Abstract: A p-type GaN guiding layer, an n-type GaN layer, and an n-type AlGaN current blocking layer are sequentially formed over an active layer, and then part of the current blocking layer is etched by using an alkali solution and irradiating the part with light to form an opening. Thereafter, a second p-type GaN guiding layer is formed on the current blocking layer to cover the opening. In this structure, the GaN layer has a smaller energy gap than the AlGaN current blocking layer.

Abstract: A gallium nitride-based device has a first GaN layer and a type II quantum well active region over the GaN layer. The type II quantum well active region comprises at least one InGaN layer and at least one GaNAs layer, wherein the InGaN comprises a graded molar In concentration.

Abstract: A buried semiconductor laser exhibiting a reduced dislocation of a contact layer is achieved. A buried semiconductor laser, comprising: an n-type indium phosphide (InP) substrate; an active layer disposed on the n-type InP substrate; block layers provided so as to bilaterally disposed on both sides of the active layer; a clad layer provided so as to cover the active layer and the block layers; and a p-type gallium indium arsenide (InGaAs) contact layer provided on the clad layer, wherein the p-type InGaAs contact layer has a compressive strain.

Abstract: A semiconductor device comprises an active layer and a cladding layer. An electron blocking layer is at least partially disposed in a region between the active layer and the cladding layer and is configured to form a potential barrier to a flow of electrons from the active layer toward the cladding layer. The electron blocking layer comprises two elements from Group III of the periodic table and an element from Group V of the periodic table. One of the two elements from Group III of the periodic table has a concentration profile with a first portion that gradually increases in concentration in a direction away from the active layer toward the cladding layer and a second portion that gradually decreases in concentration between the first portion and the cladding layer.

Abstract: Exemplary embodiments provide MQW semiconductor devices and methods for their manufacture. The MQW semiconductor devices can be formed by growing a MQW active region over a nanoscale periodic strain array. By using the nanoscale periodic strain array, the position, size, and composition of the In-rich clusters in the MQW active region can be controlled. This control of In-rich clusters can result in tighter wavelength control, which can be important for applications, such as, for example, lasers and LEDs.

Abstract: Methods and systems produce flattening layers associated with nitrogen-containing quantum wells and prevent 3-D growth of nitrogen containing layers using high As fluxes. MEE (Migration Enhanced Epitaxy) is used to flatten layers and enhance smoothness of quantum well interfaces and to achieve narrowing of the spectrum of light emitted from nitrogen containing quantum wells. MEE is performed by alternately depositing single atomic layers of group III and V before, and/or after, and/or in-between quantum wells. Where GaAs is used, the process can be accomplished by alternately opening and closing Ga and As shutters in an MBE system, while preventing both from being open at the same time. Where nitrogen is used, the system incorporates a mechanical means of preventing nitrogen from entering the MBE processing chamber, such as a gate valve.

Abstract: A semiconductor laser using a nitride type Group III-V compound semiconductor includes: an n-side clad layer; an n-side optical waveguide layer over the n-side clad layer; an active layer over the n-side optical waveguide layer; a p-side optical waveguide layer over the active layer; an electron barrier layer over the p-side optical waveguide layer; and a p-side clad layer over the electron barrier layer. A ridge stripe is formed at an upper part of the p-side optical waveguide layer, the electron barrier layer and the p-side clad layer, and the distance between the electron barrier layer and a bottom surface in areas on both sides of the ridge stripe is not less than 10 nm.

Abstract: A method for fabricating a laser diode comprising providing a laser diode epitaxial structure and depositing a metal layer stack on the epitaxial structure, the stack comprising a contact and sacrificial layer. A ridge is formed in the laser diode epitaxial structure, the stack being the mask forming the ridge. An insulting layer is deposited over the ridge and at least a portion of the sacrificial layer is removed. At least a portion of the insulating thin film at the top of the stack is also removed. A pad metal is deposited in electrical contact with the contact and the pad metal is insulated from the ridge and laser diode epitaxial structures by the insulting layer. A laser diode fabricated using the method comprises a laser diode epitaxial structure having a ridge with mesas on the sides of the ridge. A p-contact is on the ridge, and an insulating layer covers the exposed surfaces of the ridge, and at least a portion of the mesas.

Abstract: A laser diode comprising a first separate confinement heterostructure and an active region on the first separate confinement heterostructure. A second separate confinement heterostructure is on the active region and one or more epitaxial layers is on the second separate confinement heterostructure. A ridge is formed in the epitaxial layers with a first mesa around the ridge. The first mesa is 0.1 to 0.2 microns above the second confinement heterostructure.

