Disclosed is an epitaxial substrate with a 2D material interposer on a surface of a polycrystalline substrate. The ultra-thin 2D material interposer is grown by van der Waals epitaxy. The lattice constant of a surface layer of the ultra-thin 2D material interposer and the coefficient of thermal expansion of the substrate base are highly fit with those of AlGaN or GaN. The ultra-thin 2D material interposer is of a single-layer structure or a composite-layer structure. An AlGaN or GaN single crystalline epitaxial layer is grown on the ultra-thin 2D material interposer by virtue of the van der Waals epitaxy. Therefore, the large-size substrate may be manufactured with far lower costs than related single crystal wafers.

A communication module includes a laser driving unit (LDU) and one or more multifunction illumination units. The one or more multifunction illumination units are be coupled to the LDU with an electrical connection and configured to transmit both electrical power and data.

Provided is a nitride semiconductor laser element which includes: a stacked structure including a plurality of semiconductor layers including a light emitting layer, the stacked structure including a pair of resonator end faces located on opposite ends; and a protective film including a dielectric body and disposed on at least one of the pair of resonator end faces. The protective film includes a first protective film (a first emission surface protective film), a second protective film (a second emission surface protective film), and a third protective film (a third emission surface protective film) disposed in stated order above the stacked structure. The first protective film is amorphous, the second protective film is crystalline, and the third protective film is amorphous.

In various embodiments, controlled heating and/or cooling conditions are utilized during the fabrication of aluminum nitride single crystals and aluminum nitride bulk polycrystalline ceramics. Thermal treatments may also be utilized to control properties of aluminum nitride crystals after fabrication.

A method for manufacturing a light emitting element according to the present disclosure is a method for manufacturing a light emitting element which includes a stacked structure 20 in which a first compound semiconductor layer 21, an active layer 23, and a second compound semiconductor layer 22 are stacked, a first light reflecting layer 41, and a second light reflecting layer 42 having a flat shape, and in which a base surface 90 positioned on a first surface side of the first compound semiconductor layer 21 has a protrusion 91 protruding in a direction away from the active layer 23, and a cross-sectional shape of the protrusion 91 includes a smooth curve, the method including: forming a first sacrificial layer 81 on the base surface on which the protrusion 91 is to be formed; forming a second sacrificial layer 82 on the entire surface; and performing etching back from the base surface 91 inward by using the second sacrificial layer 82 and the first sacrificial layer 81 as etching masks.

A vertical cavity light-emitting element includes a substrate, a first multilayer reflector, a semiconductor structure layer, an electrode layer, and a second multilayer reflector. The semiconductor structure layer includes a first semiconductor layer of a first conductivity type on the first multilayer reflector, a light-emitting layer on the first semiconductor layer, and a second semiconductor layer of a second conductivity type on the light-emitting layer. The electrode layer is on an upper surface of the semiconductor structure layer and is electrically in contact with the second semiconductor layer in one region of the upper surface. The second multilayer reflector covers the one region on the electrode layer and constitutes a resonator with the first multilayer reflector. The semiconductor structure layer has one recessed structure including one or a plurality of recessed portions passing through the light-emitting from the upper surface in a region surrounding the one region.

A method and device for emitting electromagnetic radiation at high power using nonpolar or semipolar gallium containing substrates such as GaN, AlN, InN, InGaN, AlGaN, and AlInGaN, is provided. In various embodiments, the laser device includes plural laser emitters emitting green or blue laser light, integrated a substrate.

A semiconductor laser element includes: a first nitride semiconductor layer of a first conductivity-type; a second nitride semiconductor layer of a second conductivity-type; and an active region disposed between the first nitride semiconductor layer and the second nitride semiconductor layer, the active region having a single quantum well structure. The active region comprises a first barrier layer, an intermediate layer, a well layer, and a second barrier layer, in this order in a direction from the first nitride semiconductor layer toward the second nitride semiconductor layer. The well layer is composed of InGaN. The second barrier layer is undoped. A lattice constant of the intermediate layer is greater than a lattice constant of each of the first barrier layer and the second barrier layer, and smaller than a lattice constant of the well layer. A thickness of the intermediate layer is greater than a thickness of the well layer.

A light emitting element includes: a laminated structure 20 obtained by laminating a first compound semiconductor layer 21, an active layer 23, and a second compound semiconductor layer 22; a first light reflecting layer 41 disposed on a first surface side of the first compound semiconductor layer 21; a second light reflecting layer 42 disposed on a second surface side of the second compound semiconductor layer 22; and light convergence/divergence changing means 50. The first light reflecting layer 41 is formed on a concave mirror portion 43. The second light reflecting layer 42 has a flat shape. When light generated in the active layer 23 is emitted to the outside, a light convergence/divergence state before the light is incident on the light convergence/divergence changing means 50 is different from a light convergence/divergence state after the light passes through the light convergence/divergence changing means 50.

A method for growth and fabrication of semipolar (Ga,Al,In,B)N thin films, heterostructures, and devices, comprising identifying desired material properties for a particular device application, selecting a semipolar growth orientation based on the desired material properties, selecting a suitable substrate for growth of the selected semipolar growth orientation, growing a planar semipolar (Ga,Al,In,B)N template or nucleation layer on the substrate, and growing the semipolar (Ga,Al,In,B)N thin films, heterostructures or devices on the planar semipolar (Ga,Al,In,B)N template or nucleation layer. The method results in a large area of the semipolar (Ga,Al,In,B)N thin films, heterostructures, and devices being parallel to the substrate surface.