sections. An electrode segment of the plurality of electrodes is disposed on a respective one of the active sections. Portions of the continuous MQW layer disposed in each of the active sections having an energy gap defining an active energy gap value. Portions of the continuous MQW layer disposed in each of the passive sections having an energy gap defining an passive energy gap value. The active energy gap value is less than the passive energy gap value.

A light-emitting device includes a laminate provided at a substrate, a first electrode provided on an opposite side of the laminate from the substrate, and a second electrode provided on an opposite side of the first electrode from the substrate. The laminate includes a first semiconductor layer of a first conductivity type, a second semiconductor layer of a second conductivity type different from the first conductivity type, and a light-emitting layer provided between the first semiconductor layer and the second semiconductor layer. The first semiconductor layer is provided between the substrate and the light-emitting layer. The first electrode constitutes a plurality of column portions. The second electrode is coupled to the plurality of column portions. The first electrode is a transparent electrode formed of a metal oxide transmitting light generated at the light-emitting 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.

A semiconductor optical device includes an active layer, the active layer including a plurality of quantum well layers having gain peak wavelengths different from one another in a layering direction thereof, and a plurality of barrier layers, wherein the quantum well layers and the barrier layers are alternately layered over each other, and an n-type dopant has been added in the plurality of quantum well layers having gain peak wavelengths different from one another and in the plurality of barrier layers.

A light-emitting semiconductor chip (100) is provided, having a first semiconductor layer (1), which is at least part of an active layer provided for generating light and which has a lateral variation of a material composition along at least one direction of extent. Additionally provided is a method for producing a semiconductor chip (100).

A method for producing a semiconductor chip (100) is provided, in which, during a growth process for growing a first semiconductor layer (1), an inhomogeneous lateral temperature distribution is created along at least one direction of extent of the growing first semiconductor layer (1), such that a lateral variation of a material composition of the first semiconductor layer (1) is produced. A semiconductor chip (100) is additionally provided.

A device including a non-polarization material includes a number of layers. A first layer of silicon (100) defines a U-shaped groove having a bottom portion (100) and silicon sidewalls (111) at an angle to the bottom portion (100). A second layer of a patterned dielectric on top of the silicon (100) defines vertical sidewalls of the U-shaped groove. A third layer of a buffer covers the first layer and the second layer. A fourth layer of gallium nitride is deposited on the buffer within the U-shaped groove, the fourth layer including cubic gallium nitride (c-GaN) formed at merged growth fronts of hexagonal gallium nitride (h-GaN) that extend from the silicon sidewalls (111), wherein a deposition thickness (h) of the gallium nitride above the first layer of silicon (100) is such that the c-GaN completely covers the h-GaN between the vertical sidewalls.

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 μm, 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.