In the light emitting device, each of columnar parts 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 disposed between the first semiconductor layer and the second semiconductor layer, the first semiconductor layer is disposed between a substrate and the light emitting layer, a laminated structure has a third semiconductor layer of the first conductivity type disposed between the substrate and the plurality of columnar parts, a first electrode is electrically connected to the first semiconductor layer via the third semiconductor layer, a contact hole is disposed in an insulating layer at a position overlapping the first electrode when viewed from a stacking direction of the first semiconductor layer and the light emitting layer, the first wiring layer is provided to the insulating layer, and the first wiring layer is electrically connected to the first electrode via the contact hole.

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 surface emitting quantum cascade laser includes an active layer, a first semiconductor layer, and first electrode. The active layer has a plurality of quantum well layers stacked therein. The active layer is capable of emitting laser light by inter-subband transition. The first semiconductor layer is provided on the active layer and having a first surface provided with a plurality of pits so as to constitute a two-dimensional lattice. The first electrode is provided on the first semiconductor layer and having a periodic opening. Each pit is asymmetric with respect to a line parallel to a side of the lattice. The laser light is emitted in a direction generally perpendicular to the active layer from a pit exposed to the opening.

An embodiment semiconductor optical device includes an optical waveguide including a core, and an active layer extending in the waveguide direction of the optical waveguide for a predetermined distance and arranged in a state in which the active layer can be optically coupled to the core. The core and the active layer are arranged in contact with each other. The core is formed of a material with a refractive index of about 1.5 to 2.2, such as SiN, for example. In addition, the core is formed to a thickness at which a higher-order mode appears. The higher-order mode is an E.sub.12 mode, for example.

A light emitting apparatus according to an aspect of the present disclosure includes a substrate, a columnar section group including a plurality of columnar sections each having a laminated structure of a first semiconductor layer, a light emitting layer, and a second semiconductor layer, and an electrode via which electric current is injected into the plurality of columnar sections. The plurality of columnar sections include a plurality of first columnar sections and a plurality of second columnar sections disposed around the plurality of first columnar sections. The second columnar sections each have the shape of each of the first columnar sections except that part of the shape is missing. The second columnar sections are lower than the first columnar sections. The electrode is electrically insulated from the plurality of second columnar sections.

According to one embodiment, a surface-emitting quantum cascade laser includes a substrate; a mesa portion of a semiconductor stacked body located on the substrate, and a reflective film located at a sidewall of the mesa portion. The mesa portion includes a light-emitting layer emitting light due to an intersubband transition of a carrier, and a photonic crystal layer including a two-dimensional diffraction grating.

The invention relates to an edge-emitting semiconductor laser diode, having: —a semiconductor layer sequence, which comprises a bottom surface, a ridge waveguide on a top surface facing away from the bottom surface, and a side surface which is arranged transverse to the top surface, and —a first recess, which extends from the bottom surface to the top surface, wherein —a first region of the semiconductor layer sequence is removed from the side surface in the region of the first recess. The invention further relates to a method for producing a plurality of edge-emitting semiconductor laser diodes.

A laser includes a distributed Bragg minor and is configured to emit monochromatic light radiation along a longitudinal direction. The laser has layers, stacked along a first transverse direction normal to the longitudinal direction and made of III-V materials, including an active region configured to emit the radiation. The mirror is formed by periodic lateral corrugations which extend mainly along the longitudinal direction and having a dimension along a second transverse direction normal to the longitudinal direction. The lateral corrugations of the Bragg minor extend from a top surface of the waveguide pattern along the first transverse direction on a height strictly less than the depth, at which the active region is located starting from the top surface, such that a portion of lateral flanks of the waveguide is free of any lateral corrugations at the active region.

A method for numerical control milling, forming and polishing of a large-diameter aspheric lens to solve long time-consuming and severe tool wear in the machining of a meter-scale large-diameter aspheric surface is disclosed. An aspheric surface is discretized into a series of rings with different radii, and the rings are sequentially machined through generating cutting by using an annular grinding wheel tool; the rings are equally spaced, there are a total of N rings, and the width of any ring is jointly determined by the N.sup.th ring, the (N-1)th ring, positioning accuracy, and a generatrix equation of the aspheric lens, and the n.sup.th ring has a curvature radius of Rn =sqrt(R0.sup.2-k*(n*dx).sup.2); and the aspheric surface is enveloped by a large number of rings. The tool used for machining has a diameter greater than the semi-diameter of the aspheric surface, and contact area between tool and workpiece surface is rings.

A laser with a hexagonal semiconductor microdisk to solve the problems of a low quality factor of a hexagonal whispering-gallery mode and light exiting difficulty of a triangular whispering-gallery mode is disclosed. Based on physical characteristics of stimulated radiation of gain materials with a high refractive index, the apparatus uses a distributed Bragg reflection layer to reduce an optical loss of a microcavity laser, and uses a hexagonal semiconductor microdisk as an optical resonator and laser gain material. As an optical pump source, the laser provides an optical gain, and when the gain exceeds a microcavity laser threshold, generates laser light for exiting. By controlling a laser spot of the pump source to be located at a corner of the hexagonal microdisk, the laser light in a double-triangular whispering-gallery optical resonance mode is generated after stimulated radiation for exiting.