A semiconductor laser device includes a multilayer substrate, a first conductive layer (submount) that is disposed on the multilayer substrate, a semiconductor laser element located in a first region of the first conductive layer, a first bump located on a surface of the semiconductor laser element, the surface not facing the first conductive layer, a first electrode electrically connected to the first bump, a second conductive layer located in a second region of the first conductive layer, and a second electrode electrically connected to the first conductive layer via the second conductive layer.

An optical device includes: a first reflector; a second reflector facing the reflector; a light emitter between the first reflector and the second reflector; a base supporting the second reflector with space between the light emitter and the second reflector; a piezoelectric body configured to, in response to application of drive voltage, deform to cause the second region to deform to drive the second reflector so as to change a distance between the first reflector and the second reflector. The base has a first region and a second region having a lower stiffness than the first region. The second region has the second reflector and the piezoelectric body thereon. The optical device is configured to emit a laser beam whose wavelength is changeable with the distance between the first reflector and the second reflector.

A light emitting element includes: a laminated structural body 20 in which a first compound semiconductor layer 21, an active layer 23, and a second compound semiconductor layer 22 are laminated; a first electrode 31 electrically connected to the first compound semiconductor layer 21; and a second electrode 32 and a second light reflecting layer 42 formed on the second compound semiconductor layer 22, in which a protrusion 43 is formed on the first surface side of the first compound semiconductor layer 21, a smoothing layer 44 is formed on at least the protrusion 43, the protrusion 43 and the smoothing layer 44 constitute a concave mirror portion, a first light reflecting layer 41 is formed on at least a part of the smoothing layer 44, and the second light reflecting layer 42 has a flat shape.

A manufacturing method of a nitride-based semiconductor light-emitting element includes: forming an n-type nitride-based semiconductor layer; forming, on the n-type nitride-based semiconductor layer, a light emission layer including a nitride-based semiconductor; forming, on the light emission layer in an atmosphere containing a hydrogen gas, a p-type nitride-based semiconductor layer while doping the p-type nitride-based semiconductor layer with a p-type dopant at a concentration of at least 2.0×10.sup.18 atom/cm.sup.3; and annealing the p-type nitride-based semiconductor layer at a temperature of at least 800 degrees Celsius in an atmosphere not containing hydrogen. In this manufacturing method, a hydrogen concentration of the p-type nitride-based semiconductor layer after the annealing is at most 5.0×10.sup.18 atom/cm.sup.3 and at most 5% of the concentration of the p-type dopant, and a hydrogen concentration of the light emission layer is at most 2.0×10.sup.17 atom/cm.sup.3.

To provide an optical semiconductor device having excellent long-term reliability, the optical semiconductor device includes: a substrate; a mesa structure provided on the substrate; a semiconductor burial layer provided in contact with two sides of the mesa structure; and an electrode containing Au, which is provided above the semiconductor burial layer. The mesa structure includes a first conductivity type semiconductor layer, a multiple-quantum well layer, and a second conductivity type semiconductor layer, which are stacked in the stated order from a substrate side. The semiconductor burial layer includes a first semi-insulating InP layer provided in contact with side portions of the mesa structure, a first anti-diffusion layer provided in contact with the first semi-insulating InP layer, and a second semi-insulating InP layer provided on the first anti-diffusion layer. The first anti-diffusion layer has an Au diffusion constant that is smaller than that of the first semi-insulating InP layer.

A laser element comprises a substrate; and an n-type semiconductor layer, a light emitting layer, a p-type semiconductor layer, and an electrode layer successively laminated on one principal surface of the substrate, wherein the p-type semiconductor layer includes a ridge raised in a stripe shape, the ridge including a contact layer formed in a layer including a principal surface on a side opposite to the substrate, a stepped portion defined by recessing the contact layer is formed in at least part of a boundary between a lateral surface among surfaces defining outer edges of the ridge, the lateral surface extending along a lengthwise direction of the ridge, and the principal surface of the ridge, and the electrode layer covers the principal surface of the ridge and the stepped portion.

A semiconductor optical device includes a substrate including a waveguide made of silicon and a semiconductor layer joined to the substrate so as to overlap the waveguide and including a diffraction grating formed of a first semiconductor layer and a second semiconductor layer having different refractive indices. The waveguide includes a bent portion and a plurality of straight portions that are connected to each other by the bent portion and that extend straight. The first semiconductor layer and the second semiconductor layer are each made of a compound semiconductor. The second semiconductor layer is embedded in the first semiconductor layer and includes a plurality of portions arranged in a direction in which the plurality of straight portions extend. The diffraction grating is positioned above the plurality of straight portions.

A semiconductor laser according to one embodiment of the present disclosure includes: a first semiconductor layer of a first conductivity type; an active layer; and a second semiconductor layer of a second conductivity type stacked on the first semiconductor layer with the active layer interposed therebetween, and provided with a strip-shaped ridge. The semiconductor laser further includes: a pair of resonator end faces facing each other across the ridge; and an electrode layer electrically coupled to an upper surface of the ridge.

A surface emitting laser includes a substrate, a mesa of semiconductor layers including a lower reflector layer, an active layer, an upper reflector layer, and an upper contact layer that are successively laminated on the substrate, and an electrode provided on the upper contact layer. The upper contact layer includes GaAs. The electrode includes an alloy layer including Pt, in contact with the upper contact layer.

Disclosed are a manufacturing method for a laser chip and a laser chip. The manufacturing method comprises: step S1, forming a first electroplating substrate on an epitaxial layer; step S2, forming an organic pattern layer on the first electroplating substrate, wherein the pattern layer defines a hollowed-out area and a part of the first electroplating substrate is exposed to the pattern layer by means of the hollowed-out area; step S3, forming a first metal coating on the first electroplating substrate, wherein the first metal coating completely covers the pattern layer and the part of the first electroplating substrate not covered by the pattern layer; and step S4, removing the pattern layer to have a hollow channel formed between the first metal coating and the first electroplating substrate, wherein the channel is provided with at least one inlet and at least one outlet running through the first metal coating.