3270results about "Laser active region structure" patented technology

An inventive semiconductor laser diode includes a Group III nitride semiconductor layered structure having a major crystal growth plane defined by a non-polar or semi-polar-plane. The Group III nitride semiconductor layered structure includes: a p-type cladding layer and an n-type cladding layer; an In-containing p-type guide layer and an In-containing n-type guide layer held between the p-type cladding layer and the n-type cladding layer; and an In-containing light emitting layer held between the p-type guide layer and the n-type guide layer.

Optical resonators that are enhanced with photoluminescent phosphors and are designed and configured to output light at one or more wavelengths based on input / pump light, and systems and devices made with such resonators. In some embodiments, the resonators contain multiple optical resonator cavities in combination with one or more photoluminescent phosphor layers or other structures. In other embodiments, the resonators are designed to simultaneously resonate at the input / pump and output wavelengths. The photoluminescent phosphors can be any suitable photoluminescent material, including semiconductor and other materials in quantum-confining structures, such as quantum wells and quantum dots, among others.

An information processor of a high reliability and a high recording density, and a blue color, blue-violet color and violet color based semiconductor light emitting device operable at a low threshold current density, used for the same, are provided. An optical information processor of a high reliability and a high recording density enables a moving picture, such as a high-definition television picture, to be recorded and reproduced satisfactorily. A barrier layer in a quantum-well active layer of a semiconductor light emitting device is doped with n-type impurities at a high density. Alternatively, the face orientation of a quantum-well active layer of a semiconductor light emitting device is a plane inclined from the (0001) plane, whereby the threshold current value of the semiconductor light emitting device can be decreased. The semiconductor light emitting device is typified by a gallium nitride based compound semiconductor laser device.

Organic vertical-cavity surface-emitting lasers ("OVCSELs"), in which a thin layer of organic material is disposed between highly reflective mirrors to thereby form a vertical cavity within a stacked arrangement. The lasers of the present invention each comprise a first mirror layer; a layer of active organic material over the first mirror layer; and a second mirror layer over the layer of first active organic material. The active organic material lases when pumped to thereby produce laser light. The present invention provides for optical semiconductor lasers with desired properties such as narrow bandwidth emission, the minimal use of active organic materials, and the facilitation of wavelength tuning and electrical pumping.

A nitride semiconductor laser device has an improved stability of the lateral mode under high output power and a longer lifetime, so that the device can be applied to write and read light sources for recording media with high capacity. The nitride semiconductor laser device includes an active layer, a p-side cladding layer, and a p-side contact layer laminated in turn. The device further includes a waveguide region of a stripe structure formed by etching from the p-side contact layer. The stripe width provided by etching is within the stripe range of 1 to 3 μm and the etching depth is below the thickness of the p-side cladding layer of 0.1 μm and above the active layer. Particularly, when a p-side optical waveguide layer includes a projection part of the stripe structure and a p-type nitride semiconductor layer on the projection part and the projection part of the p-side optical waveguide layer has a thickness of not more than 1 μm, an aspect ratio is improved in far field image. Moreover, the thickness of the p-side optical waveguide layer is greater than that of an n-side optical waveguide layer.

A semiconductor laser device has a semiconductor laser diode structure made of group III nitride semiconductors having major growth surfaces defined by nonpolar planes or semipolar planes. The semiconductor laser diode structure includes a p-type cladding layer and an n-type cladding layer, a p-type guide layer and an n-type guide layer held between the p-type cladding layer and the n-type cladding layer, and an active layer containing In held between the p-type guide layer and the n-type guide layer. The In compositions in the p-type guide layer and the n-type guide layer are increased as approaching the active layer respectively. Each of the p-type guide layer and the n-type guide layer may have a plurality of InxGa1-xN layers (0≦x≦1). In this case, the plurality of InxGa1-xN layers may be stacked in such order that the In compositions therein are increased as approaching the active layer.

An optical device having a structured active region configured for one or more selected wavelengths of light emissions and formed on an off-cut m-plane gallium and nitrogen containing substrate.

Disclosed is a semiconductor light-emitting element, comprising an n-type-cladding layer; a light guide layer positioned on the n-type cladding layer; a multiple quantum well structure active layer positioned on the light guide layer; a p-type carrier overflow prevention layer positioned on the active layer and having an impurity concentration of 5×1018 cm−3 to not more than 3×1019 cm−3; a p-type light guide layer positioned on the p-type carrier overflow prevention layer and-having an impurity concentration of 1×1018 cm−3 or more and less-than that of the p-type carrier overflow prevention layer; and a p-type cladding layer positioned on the p-type light guide layer and having a band gap narrower than the p-type carrier overflow prevention layer, and a method of manufacturing the same.

A pulse laser beam having a rectangular irradiation region is irradiated on the same point in a non-single crystal semiconductor film multiple times. The pulse laser beam has an energy profile in a longitudinal direction in the beam irradiation region as follows: (a) there are the first region having an energy density of Ea or higher and the second regions on both sides of the first region having an energy density of less than Ea, and (b) an energy density slope has an absolute value of 20 to 300 J / cm3 in a boundary region extending to 1 mum from the boundary line between the first and the second regions.