Abstract: A laser diode and method for fabricating same, wherein the laser diode generally comprises an InGaN compliance layer on a GaN n-type contact layer and an AlGaN/GaN n-type strained super lattice (SLS) on the compliance layer. An n-type GaN separate confinement heterostructure (SCH) is on said n-type SLS and an InGaN multiple quantum well (MQW) active region is on the n-type SCH. A GaN p-type SCH on the MQW active region, an AlGaN/GaN p-type SLS is on the p-type SCH, and a p-type GaN contact layer is on the p-type SLS. The compliance layer has an In percentage that reduces strain between the n-type contact layer and the n-type SLS compared to a laser diode without the compliance layer. Accordingly, the n-type SLS can be grown with an increased Al percentage to increase the index of refraction. This along with other features allows for reduced threshold current and voltage operation.

Abstract: In a semiconductor laser element, a lower cladding layer of AlGaInP of the first conductive type, a lower optical waveguide layer of AlGaInP, a quantum-well active layer of InGaP, an upper optical waveguide layer of AlGaInP, and an upper cladding layer of AlGaInP of the second conductive type are formed in this order on a substrate of GaAs of the first conductive type. The degree of mismatch ?a/a with the substrate and the thickness dw of the quantum-well active layer satisfy the conditions, ?0.6%??a/a??0.3% and 10 nm?dw?20 nm. In addition, the resonator length Lc and the reflectances Rf and Rr of the opposite end facets satisfy the conditions, Lc?400 ?m and Rf×Rr?0.5.

Abstract: The invention is a photonic crystal laser including a photonic crystal slab laser cavity including InGaP/InGaAlP crystalline layers, the InGaP/InGaAlP crystalline layers having a relaxed strain at one or more etched surfaces and a higher strain at a plurality of quantum wells and at a distance from the one or more etched surfaces. The photonic crystal laser also includes electrical pads configured to receive an electrical signal the electrical pads attached to the photonic crystal slab laser cavity via an insulating layer, the photonic crystal laser configured to emit a laser light in response to the electrical signal. In another aspect, the invention features a photonic crystal detector including a photonic crystal slab cavity including InGaP/InGaAlP crystalline layers. In yet another aspect, the invention features a process to fabricate a photonic crystal laser cavity.

Abstract: A first and second semiconductor laser, which comprise buffer layers, cladding layers, quantum well active layers, and cladding layers integrated on the substrate and have a stripe geometry, are integrated on a common substrate, with the quantum well active layers in the vicinity of the cavity facets disordered by impurity diffusion. Relationships ?1>?b1, ?2>?b2, ?1>?2, and E1?E2 are satisfied, where ?1 and ?2 are defined, respectively, as the emission wavelengths of the active layers of the first and second semiconductor lasers, E1 and E2, respectively, as the forbidden band energies of the buffer layers of the first and second semiconductor lasers, and ?b1 and ?b2 respectively as the wavelengths corresponding to the forbidden band energies of the buffer layers of the first and second semiconductor lasers.

Abstract: A method of fabricating a nitride-based semiconductor device capable of reducing contact resistance between a nitrogen face of a nitride-based semiconductor substrate or the like and an electrode is provided. This method of fabricating a nitride-based semiconductor device comprises steps of etching the back surface of a first semiconductor layer consisting of either an n-type nitride-based semiconductor layer or a nitride-based semiconductor substrate having a wurtzite structure and thereafter forming an n-side electrode on the etched back surface of the first semiconductor layer.

Abstract: The present invention provides a Be-based group II-VI semiconductor laser using an InP substrate and having a stacked structure capable of continuous oscillation at a room temperature. A basic structure of a semiconductor laser is constituted by using a Be-containing lattice-matched II-VI semiconductor above an InP substrate. An active laser, an optical guide layer, and a cladding layer are constituted in a double hetero structure having a type I band line-up in order to enhance the injection efficiency of carriers to the active layer. Also, the active layer, the optical guide layer, and the cladding layer, which are capable of enhancing the optical confinement to the active layer, are constituted, and the cladding layer is constituted with bulk crystals.

