Abstract: A method of forming a kilometer(s)-length high temperature superconductor tape by feeding a textured tape from roll-to-roll through a reactor chamber, flowing high temperature superconductor precursors from an elongated precursor showerhead positioned in the chamber the elongation in a direction along the tape; flowing gas from first and second elongated gas curtain shower heads on either side of the precursor showerhead; and illuminating the upper surface of the tape with illumination from sources on opposing sides of the reactor, the illumination sources positioned so as to allow illumination to pass under a respective one of the curtain shower heads and under the precursor showerhead to the upper surface of the tape.

Abstract: Group III nitride-based laser diodes comprise an n-side cladding layer formed of n-doped (Al,In)GaN, an n-side waveguide layer formed of n-doped (Al)InGaN, an active region, a p-side waveguide layer formed of p-doped (Al)InGaN, and a p-side cladding layer formed of p-doped (Al,In)GaN. Optical mode is shifted away from high acceptor concentrations in p-type layers through manipulation of indium concentration and thickness of the n-side waveguide layer. Dopant and compositional profiles of the p-side cladding layer and the p-side waveguide layer are tailored to reduce optical loss and increased wall plug efficiency.

Abstract: An embodiment of semiconductor laser comprising: (a) a GaN, AlGaN, InGaN, or AlN substrate; (b) an n-doped cladding layer situated over the substrate; (c) a p-doped cladding layer situated over the n-doped; (d) at least one active layer situated between the n-doped and the p-doped cladding layer, and at least one of said cladding layers comprises a superstructure structure of AlInGaN/GaN, AlInGaN/AlGaN, AlInGaN//InGaN or AlInGaN/AlN with the composition such that the total of lattice mismatch strain of the whole structure does not exceed 40 nm %.

Abstract: Laser diodes and methods of fabricating laser diodes are disclosed. A laser diode includes a substrate including (Al,In)GaN, an n-side cladding layer including (Al,In)GaN having an n-type conductivity, an n-side waveguide layer including (Al,In)GaN having an n-type conductivity, an active region, a p-side waveguide layer including (Al,In)GaN having a p-type conductivity, a p-side cladding layer including (Al,In)GaN having a p-type conductivity, and a laser cavity formed by cleaved facets. The substrate includes a crystal structure having a surface plane orientation within about 10 degrees of a 20 23 or a 20 23 crystallographic plane orientation. The laser cavity is formed by cleaved facets that have an orientation corresponding to a nonpolar plane of the crystal structure of the substrate.

Abstract: Light emitting devices are provided comprising an active region interposed between n-type and p-type sides of the device and a hole blocking layer interposed between the active region and the n-type side of the device. The active region comprises an active MQW structure and is configured for electrically-pumped stimulated emission of photons in the green portion of the optical spectrum. The n-type side of the light emitting device comprises an n-doped semiconductor region. The p-type side of the light emitting device comprises a p-doped semiconductor region. The n-doped semiconductor region comprises an n-doped non-polar or n-doped semi-polar substrate. Hole blocking layers according to the present disclosure comprise an n-doped semiconductor material and are interposed between the non-polar or semi-polar substrate and the active region of the light emitting device. The hole blocking layer (HBL) composition is characterized by a wider bandgap than that of the quantum well barrier layers of the active region.

Abstract: Light emitting devices are provided comprising an active region interposed between n-type and p-type sides of the device and a hole blocking layer interposed between the active region and the n-type side of the device. The active region comprises an active MQW structure and is configured for electrically-pumped stimulated emission of photons in the green portion of the optical spectrum. The n-type side of the light emitting device comprises an n-doped semiconductor region. The p-type side of the light emitting device comprises a p-doped semiconductor region. The n-doped semiconductor region comprises an n-doped non-polar or n-doped semi-polar substrate. Hole blocking layers according to the present disclosure comprise an n-doped semiconductor material and are interposed between the non-polar or semi-polar substrate and the active region of the light emitting device. The hole blocking layer (HBL) composition is characterized by a wider bandgap than that of the quantum well barrier layers of the active region.

Abstract: According to the concepts of the present disclosure, laser diode waveguide configurations are contemplated where the use of Al in the waveguide layers of the laser is presented in the form of InGaN/Al(In)GaN waveguiding superstructure comprising optical confining wells (InGaN) and strain compensating barriers (Al(In)GaN). The composition of the optical confining wells is chosen such that they provide strong optical confinement, even in the presence of the Al(In)GaN strain compensating barriers, but do not absorb lasing emission. The composition of the strain compensating barriers is chosen such that the Al(In)GaN exhibits tensile strain that compensates for the compressive strain of InGaN optical confinement wells but does not hinder the optical confinement.