A semiconductor light emitting device is disclosed, including a semiconductor substrate, an active region comprising a strained quantum well layer, and a cladding layer for confining carriers and light emissions, wherein the amount of lattice strains in the quantum well layer is in excess of 2% against either the semiconductor substrate or cladding layer and, alternately, the thickness of the quantum well layer is in excess of the critical thickness calculated after Matthews and Blakeslee.

The object of this invention is to provide a high-output type nitride light emitting device. The nitride light emitting device comprises an n-type nitride semiconductor layer or layers, a p-type nitride semiconductor layer or layers and an active layer therebetween, wherein a gallium-containing nitride substrate is obtained from a gallium-containing nitride bulk single crystal, provided with an epitaxial growth face with dislocation density of 10<5> / cm<2 >or less, and A-plane or M-plane which is parallel to C-axis of hexagonal structure for an epitaxial face, wherein the n-type semiconductor layer or layers are formed directly on the A-plane or M-plane. In case that the active layer comprises a nitride semiconductor containing In, an end face film of single crystal AlxGa1-xN (0<=x<=1) can be formed at a low temperature not causing damage to the active layer.

It has a structure in which an active layer (5) that emits light by electric current injection is sandwiched between an n-type cladding layer (4) and a p-type cladding layer (6) made of materials having a larger band gap than the active layer (5), wherein the active layer (5) is made, for example, of CdxZn1−xO (0≦x<1). It is further more preferable if the cladding layers (4), (6) are made, for example, of MgyZn1−yO (0≦y<1). This narrows the band gap of the ZnO materials, and an oxide semiconductor capable of being wet-etched, easy to handle with, and excellent in crystallinity can be used as a material for an active layer or a cladding layer of a semiconductor light emitting device such as a blue light emitting diode or a blue laser diode in which an active layer is sandwiched between cladding layers, so that a blue semiconductor light emitting device being excellent in light emission characteristics can be obtained.

The invention concerns a superluminescent light emitting diode (SLED) comprising a semiconductor heterostructure forming a PN junction and a waveguide. The semiconductor heterostructure includes a gain region with a contact means for biasing the PN junction so as to produce light emission including stimulated emission from an active zone of the gain region, and in the active zone a plurality of quantum dot layers, each quantum dot layer made up of a plurality of quantum dots and a plurality of adjoining layers, each adjoining layer adjacent to one of said quantum dot layers. The material composition or a deposition parameter of at least two adjoining layers is different. This ensures an enhanced emission spectral width.

The present invention is directed toward a method for fabricating low-defect nanostructures of wide bandgap materials and to optoelectronic devices, such as light emitting sources and lasers, based on them. The invention utilizes nanolithographically-defined templates to form nanostructures of wide bandgap materials that are energetically unfavorable for dislocation formation. In particular, this invention provides a method for the fabrication of phosphor-less monolithic white light emitting diodes and laser diodes that can be used for general illumination and other applications.

One or more nodes on a communication network are selected and set as one node group. In each of the nodes, group identification information representing the node group to which the node belongs is stored in advance. The group identification information is attached to the header of a data packet to be transmitted, so that nodes constituting a node group that should commonly receive data can be readily identified by comparing the group identification information imparted to the transmitted data packet and the group identification information stored in each receiving node. Given node can choose to become a node of a particular function, such as a clock master node, in which case control is performed to delete, from the node group, a node having so far played the role of the node of the particular function in such a manner that there exists only one node of the particular function per node group.

Disclosed herein is a method for producing a multi-wavelength semiconductor laser device. The method comprises the steps of: forming first and second nitride epitaxial layers in parallel on a substrate for growth of a nitride single crystal; separating the first and second nitride epitaxial layers from the substrate; attaching the separated first and second nitride epitaxial layers to a first conductivity-type substrate; selectively removing the first and second nitride semiconductor epitaxial layers to expose a portion of the first conductivity-type substrate and to form first and second semiconductor laser structures, respectively; and forming a third semiconductor laser structure on the exposed portion of the first conductivity-type substrate.

A nitride compound semiconductor light emitting device includes: a GaN substrate having a crystal orientation which is tilted away from a <0001> direction by an angle which is equal to or greater than about 0.05° and which is equal to or less than about 2°, and a semiconductor multilayer structure formed on the GaN substrate, wherein the semiconductor multilayer structure includes: an acceptor doping layer containing a nitride compound semiconductor; and an active layer including a light emitting region.

A system and method for providing laser diodes with broad spectrum is described. GaN-based laser diodes with broad or multi-peaked spectral output operating are obtained in various configurations by having a single laser diode device generating multiple-peak spectral outputs, operate in superluminescene mode, or by use of an RF source and / or a feedback signal. In some other embodiments, multi-peak outputs are achieved by having multiple laser devices output different lasers at different wavelengths.

