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.

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.

An optical filter includes a first loop mirror, a second loop mirror, a first waveguide optically coupled to the first loop mirror and the second loop mirror, and a first access waveguide. The first loop mirror includes a first loop waveguide and a first multiplexer/demultiplexer. The second loop mirror includes a second loop waveguide and a second multiplexer/demultiplexer. The first loop waveguide is optically coupled to the first multiplexer/demultiplexer. The second loop waveguide is optically coupled to the second multiplexer/demultiplexer. The first waveguide is optically coupled to the first multiplexer/demultiplexer and the second multiplexer/demultiplexer. The first access waveguide is optically coupled to the first waveguide.

A light emitting device includes a wiring substrate, a light emitting element array that includes a first side surface and a second side surface facing each other, and a third side surface and a fourth side surface connecting the first side surface and the second side surface to each other and facing each other, the light emitting element array being provided on the wiring substrate, a driving element that is provided on the wiring substrate on the first side surface side and drives the light emitting element array, a first circuit element and a second circuit element that are provided on the wiring substrate on the second side surface side to be arranged in a direction along the second side surface, and a wiring member that is provided on the third side surface side and the fourth side surface side and extends from a top electrode of the light emitting element array toward an outside of the light emitting element array.

A semiconductor light-emitting element having a structure in which a substrate, a first reflector, a resonator cavity including an active layer, a second reflector and a transparent conductive film are stacked in this sequence, the semiconductor light-emitting element comprising: a first current constriction portion configured with an oxidation constriction layer; and a second current constriction portion configured with an insulation film, which is formed on an upper face of the second reflector and has an opening, and a contact portion between the transparent conductive film and a semiconductor layer with which the transparent conductive film is in contact, wherein a width d2 of the second current constriction portion is smaller than a width d1 of the first current constriction portion.

A semiconductor laser element includes: a substrate; and a laser array portion that includes a plurality of light emitting portions arranged side by side, and is stacked above the substrate, wherein a stacked body of the substrate and the laser array portion includes a pair of resonator end faces on opposite faces, and a groove portion that extends from the laser array portion into the substrate is provided on at least one of the pair of resonator end faces between two adjacent light emitting portions among the plurality of light emitting portions.

A surface emitting laser includes a lower reflector layer, an active layer , an upper reflector layer , and a wiring. The lower reflector layer, the active layer, and the upper reflector layer form a mesa, a terrace, and a connecting portion. A first groove is provided between the mesa and the terrace. The connecting portion connects the mesa and the terrace, and extends in a direction inclined from <011> direction of the substrate. A high-resistance region is formed in the terrace, in the connecting portion, and in a peripheral portion of the mesa. The wiring is provided on top surfaces of the terrace, the connecting portion, and the mesa. The mesa includes an oxide region extending from a side surface of the mesa and a current confinement structure including an aperture surrounded by the oxide region.

A semiconductor device includes a substrate, an epitaxial stack disposed on the substrate, a first connection layer between the epitaxial stack and the substrate and a first electrode disposed on the first connection layer. The substrate has a first side surface and a second side surface. The epitaxial stack has a semiconductor structure with a first lateral surface adjacent to the first side surface and a second lateral surface opposing the first lateral surface and adjacent to the second side surface. The first connection layer has a first protruding portion extending beyond the first lateral surface and a second protruding portion extending beyond the second lateral surface. The first electrode is in contact with the first protruding portion and the second protruding portion.

A light-emitting module includes a substrate, a first surface-emitting laser mounted on the substrate, the first surface-emitting laser having a first engaging portion protruded outward at an end, and a second surface-emitting laser mounted on the substrate, the second surface-emitting laser having a second engaging portion recessed inward at an end. The first surface-emitting laser and the second surface-emitting laser are adjacent to each other. The first engaging portion and the second engaging portion are engaged with each other.

A semiconductor optical device includes an SOI substrate having a waveguide of silicon, and at least one gain region of a group III-V compound semiconductor having an optical gain bonded to the SOI substrate. The waveguide has a bent portion and multiple linear portions extending linearly and connected to each other through the bent portion. The gain region is disposed on each of the multiple linear portions.