Abstract: It is an object of the present invention to provide a semiconductor laser device with high-yielding in which a clack generated in an epitaxial growth layer is restrained and to the manufacturing method thereof, the semiconductor laser device includes a GaN substrate 1, an n-type GaN layer 2, an n-type AlGaN cladding layer 3, a n-type GaN guide layer 4, an InGaN multiple quantum well active layer 5, an undoped-GaN guide layer 6, a p-type AlGaN electron overflow suppression layer 7, a p-type GaN guide layer 8, a SiO2 blocking layer 9, an Ni/ITO cladding layer electrode 10 as a transparent electrode, a Ti/Au pad electrode 11, and a Ti/Al/Ni/Au electrode 12. The SiO2 blocking layer 9 is formed above the InGaN multiple quantum well active layer 5 so as to have an opening. The Ni/ITO cladding layer electrode 10 is formed inside the opening, and which is transparent for the light from the InGaN multiple quantum well active layer, and serves as a cladding layer.

Abstract: An active layer of a laser diode comprises: a plurality of quantum well layers; a plurality of quantum barrier layers formed between the quantum well layers; and a plurality of tensile-stressed GaInP layers formed between the quantum barrier layers, whereby the lateral flow of electron-hole pairs in the active layer can be blocked so as to prevent the recombination of the electron-hole pairs in the quantum barrier layers of the laser diode for reducing the carrier current leakage and preventing the tensile-stressed GaInP layers from compensating the compressive-stressed quantum well layers so as to maintain the compressive stress of the quantum well layers.

Abstract: In a semiconductor optical device, the semiconductor substrate has a primary surface intersecting with a predetermined axis. The lower cladding region of the first conductive type is provided on the primary surface thereof. The lower cladding region includes ridge regions and a base region. The base region has first portions and second portions. The first portions and the second portions are alternately arranged along a predetermined plane perpendicular to the predetermined axis. Each first portion extends in an optical propagating direction. Each second portion extends in the optical propagating direction. Each ridge region is located on each second portion. Each ridge region has a side and a top, and each first portion has a top. The upper cladding layer of the second conductive type is provided on the primary surface of the semiconductor substrate. The bulk active layer is provided between the upper cladding layer and the lower cladding region.

Abstract: In a semiconductor laser element: a lower cladding layer of In0.49(Alx1Ga1-x1)0.51(x2<x1<1) of a first conductive type which lattice-matches with GaAs; a lower optical waveguide layer of In0.49(Alx2Ga1-x2)0.51P (0<x2<x1) which lattice-matches with GaAs; an active layer; an upper optical waveguide layer of In0.49(Alx2Ga1-x2)0.51P (0<x2<x1) which lattice-matches with GaAs; and an upper cladding layer of In0.49(Alx1Ga1-x1)0.51P (x2<x1<1) of a second conductive type which lattice-matches with GaAs are formed in this order on a substrate of GaAs. The total thickness of the lower optical waveguide layer, the active layer, and the upper optical waveguide layer is 0.30 micrometers or greater.

Abstract: An electronic or optoelectronic device fabricated from a crystalline material in which a parameter of a bandgap characteristic of said crystalline material has been modified locally by introducing distortions on an atomic scale in the lattice structure of said crystalline material and the electronic and/or optoelectronic parameters of said device are dependent on the modification of said bandgap is exemplified by a radiation emissive optoelectronic semiconductor device which comprises a junction (10) formed from a p-type layer (11) and an n-type layer (12), both formed from indirect bandgap semiconductor material. The p-type layer (11) contains a array of dislocation loops which create a strain field to confine spatially and promote radiative recombination of the charge carriers.

Abstract: In accordance with the present invention, GaAs-based optoelectronic devices have an active region that includes a well layer composed of a compressively-strained semiconductor that is free, or substantially free, of nitrogen disposed between two barrier layers composed of a nitrogen- and indium-containing semiconductor.

Abstract: A mid-infrared emitting indirect bandgap quantum well semiconductor laser with an optical waveguide structure having an active waveguide core. The active waveguide core comprises at least one repetition of a sub-region comprising in the following order a first wide bandgap layer, a first conduction band layer of InAs, a valence band layer of Ga(1-x)InxSb where x?0.7, preferably of InSB (ie. x=1), having a thickness of less than 15 Angstroms, a second conduction band layer of InAs and a second wide bandgap barrier layer. The barrier layers co-operate to provide electrical confinement for the carriers within the intervening conduction band and valence band layers and optical confinement in the active core region is provided by the optical waveguide structure.

Abstract: A semiconductor laser device has a multilayer structure including a first clad layer, an active layer, and a second clad layer stacked successively on a semiconductor substrate in order of increasing distance from the semiconductor substrate. At least one of the first clad layer and the second clad layer has a compressive distortion with respect to the semiconductor substrate. At least one of the first clad layer and the second clad layer includes a semiconductor layer having a tensile distortion with respect to the semiconductor substrate.

