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 laser radar includes: a light source including a laser diode; an optical system configured to shape laser light emitted from the laser diode, into a line beam that is long in one direction, and project the line beam to a target area; and a scanner configured to perform scanning with the line beam in a short side direction of the line beam. The laser diode is disposed such that a fast axis of the laser diode extends along a direction corresponding to the short side direction of the line beam.

A semiconductor optical device may include a semiconductor substrate; a mesa stripe structure that extends in a stripe shape in a first direction on the semiconductor substrate and includes a contact layer on a top layer; an adjacent layer on the semiconductor substrate and adjacent to the mesa stripe structure in a second direction orthogonal to the first direction; a passivation film that covers at least a part of the adjacent layer; a resin layer on the passivation film; an electrode that is electrically connected to the contact layer and extends continuously from the contact layer to the resin layer; and an inorganic insulating film that extends continuously from the resin layer to the passivation film under the electrode, is spaced apart from the mesa stripe structure, and is completely interposed between the electrode and the resin layer.

A semiconductor laser device includes an N-type cladding layer, an active layer, and a P-type cladding layer. The active layer includes a well layer, a P-side first barrier layer above the well layer, and a P-side second barrier layer above the P-side first barrier layer. The P-side second barrier layer has an AI composition ratio higher than an AI composition ratio of the P-side first barrier layer. The P-side second barrier layer has band gap energy greater than band gap energy of the P-side first barrier layer. The semiconductor laser device has an end face window structure in which band gap energy of a portion of the well layer in a vicinity of an end face that emits the laser light is greater than band gap energy of a central portion of the well layer in a resonator length direction.

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 Bragg grating includes a lower waveguide layer, a middle waveguide layer disposed on the lower waveguide layer, an upper waveguide structure disposed on the middle waveguide layer opposite to the lower waveguide layer, and a buried layer. The upper waveguide structure includes upper waveguide elements that are arranged on a surface of the middle waveguide layer, and that are spaced apart from one another by cavities. The buried layer fills the cavity. The middle waveguide layer has a refractive index lower than that of each of the lower waveguide layer and the upper waveguide elements. The lower waveguide layer has a doping type the same as that of the middle waveguide layer. A method for manufacturing the Bragg grating is also provided.

A semiconductor light emitting device includes a substrate and a semiconductor multilayer stacked on the substrate. The semiconductor multilayer includes an n-side clad layer stacked above the substrate, an active layer stacked above the n-side clad layer, and a p-side clad layer stacked above the active layer. The semiconductor multilayer includes a first plane perpendicular to a stacking direction in which the semiconductor multilayer is stacked, and a lattice constant inside the first plane is an anisotropy constant.

A laser structure may include a substrate, an active region arranged on the substrate, and a waveguide arranged on the active region. The waveguide may include a first surface and a second surface that join to form a first angle relative to the active region. A material may be deposited on the first surface and the second surface of the waveguide.

A device includes: a laminate including first and second regions adjacent to respective both sides of an isolation groove; a mesa stripe structure adjacent to the first region on the laminate and extending in the first direction; a bank structure adjacent to the second region on the laminate and extending in the first direction; and an electrode pattern. The isolation groove has an inner surface including a first wall surface adjacent to the first region, a second wall surface adjacent to the second region, and a bottom surface between the first and second regions. The ridge electrode extends from the side of the mesa stripe structure, along a second direction, toward the bank structure, and not beyond the second wall surface. The connection electrode is narrower in width in the first direction than any one of the ridge electrode and the pad electrode.

A quantum-cascade laser element includes: a semiconductor substrate; a semiconductor mesa formed on the semiconductor substrate to include an active layer having a quantum-cascade structure and to extend along a light waveguide direction; an embedding layer formed to interpose the semiconductor mesa along a width direction of the semiconductor substrate; a cladding layer formed at least on the semiconductor mesa; and a metal layer formed at least on the cladding layer. A thickness of the cladding layer is thinner in a second region located outside a first region in the width direction of the semiconductor substrate than in the first region of which at least a part overlaps the semiconductor mesa when viewed in a thickness direction of the semiconductor substrate. The metal layer extends over the first region and the second region.