The present invention provides new compositions containing colloidal nanocrystals with high photoluminescence quantum yields, new synthetic methods for the preparation of highly luminescent colloidal nanocrystals, as well as methods to control the photoluminescent properties of colloidal nanocrystals. The new synthetic methods disclosed herein allow photoemission brightness (quantum yield) to be correlated with certain adjustable nanocrystal growth parameters associated with a given synthetic scheme.

A semiconductor device comprises an active layer having a quantum well structure, the active layer including a well layer and a barrier layer and being sandwiched by a first conductivity type layer and a second conductivity type layer, wherein a first barrier layer is provided on side of the first conductivity type layer in the active layer and a second barrier layer is provided on the side of the second conductivity type layer in the active layer, at least one well layer is sandwiched thereby, and the second barrier layer has a band gap energy lower than that of the first barrier layer in the form of asymmetric barrier layer structure, where the second conductivity type layer preferably includes a carrier confinement layer having a band gap energy higher than that of the first barrier layer, resulting in a reverse structure in each of conductivity type layer in respect to the asymmetric structure of the active layer to provide a waveguide structure having excellent crystallinity and device characteristics in the nitride semiconductor light emitting device operating at a wavelength of 380 nm or shorter.

An apparatus and method electrically pumping a hybrid evanescent laser. For one example, an apparatus includes an optical waveguide disposed in silicon. An active semiconductor material is disposed over the optical waveguide defining an evanescent coupling interface between the optical waveguide and the active semiconductor material such that an optical mode to be guided by the optical waveguide overlaps both the optical waveguide and the active semiconductor material. A current injection path is defined through the active semiconductor material and at least partially overlapping the optical mode such that light is generated in response to electrical pumping of the active semiconductor material in response to current injection along the current injection path at least partially overlapping the optical mode.

The present invention provides a high quality thin film comparable to a bulk single crystal and providres a semiconductor device with superior characteristics. A channel layer 11, for example, is formed of a semiconductor such as zinc oxide ZnO or the like. A source 12, a drain 13, a gate 14 and a gate insulating layer 15 are formed on the channel layer 111 to form an FET. For a substrate 16, a proper material is selected depending on a thin film material of the channel layer 11 in consideration of compatibility of both lattice constants. For example, if ZnO is used for the semiconductor of the channel layer as a base material, ScAlMgO4 or the like can be used for the substrate 16.

An edge emitting solid state laser and method. The laser comprises at least one AlInGaN active layer on a bulk GaN substrate with a non-polar or semi-polar orientation. The edges of the laser comprise {1 1−2±6} facets. The laser has high gain, low threshold currents, capability for extended operation at high current densities, and can be manufactured with improved yield. The laser is useful for optical data storage, projection displays, and as a source for general illumination.

The object of this invention is to provide a high-output type nitride semiconductor laser device comprising a pair of end faces of a resonator. The nitride semiconductor laser device comprises an n-type nitride semiconductor layer or layers, a p-type nitride semiconductor layer or layers and a resonator, provided with an active layer comprising nitride semiconductor containing In therebetween, wherein at least light emitting end face of the resonator is covered with an end face film of single crystal AlxGa1-xN (0<=x<=1) formed at a low temperature not causing damage to the active layer comprising nitride semiconductor containing In.

A semiconductor device has: a buffer layer formed on a conductive substrate and made of AlxGa1-xN with a high resistance; an element-forming layer formed on the buffer layer, having a channel layer, and made of undoped GaN and N-type AlyGa1-yN; and a source electrode, a drain electrode and a gate electrode which are selectively formed on the element-forming layer. The source electrode is filled in a through hole provided in the buffer layer and the element-forming layer, and is thus electrically connected to the conductive substrate.

A substrate is made of SiC. A plurality of AlxGa1-xN patterns (0<=x<=1) is formed on a surface of the substrate and dispersively distributed in an in-plane of the substrate. An AlyGa1-yN buffer layer (0<=y<=1) covers the surface of the substrate and the AlxGa1-xN patterns. A laser structure is formed on the AlyGa1-yN buffer layer. Since the AlGaN buffer layer is grown by using the AlGaN patterns as seed crystals, a dislocation density of a predetermined region in the AlGaN buffer layer can be lowered. The characteristics of a laser structure can be improved by forming the laser structure above the region having a low dislocation density. Since the AlGaN pattern has electric conductivity, the device resistance can be suppressed from being increased.

A nitride semiconductor device according to the present invention includes a p-type nitride semiconductor layer, an n-type nitride semiconductor layer, and an active layer interposed between the p-type nitride semiconductor layer and the n-type nitride semiconductor layer. The p-type nitride semiconductor layer includes: a first p-type nitride semiconductor layer containing Al and Mg; and a second p-type nitride semiconductor layer containing Mg. The first p-type nitride semiconductor layer is located between the active layer and the second p-type nitride semiconductor layer, and the second p-type nitride semiconductor layer has a greater band gap than a band gap of the first p-type nitride semiconductor layer.