Abstract: In a constitution where a first clad layer is formed on a semiconductor substrate, an active layer having the strained multiple quantum well structure is formed on the first clad layer, and a second clad layer is formed on the active layer, the sum of products of strain amounts and film thickness in the active layer is set to a negative value

Abstract: A method for producing a semiconductor entity is described. The method includes providing a donor substrate having a zone of weakness at a predetermined depth to define a thin layer, and the donor substrate includes a bonding interface. A receiver substrate is also provided that includes at least one motif on its surface. The technique further includes bonding the donor substrate at the bonding interface to the at least one motif on the receiver substrate, and supplying sufficient energy to detach a portion of the thin layer from the donor substrate located at the at least one motif and to rupture bonds within the thin layer. The energy thus supplied is insufficient to rupture the bond at the bonding interface. Also described is fabrication of a wafer and the use of the method to produce chips suitable for use in electronics, optics, or optoelectronics applications.

Abstract: A 780 nm band semiconductor laser device has an InGaAsP well layer, phosphorous composition of which is 0.51 smaller than 0.55 to prevent spinodal decomposition in growing InGaAsP. A compressive strain of 0.65% less than 1% and more than 0.25% is introduced into the well layer to reduce threshold current thereof. Thus, the 0.78-?m band semiconductor laser device having the InGaAsP well layer stably operates for a long time even in outputting a high optical power of 100 mW or more. A tensile strain of 1.2% is also introduced into barrier layers within the active region so as to compensate the stress due to the compressive strain of the well layer. As a result, the reliability of the semiconductor laser device is further increased during a high output operation.

Abstract: A graded SiGe buffer layer 12 and a SiGe buffer layer 13 are formed on a Si substrate 11. A strained Si layer 14 having a critical film thickness or less is formed to decrease a stress applied to an interface between the strained Si layer 14 and the SiGe buffer layer 13, thereby obtaining a strained Si layer 14, in which a crystal defect density is low. Furthermore, the surface of the strained Si layer 14 is covered by a SiGe cap layer 21, which has a lattice constant greater than Si, thereby preventing the strained Si layer 14 from disappearing due to the sacrifice oxidation performed in the later steps, and enabling a gate oxide layer to be formed thereon. Thus, it is possible to obtain a high-quality strained Si wafer.

Abstract: A semiconductor laser diode using the aluminum gallium, arsenide, gallium indium arsenide phosphide, indium phosphide, (AlGaInAs/GaInAsP/InP) material system and related combinations is disclosed. Both the design of the active layer and the design of the optical cavity are optimized to minimize the temperature rise of the active region and to minimize the effects of elevated active layer temperature on the laser efficiency. The result is a high output power semiconductor laser for the wavelengths between 1.30 and 1.61 micrometers for the pumping of erbium doped waveguide devices or for direct use in military, medical, or commercial applications.

Abstract: A vertical cavity surface emitting laser (VCSEL) includes an indium-based semiconductor alloy substrate, a first mirror stack over the substrate, an active region having a plurality of quantum wells over the first mirror stack, a tunnel junction over the active region, the tunnel junction including a p-doped pseudomorphically strained layer of a compound selected from the group consisting of Al-rich InAlAs, AlAs, Ga-rich InGaAs, GaAs and combinations thereof, and a second mirror stack over the tunnel junction. The pseudomorphically strained layer can be used to form a tunnel junction with a n-doped layer of InP or AlInAs, or with a lower bandgap material such as AlInGaAs or InGaAsP. Such tunnel junctions are especially useful for a long wavelength VCSEL.

Abstract: A semiconductor laser device is one of AlGaInAs semiconductor laser devices, and has a multi-layer structure with a n-GaAs substrate on which a n-Al0.3Ga0.7As buffer layer, a n-Al0.47Ga0.53As clad layer, active layer portion, p-Al0.47Ga0.53As clad layer and p-GaAs cap layer are formed. The active layer portion is configured as a multi-layer structure including (Al0.37Ga0.63)0.97In0.03As light guide layer, Al0.1Ga0.9As active layer and (Al0.37Ga0.63)0.97In0.03As light guide layer. By using the AlGaInAs layer to which In is added is used as the light guide layers, the active layer is under compressive strain. Accordingly, the lattice constant of the active layer at the laser emitting edge becomes smaller due to a force from the adjacent light guide layers. The band gap energy of the active layer near the laser emitting edge becomes larger than the inside of laser device, thereby forming the window structure.

