A light emitting device according to an embodiment of the present disclosure includes: a substrate; a first contact layer; a buffer layer in which at least any of a carrier concentration, a material composition, and a composition ratio is different from that of the first contact layer; and a semiconductor stacked body. The substrate has a first surface and a second surface that are opposed to each other. The first contact layer is stacked on the first surface of the substrate. The buffer layer is stacked on the first contact layer. The semiconductor stacked body is stacked above the first surface of the substrate with the first contact layer and the buffer layer interposed in between. The semiconductor stacked body has a light emitting region configured to emit laser light.

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.

A method of producing a laser diode bar includes producing a plurality of emitters arranged side by side, emitters each including a semiconductor layer sequence having an active layer that generates laser radiation, a p-contact on a first main surface of the laser diode bar and an n-contact on a second main surface of the laser diode bar opposite the first main surface, testing at least one optical and/or electrical property of the emitters, wherein emitters in which the optical and/or electrical property lies within a predetermined setpoint range are assigned to a group of first emitters, and emitters in which the at least one optical and/or electrical property lies outside the predetermined setpoint range are assigned to a group of second emitters, and electrically contacting first emitters, wherein second emitters are not electrically contacted so that they are not supplied with current during operation of the laser diode bar.

This optical semiconductor element includes: a substrate; a first ridge formed on the substrate and having a first first-conductivity-type cladding layer, a first core layer, a first second-conductivity-type cladding layer, and a first contact layer in this order from a lower side, with first ridge grooves provided on both lateral sides of the first ridge; and a first electrode formed in contact with the first contact layer, on the first ridge, without spreading to the first ridge grooves, the first electrode including a first solder layer.

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 photonic crystal surface-emitting laser includes a substrate, an n-type cladding layer, an active layer, an index matching layer and a photonic crystal structure. The n-type cladding layer is disposed over the substrate. The active layer is disposed over the n-type cladding layer. The index matching layer is disposed over the n-type cladding layer and is arranged around the active layer. The index matching layer is electrically insulating, and an effective refractive index of the index matching layer is substantially identical to an effective refractive index of the active layer. The photonic crystal structure is disposed over the active layer and the index matching layer.

A semiconductor device includes an electrode which is arranged on an organic material with an insulation film interposed therebetween and which does not easily peel away from the organic material along with the insulation film. An insulation film in a region including pad portions of a phase shift electrode and a modulation electrode has openings at the centers of the pad portions of the phase shift electrode and the modulation electrode, the edge portions of which are formed on the phase shift electrode and the modulation electrode. In this way, the adjoining edges of the phase shift electrode and modulation electrode and the insulation film are all covered by the insulation film so as not to be exposed to the atmosphere. By covering the cracks that occur in the insulation film in the production process with the insulation film made of SiO.sub.2, SiN.sub.X, SiON.sub.X or the like, an organic solvent such as acetone or ethanol used in the process can be prevented from seeping in between the insulation film and the organic material through the cracks in the insulation film.

Disclosed herein are various embodiments for stronger and more powerful high speed laser arrays. For example, an apparatus is disclosed that comprises an active mesa structure in combination with an electrical waveguide, wherein the active mesa structure comprises a plurality of laser regions within the active mesa structure itself, each laser region of the active mesa structure being electrically isolated within the active mesa structure itself relative to the other laser regions of the active mesa structure.

Provided is a variable-wavelength surface emission laser having a wide wavelength variation range. A partial region of a thin-plate substrate (22) and a movable mirror (20), the partial region being positioned between an air gap (G1) and a movable gap (G2), can move toward the air gap (G1) side or the movable gap (G2) side.