An array of monolithic wavelength division multiplexing (WDM) vertical cavity surface emitting lasers (VCSELs) with spatially varying gain peak and Fabry Perot wavelength is provided. Each VCSEL includes a lower distributed Bragg reflector (DBR), a Fabry Perot tuning/current spreading layer, and a structure comprising a multiple quantum well (MQW) layer sandwiched between a lower separate confinement heterostructure (SCH) layer and an upper SCH layer. The structure is sandwiched between the DBR and the Fabry Perot tuning/current spreading layer. Each MQW experiences a different amount of quantum well intermixing and concomitantly a different wavelength shift. Each VCSEL further includes a top mirror on the Fabry Perot tuning/current spreading layer. A method is also provided for manufacturing the array.

A resonator is provided having a waveguide with a first boundary, a second boundary parallel to the first boundary, a first end, a second end, and a waveguide cavity at least partly between the first boundary and the second boundary. A first grating, having a period of distance a, is at the first boundary of the waveguide, and a second grating, having a period of distance a, is at the second boundary of the waveguide. The first and second boundaries are separated by a constant distance d. The first boundary may have a periodic profile aligned with a periodic profile of the second boundary. The periodic profile of the first boundary and the second boundary may be a sinusoidal profile, a square profile, or profile of another shape. The resonator may be suitable for use in a distributed feedback laser.

A vertical cavity surface emitting laser includes: a supporting base; and a post including an upper distributed Bragg reflecting region, an active layer, and a lower distributed Bragg reflecting region. The upper distributed Bragg reflecting region, the active layer, and the lower distributed Bragg reflecting region are arranged on the supporting base. The lower distributed Bragg reflecting region includes first semiconductor layers and second semiconductor layers alternately with each of the first semiconductor layers having a refractive index lower than that of each of the second semiconductor layers. The upper distributed Bragg reflecting region includes first layers and second layers alternately with each of the first layers having a group III-V compound semiconductor portion and a group III oxide portion. The group III-V compound semiconductor portion contains aluminum as a group III constituent element, and the group III oxide portion surrounds the group III-V compound semiconductor portion.

A diode laser comprises an n-type first cladding layer, an n-type first waveguide layer arranged on the first cladding layer, an active layer suitable for radiation generation and arranged on the first waveguide layer, a p-type second waveguide layer arranged on the active layer, a p-type second cladding layer which is arranged on the second waveguide layer, an n-type first intermediate layer being formed as a transition region between the first waveguide layer and the active layer, and a p-type second intermediate layer being formed as a transition region between the second waveguide layer and the active layer. The diode laser according to the invention is characterized in that the asymmetry ratio of the thickness of the first intermediate layer to the sum of the thickness of the first intermediate layer and the thickness of the second intermediate layer is less than or greater than 0.5.

A light-emitting element includes a mesa structure in which a first compound semiconductor layer of a first conductivity type, an active layer, and a second compound semiconductor layer of a second conductivity type are disposed in that order, wherein at least one of the first compound semiconductor layer and the second compound semiconductor layer has a current constriction region surrounded by an insulation region extending inward from a sidewall portion of the mesa structure; a wall structure disposed so as to surround the mesa structure; at least one bridge structure connecting the mesa structure and the wall structure, the wall structure and the bridge structure each having the same layer structure as the portion of the mesa structure in which the insulation region is provided; a first electrode; and a second electrode disposed on a top face of the wall structure.

The invention relates to a process for fabricating an optoelectronic device (1) for emitting infrared radiation, comprising the following steps: i) producing a first stack (10) comprising: alight source (11), a first bonding sublayer (17) made from a metal of interest chosen from gold, titanium and copper, ii) producing a second stack (20) comprising: a GeSn-based active layer (23) obtained by epitaxy at an epitaxy temperature (T.sub.epi), a second bonding sublayer (25) made from said metal of interest, iii) determining an assembly temperature (Tc) substantially comprised between an ambient temperature (T.sub.amb) and said epitaxy temperature (T.sub.epi), such that a direct bonding energy per unit area of said metal of interest is higher than or equal to 0.5 J/m.sup.2; iv) joining, by direct bonding, at said assembly temperature (Tc), said stacks (10, 20).

A vertical cavity surface-emitting laser including: a substrate having a main surface; and a post structure mounted on the main surface. The post structure includes an active layer and a carrier confinement structure. The carrier confinement structure includes a first region and a second region having a higher resistivity than the first region. The first region has an edge, and a first to a third reference line segments. A first length of the first reference line segment is longest among lengths of line segments joining any two points on the edge and extending in a direction of the III-V group semiconductor. The first length is greater than a sum of a second length of the second reference line segment and a third length of the third reference line segment. The third length is smaller than the second length and is zero or more.

A semiconductor optical amplifier includes: a substrate; a light source unit formed on the substrate; and an optical amplification part that amplifies light propagating in a predetermined direction from the light source unit and emits the amplified light in an emission direction intersecting with the substrate surface. The optical amplification part includes a conductive region extending in the predetermined direction along the substrate surface from the light source unit, and a nonconductive region formed around the conductive region. The conductive region includes a first region extending from the light source unit and having a predetermined width as seen from a direction perpendicular to the substrate surface, and a second region connected to the first region and having a width widened relative to the predetermined width of the first region, the second region being configured to expand the propagation light in a direction intersecting with the predetermined direction.

An improvement is made to a non-Raman spectroscopy method and apparatus in which a quantum entangled transmission package formed in a quantum well in a laser is directed to a target and in which the apparatus receives emission packages from the target. A control circuit triggers the laser to emit a laser beam. The transmission package is sent via the laser beam by an emission fiber and the emission package is received by a collection fiber. The collection fiber and the transmission fiber may be included in a Raman probe. The collection fiber provides an input to a monochromator comprising a diffraction grating. The diffraction grating is constructed to permit selection of any of a wide range of wavelengths. A spectrometer receives an output from the diffraction grating. The spectrometer output is measured by a photomultiplier to provide an input to the control module. A number of different spectra are selectively generated. Also, the transmission package may be formed with a power level to affect structure of a preselected target.

A reflector for optical devices is disclosed. The reflector includes a distributed Bragg reflector and a metal reflector. The metal reflector is contained within one or more apertures defined by a material having good adhesion to a semiconductor material. method for bonding the resulting structure to a heat spreader is also disclosed.