An edge-emitting GaAs-based semiconductor laser uses a tunnel junction in combination with an inverted p-n junction to address oxidation problems associated with the use of a high aluminum content p-type cladding arrangement. In particular, a tunnel junction is formed on an n-type GaAs substrate, with p-type cladding and waveguiding layers formed over the tunnel junction. N-type waveguiding and cladding layers are thereafter grown on top of the active region. Since the p-type layers are positioned below the active region and not exposed to air during processing, a relative high aluminum content may be used, which improves the thermal and electrical properties of the device. Since the n-type material does not require a high aluminum content, it may be further processed to form a ridge structure without introducing any substantial oxidation of the structure.

A semiconductor device includes a substrate comprising a layer made of Ge and a semiconductor multilayer structure grown on the layer made of Ge. The semiconductor multilayer structure includes at least one first layer comprising a material selected from a group consisting of Al.sub.xGa.sub.1-xAs, Al.sub.xGa.sub.1-x-yIn.sub.yAs, Al.sub.xGa.sub.1-x-yIn.sub.yAs.sub.1-zP.sub.z, Al.sub.xGa.sub.1-x-yIn.sub.yAs.sub.1-zN.sub.z, and Al.sub.xGa.sub.1-x-yIn.sub.yAs.sub.1-z-cN.sub.zP.sub.c, Al.sub.xGa.sub.1-x-yIn.sub.yAs.sub.1-z-cN.sub.zSb.sub.c, and Al.sub.xGa.sub.1-x-yIn.sub.yAs.sub.1-z-cP.sub.zSb.sub.c, wherein for any material a sum of the contents of all group-III elements equals 1 and a sum of the contents of all group-V elements equals 1. The semiconductor multilayer structure also includes at least one second layer comprising a material selected from a group consisting of GaInAsNSb, GaInAsN, AlGaInAsNSb, AlGaInAsN, GaAs, GaInAs, GaInAsSb, GaInNSb, GaInP, GaInPNSb, GaInPSb, GaInPN, AlInP, AlInPNSb, AlInPN, AlInPSb, AlGaInP, AlGaInPNSb, AlGaInPN, AlGaInPSb, GaInAsP, GaInAsPNSb, GaInAsPN, GaInAsPSb, GaAsP, GaAsPNSb, GaAsPN, GaAsPSb, AlGaInAs and AlGaAs.

An optical full-field transmitter for an optical communications network includes a primary laser source configured to provide a narrow spectral linewidth for a primary laser signal, and a first intensity modulator in communication with a first amplitude data source. The first intensity modulator is configured to output a first amplitude-modulated optical signal from the laser signal. The transmitter further includes a first phase modulator in communication with a first phase data source and the first amplitude-modulated optical signal. The first phase modulator is configured to output a first two-stage full-field optical signal. The primary laser source has a structure based on a III-V compound semiconductor.

A time-of-flight 3D imaging system includes a light source having a plurality of P-N junctions in electrical series, an imaging sensor, and a time measurement device configured to measure the elapsed time-of-flight between a pulse of output light being emitted from the plurality of P-N junctions in series and incoming light including the pulse of output light being detected at the imaging sensor.

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 optical semiconductor device is applied to a ridge-stripe type laser.

In some embodiments, a semiconductor structure includes: a first epitaxial oxide semiconductor layer; a metal layer; and a contact layer adjacent to the metal layer, and between the first epitaxial oxide semiconductor layer and the metal layer. The contact layer can include an epitaxial oxide semiconductor material. The contact layer can also include a region comprising a gradient in a composition of the epitaxial oxide semiconductor material adjacent to the metal layer, or a gradient in a strain of the epitaxial oxide semiconductor material over a region adjacent to the metal layer.

A monolithically integrated optical device. The device has a gallium and nitrogen containing substrate member having a surface region configured on either a non-polar or semi-polar orientation. The device also has a first waveguide structure configured in a first direction overlying a first portion of the surface region. The device also has a second waveguide structure integrally configured with the first waveguide structure. The first direction is substantially perpendicular to the second direction.

A light emitting device includes: a substrate including a main surface; a first projection positioned on the main surface, the first projection including an upper surface and first and second lateral surfaces, wherein the first lateral surface of the first projection comprises a first reflective part, and the second lateral surface of the first projection comprises a second reflective part; a first laser element positioned on the main surface at a first reflective part side with respect to the first projection, the first laser element being configured to irradiate first laser light to the first reflective part; a second laser element positioned on the main surface at a second reflective part side with respect to the first projection, the second laser element being configured to irradiate second laser light to the second reflective part; and a first optical member bonded to the upper surface of the first projection.

A light emitting device is provided that makes it possible to reduce absorption of light by an electrode. The light emitting device includes a substrate, and a laminated structure provided to the substrate, wherein the laminated structure includes a first semiconductor layer, a second semiconductor layer different in conductivity type from the first semiconductor layer, and an active layer disposed between the first semiconductor layer and the second semiconductor layer, the first semiconductor layer is disposed between the substrate and the active layer, a recessed part is disposed at an opposite side to the substrate side of the laminated structure, the recessed part is provided with a low refractive-index part lower in refractive index than the second semiconductor layer, a depth of the recessed part is no larger than a distance between a surface at an opposite side to the substrate side of the laminated structure and the active layer, and an electrode is disposed at an opposite side to the substrate side of the laminated structure.

A semiconductor chip (100) is provided, having a first semiconductor layer (1), which has a lateral variation of a material composition along at least one direction of extent. Additionally provided is a method for producing a semiconductor chip (100).