Abstract: A GaN edge emitting laser is provided comprising a semi-polar GaN substrate, an active region, N-side and P-side waveguiding layers, and N-type and P-type cladding layers. The GaN substrate defines a 20 21 crystal growth plane and a glide plane. The N-side and P-side waveguiding layers comprise a GaInN/GaN or GaInN/GaInN superlattice (SL) waveguiding layers. The SL layers of the N-side and P-side SL waveguiding layers have layer thicknesses between approximately 1 nm and 5 nm that are optimized for waveguide planarity. In another embodiments, planarization is enhanced by ensuring that the N-side and P-side GaN-based waveguiding layers are grown at a growth rate that exceeds approximately 0.09 nm/s, regardless of whether the N-side and P-side GaN-based waveguiding layers are provided as a GaInN/GaN SL, GaInN/GaInN SL or as bulk layers. In further embodiments, planarization is enhanced by selecting optimal SL layer thicknesses and growth rates.

Abstract: A method of manufacturing an optoelectronic light emitting semiconductor device is provided where a Multi-quantum Well (MQW) subassembly is subjected to reduced temperature vapor deposition processing to form one or more of n-type or p-type layers over the MQW subassembly utilizing a plurality of precursors and an indium surfactant. The precursors and the indium surfactant are introduced into the vapor deposition process at respective flow rates with the aid of one or more carrier gases, at least one of which comprises H2. The indium surfactant comprises an amount of indium sufficient to improve crystal quality of the p-type layers formed during the reduced temperature vapor deposition processing and the respective precursor flow rates and the H2 content of the carrier gas are selected to maintain a mole fraction of indium from the indium surfactant to be less than approximately 1% in the n-type or p-type layers.

Abstract: Methods and apparatus for producing a gallium nitride semiconductor on insulator structure include: bonding a single crystal silicon layer to a transparent substrate; and growing a single crystal gallium nitride layer on the single crystal silicon layer.

Abstract: A GaN edge emitting laser is provided comprising a semi-polar GaN substrate, an active region, N-side and P-side waveguiding layers, and N-type and P-type cladding layers. The GaN substrate defines a 20 21 crystal growth plane and a glide plane. The N-side and P-side waveguiding layers comprise a GaInN/GaN or GaInN/GaInN superlattice (SL) waveguiding layers. The SL layers of the N-side and P-side SL waveguiding layers have layer thicknesses between approximately 1 nm and 5 nm that are optimized for waveguide planarity. In another embodiments, planarization is enhanced by ensuring that the N-side and P-side GaN-based waveguiding layers are grown at a growth rate that exceeds approximately 0.09 nm/s, regardless of whether the N-side and P-side GaN-based waveguiding layers are provided as a GaInN/GaN SL, GaInN/GaInN SL or as bulk layers. In further embodiments, planarization is enhanced by selecting optimal SL layer thicknesses and growth rates.

Abstract: According to the concepts of the present disclosure, laser diode waveguide configurations are contemplated where the use of Al in the waveguide layers of the laser is presented in the form of InGaN/Al(In)GaN waveguiding superstructure comprising optical confining wells (InGaN) and strain compensating barriers (Al(In)GaN). The composition of the optical confining wells is chosen such that they provide strong optical confinement, even in the presence of the Al(In)GaN strain compensating barriers, but do not absorb lasing emission. The composition of the strain compensating barriers is chosen such that the Al(In)GaN exhibits tensile strain that compensates for the compressive strain of InGaN optical confinement wells but does not hinder the optical confinement.

Abstract: Methods and apparatus for producing a gallium nitride semiconductor on insulator structure include: bonding a single crystal silicon layer to a transparent substrate; and growing a single crystal gallium nitride layer on the single crystal silicon layer.

Abstract: A GaN edge emitting laser is provided comprising a semi-polar GaN substrate, an active region, an N-side waveguiding layer, a P-side waveguiding layer, an N-type cladding layer, and a P-type cladding layer. The GaN substrate defines a 20 21 crystal growth plane and a glide plane. The N-side and P-side waveguiding layers comprise a GaInN/GaN or GaInN/GaInN superlattice (SL) waveguiding layers. The superlattice layers of the N-side and P-side SL waveguiding layers define respective layer thicknesses that are optimized for waveguide planarity, the layer thicknesses being between approximately 1 nm and approximately 5 nm. In accordance with another embodiment of the present disclosure, planarization can be enhanced by ensuring that the N-side and P-side GaN-based waveguiding layers are grown at a growth rate that exceeds approximately 0.09 nm/s, regardless of whether the N-side and P-side GaN-based waveguiding layers are provided as a GaInN/GaN or GaInN/GaInN SL or as bulk waveguiding layers.