Abstract: In a semiconductor optical device, the semiconductor substrate has a primary surface intersecting with a predetermined axis. The lower cladding region of the first conductive type is provided on the primary surface thereof. The lower cladding region includes ridge regions and a base region. The base region has first portions and second portions. The first portions and the second portions are alternately arranged along a predetermined plane perpendicular to the predetermined axis. Each first portion extends in an optical propagating direction. Each second portion extends in the optical propagating direction. Each ridge region is located on each second portion. Each ridge region has a side and a top, and each first portion has a top. The upper cladding layer of the second conductive type is provided on the primary surface of the semiconductor substrate. The bulk active layer is provided between the upper cladding layer and the lower cladding region.

Abstract: Quantum wells and associated barriers layers can be grown to include nitrogen (N), aluminum (Al), antimony (Sb), phosphorous (P) and/or indium (In) placed within or about a typical GaAs substrate to achieve long wavelength VCSEL performance, e.g., within the 1260 to 1650 nm range. In accordance with features of the present invention, a vertical cavity surface emitting laser (VCSEL) can include at least one quantum well comprised of InGaAsSbN; barrier layers sandwiching said at least one quantum well; and confinement layers sandwiching said barrier layers. Confinement and barrier layers can comprise AlGaAs. Barrier layer, in the alternative, can also comprise GaAsP. Nitrogen can be placed in the quantum wells. Quantum wells can be developed up to and including 50 ? in thickness. Quantum wells can also be developed with a depth of at least 40 meV.

Abstract: The invention relates to high power semiconductor diode lasers of the type commonly used in opto-electronics, mostly as so-called pump lasers for fiber amplifiers in the field of optical communication, e.g. for an erbium-doped fiber amplifier (EDFA) or a Raman amplifier. Such a laser, having a single cavity and working in single transverse mode, is improved by placing a multilayer large optical superlattice structure (LOSL) into at least one of the provided cladding layers. This LOSL provides for a significantly improved shape of the exit beam allowing an efficient high power coupling into the fiber of an opto-electronic network.

Abstract: The present invention provides a technology for increasing the spectral width of semiconductor optical amplifiers, employing different separate confinement heterostructures (SCH's) so as to form non-identical multiple quantum wells such that the semiconductor photo-electronic devices have better temperature characteristics and more reliable modulation characteristics. If such a technology is used in the fabrication of semiconductor laser with a tunable wavelength, it is possible to achieve a large range of modulated wavelength, which is very useful in optical communication.

Abstract: In a semiconductor optical modulator of this invention, each quantum-well layer and each barrier layer of a quantum-well structure serving as a light absorption layer are respectively made of In1-X-YGaXAlYN (0?X, Y?1, 0?X+Y?1) and In1-X?-Y?GaX?AlY?N (0?X?, Y??1, 0?X?+Y??1). An electric field is being generated in the light absorption layer by spontaneous polarization.

Abstract: A laser diode capable of inhibiting overflow of electrons in a p-type cladding layer and improving temperature characteristics and light emitting efficiency is provided. A laser diode at least comprises: an n-type cladding layer; an active layer; and a p-type cladding layer, which are made of an AlGaInP compound semiconductor material and formed in this order on a substrate. A thickness of the p-type cladding layer is 0.7 ?m or less.

Abstract: Several methods are used in novel ways with newly identified and viable parameters to decrease the peak transition energies of the pseudomorphic InGaAs/GaAs heterostructures. These techniques, taken separately or in combination, suffice to permit operation of light emitting devices at wavelengths of 1.3 ?m or greater of light-emitting electro-optic devices. These methods or techniques, by example, include: (1) utilizing new superlattice structures having high In concentrations in the active region, (2) utilizing strain compensation to increase the usable layer thickness for quantum wells with appropriately high In concentrations, (3) utilizing appropriately small amounts of nitrogen (N) in the pseudomorphic InGaAsN/GaAs laser structure, and (4) use of nominal (111) oriented substrates to increase the usable layer thickness for quantum wells with appropriately high In concentrations.

Abstract: A quantum cascade laser structure in accordance with the invention comprises a number of cascades (100), each of which comprises a number of alternately arranged quantum wells (110a to 110j) and barrier layers (105 to 105j). The material of at least one quantum well (110a to 110j) as well as the material of at least one barrier layer (105 to 105j) is under mechanical strain, with the respective strain being either a tensile strain or a compression strain. The quantum wells (110a to 110j) and barrier layers (105 to 105j) are engineered in the quantum cascade laser structure in accordance with the invention so that existing strains are largely compensated within a cascade (100). In the quantum cascade laser structure in accordance with the invention, each material of the quantum wells (110a to 110j) has only one constituent material and the material of at least one barrier layer (105d, 105e, 105f) has at least two constituent materials (111a, 111b, 112a, 112b, 113a, 113b).