A laser device based on silicon photonics with an in-cavity power monitor includes a gain chip mounted on a silicon photonics substrate and configured to emit light in an active region bounded between a frontend facet with low reflectivity and a backend facet with anti-reflective characteristics. The laser device further includes a wavelength tuner formed with waveguides in the silicon photonics substrate optically coupled to the backend facet to receive light from the gain chip and configured to have a reflector with high reflectivity to reflect the light in an extended cavity formed with the frontend facet through which a laser with a tuned wavelength and amplified power is outputted. Additionally, the laser device includes a photodiode formed in the silicon photonics substrate and coupled to the waveguides in the extended cavity right in front of the reflector to measure power of light thereof.

A bound states in the continuum (BIC) surface emitting laser includes a light emitter configured to generate BIC light waves. The laser also includes an array of holes with equal radii extending through the light emitter such that light emitted by the light emitter upon receipt of power is emitted as a coherent vortex beam at an angle to a surface normal of the light emitter that is determined at least in part by the radius of the holes in the array.

A laser includes a substrate, first and second claddings, a gain medium, and multiple supports. The first cladding is spaced apart from the substrate by an air gap. A thickness of the first cladding in a vertical direction is in a range from 0.05-0.15 micrometers. The gain medium is disposed on the first cladding opposite the air gap. The second cladding is disposed on the gain medium opposite the first cladding. A thickness of the second cladding in the vertical direction is in a range from 0.05-0.15 micrometers. The supports are coupled to each of the substrate, the first cladding, the gain medium, and the second cladding to retain the first cladding, the gain medium, and the second cladding spaced apart from the substrate.

A semiconductor laser element includes a semiconductor laminated structure that has a substrate, an n type cladding layer disposed at a front surface side of the substrate, an active layer disposed at an opposite side of the n type cladding layer to the substrate, and p type cladding layers disposed at an opposite side of the active layer to the n type cladding layer. The active layer includes a quantum well layer having a tensile strain for generating TM mode oscillation and the n type cladding layer and the p type cladding layers are respectively constituted of AlGaAs layers.

A monolithic edge emitting semiconductor laser comprising multiple laser diodes using aluminum indium gallium arsenide phosphide AlInGaAs/InGaAsP/InP material system, emitting in long wavelengths (1250 nm to 1720 nm). Each laser diode contains an active region comprising aluminium indium gallium arsenide quantum wells (AlInGaAs QW) and aluminium indium gallium arsenide (AlInGaAs) barriers and connected to the subsequent monolithic laser diode by highly doped, low bandgap and low resistive indium gallium arsenide junction called tunnel junction.

A process for producing a component includes a structure made of III-V material(s) on the surface of a substrate, the structure comprising at least one upper contact level defined on the surface of a first III-V material and a lower contact level defined on the surface of a second III-V material, comprising: successive operations of encapsulation of the structure with at least one dielectric; making primary apertures in a dielectric for the two contacts; making secondary apertures in a dielectric for the two contacts; at least partial filling of the apertures with at least one metallic material so as to produce upper contact bottom metallization and at least one upper contact pad in contact with the metallization for each of said contacts. A component produced by the process is also provided. The component may be a laser diode.

An optical semiconductor element including a semiconductor substrate, a first cladding layer of a first conductive type provided on the semiconductor substrate, an active layer provided on the first cladding layer, a second cladding layer of a second conductive type provided on the active layer, a first mesa constituted of a part of the first cladding layer, the active layer, and the second cladding layer, an auxiliary cladding layer of the second conductive type provided on the first mesa, a second mesa constituted of the auxiliary cladding layer, and a semi-insulating layer provided on the first cladding layer and on both sides of the first mesa and both sides of the second mesa, wherein a width of the second mesa is greater than a width of the first mesa.

A method for producing a semiconductor optical device includes the steps of bonding a semiconductor chip to an SOI substrate having a waveguide, the semiconductor chip having an optical gain and including a first cladding layer, a core layer, and a second cladding layer that contain III-V group compound semiconductors and are sequentially stacked in this order, forming a covered portion with a first insulating layer on the second cladding layer, etching partway in the thickness direction the second cladding layer exposed from the first insulating film, forming a second insulating film covering from the covered portion to a part of a remaining portion of the second cladding layer, and forming a first tapered portion that is disposed on the waveguide and tapered along the extending direction of the waveguide by etching the core layer and the second cladding layer exposed from the second insulating film.

A first conduction type first cladding layer and a second conduction type second cladding layer are arranged on the two sides in the vertical direction of a core portion having a multiple quantum-well structure, and a first conduction type third cladding layer and a second conduction type fourth cladding layer are arranged on the two sides in the horizontal direction of the core portion. A first electrode connected to the third cladding layer is formed. A second electrode connected to the fourth cladding layer is formed. A reverse bias is applied between the first and third cladding layers and the second and fourth cladding layers.

An optical semiconductor device outputting a predetermined wavelength of laser light includes a quantum well active layer positioned between a p-type cladding layer and an n-type cladding layer in thickness direction. The optical semiconductor device includes a separate confinement heterostructure layer positioned between the quantum well active layer and the n-type cladding layer. The optical semiconductor device further includes an electric-field-distribution-control layer positioned between the separate confinement heterostructure layer and the n-type cladding layer and configured by at least two semiconductor layers having band gap energy greater than band gap energy of a barrier layer constituting the quantum well active layer. The quantum well active layer is doped with 0.3 to 1×10.sup.18/cm.sup.3 of n-type impurity.