Abstract: A GaN-based edge emitting laser is provided comprising a semi-polar GaN substrate, an active region, an N-side waveguiding layer, a P-side waveguiding layer, an N-type cladding layer, and a P-type cladding layer. The GaN substrate is characterized by a threading dislocation density on the order of approximately 1×106/cm2. The strain-thickness product of the N-side waveguiding layer exceeds its strain relaxation critical value. In addition, the cumulative strain-thickness product of the active region calculated for the growth on a the relaxed N-side waveguiding layer is less than its strain relaxation critical value. As a result, the N-side interface between the N-type cladding layer and the N-side waveguiding layer comprises a set of N-side misfit dislocations and the P-side interface between the P-type cladding layer and the P-side waveguiding layer comprises a set of P-side misfit dislocations. Additional embodiments are disclosed and claimed.

Abstract: Group III nitride-based laser diodes comprise an n-side cladding layer formed of n-doped (Al,In)GaN, an n-side waveguide layer formed of n-doped (Al)InGaN, an active region, a p-side waveguide layer formed of p-doped (Al)InGaN, and a p-side cladding layer formed of p-doped (Al,In)GaN. Optical mode is shifted away from high acceptor concentrations in p-type layers through manipulation of indium concentration and thickness of the n-side waveguide layer. Dopant and compositional profiles of the p-side cladding layer and the p-side waveguide layer are tailored to reduce optical loss and increased wall plug efficiency.

Abstract: Multi-quantum well laser structures are provided comprising active and/or passive MQW regions. Each of the MQW regions comprises a plurality of quantum wells and intervening barrier layers. Adjacent MQW regions are separated by a spacer layer that is thicker than the intervening barrier layers. The bandgap of the quantum wells is lower than the bandgap of the intervening barrier layers and the spacer layer. The active region may comprise active and passive MQWs and be configured for electrically-pumped stimulated emission of photons or it may comprises active MQW regions configured for optically-pumped stimulated emission of photons.

Abstract: A GaN edge emitting laser is provided comprising a semi-polar GaN substrate, an active region, an N-side waveguiding layer, a P-side waveguiding layer, an N-type cladding layer, and a P-type cladding layer. The GaN substrate defines a 20 21 crystal growth plane and a glide plane. The N-side and P-side waveguiding layers comprise a GaInN/GaN or GaInN/GaInN superlattice (SL) waveguiding layers. The superlattice layers of the N-side and P-side SL waveguiding layers define respective layer thicknesses that are optimized for waveguide planarity, the layer thicknesses being between approximately 1 nm and approximately 5 nm. In accordance with another embodiment of the present disclosure, planarization can be enhanced by ensuring that the N-side and P-side GaN-based waveguiding layers are grown at a growth rate that exceeds approximately 0.09 nm/s, regardless of whether the N-side and P-side GaN-based waveguiding layers are provided as a GaInN/GaN or GaInN/GaInN SL or as bulk waveguiding layers.

Abstract: A GaN-based edge emitting laser is provided comprising a semi-polar GaN substrate, an active region, an N-side waveguiding layer, a P-side waveguiding layer, an N-type cladding layer, and a P-type cladding layer. The GaN substrate is characterized by a threading dislocation density on the order of approximately 1×106/cm2. The strain-thickness product of the N-side waveguiding layer exceeds its strain relaxation critical value. In addition, the cumulative strain-thickness product of the active region calculated for the growth on a the relaxed N-side waveguiding layer is less than its strain relaxation critical value. As a result, the N-side interface between the N-type cladding layer and the N-side waveguiding layer comprises a set of N-side misfit dislocations and the P-side interface between the P-type cladding layer and the P-side waveguiding layer comprises a set of P-side misfit dislocations. Additional embodiments are disclosed and claimed.

Abstract: Multi-quantum well laser structures are provided comprising active and/or passive MQW regions. Each of the MQW regions comprises a plurality of quantum wells and intervening barrier layers. Adjacent MQW regions are separated by a spacer layer that is thicker than the intervening barrier layers. The bandgap of the quantum wells is lower than the bandgap of the intervening barrier layers and the spacer layer. The active region may comprise active and passive MQWs and be configured for electrically-pumped stimulated emission of photons or it may comprises active MQW regions configured for optically-pumped stimulated emission of photons.