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: 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-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: Concepts of the present disclosure may be employed to optimize optical pumping and ensure high modal gain in the active region of an optically pumped laser source by establishing an optical coupling gap such that the pump waveguide mode field overlaps the active gain region associated with the signal waveguide. The optical coupling gap is tailored to be sufficiently large to ensure that a significant active gain region length is required for absorption and sufficiently small to ensure that the pump waveguide mode field P overlaps the active gain region. In accordance with one embodiment of the present disclosure, the pump waveguide core is displaced from the signal waveguide core by an optical coupling gap g in a lateral direction that is approximately perpendicular to the optical pumping axis.

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: 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 semiconductor laser device operable to emit light having a desired wavelength in the green spectral range. The semiconductor laser device may include a pumping source and a laser structure including a substrate, a first cladding layer, and one or more active region layers. The one or more active region layers include a number of quantum wells having a spontaneous emission peak wavelength that is greater than about 520 nm at a reference pumping power density. The pumping source is configured to pump each quantum well at a pumping power density such that a stimulated emission peak of each quantum well is within the green spectral range, and the number of quantum wells within the one or more active region layers is such that a net optical gain of the quantum wells is greater than a net optical loss coefficient at the desired wavelength in the green spectral range.

Abstract: A semiconductor laser device operable to emit light having a desired wavelength in the green spectral range. The semiconductor laser device may include a pumping source and a laser structure including a substrate, a first cladding layer, and one or more active region layers. The one or more active region layers include a number of quantum wells having a spontaneous emission peak wavelength that is greater than about 520 nm at a reference pumping power density. The pumping source is configured to pump each quantum well at a pumping power density such that a stimulated emission peak of each quantum well is within the green spectral range, and the number of quantum wells within the one or more active region layers is such that a net optical gain of the quantum wells is greater than a net optical loss coefficient at the desired wavelength in the green spectral range.

Abstract: An optoelectronic light emitting semiconductor device is provided comprising an active region, a p-type Group III nitride layer, an n-type Group III nitride layer, a p-side metal contact layer, an n-side metal contact layer, and an undoped tunneling enhancement layer. The p-side metal contact layer is characterized by a work function W satisfying the following relation: W?e?AFF±0.025 eV where e?AFF is the electron affinity of the undoped tunneling enhancement layer. The undoped tunneling enhancement layer and the p-type Group III nitride layer comprise conduction and valence energy bands. The top of the valence band V1 of the undoped tunneling enhancement layer is above the top of the valence band V2 of the p-type Group III nitride layer at the band offset interface to generate a capacity for a relatively high concentration of holes in the undoped tunneling enhancement layer at the band offset interface. 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.

Abstract: Ga(In)N-based laser structures and related methods of fabrication are proposed where Ga(In)N-based semiconductor laser structures are formed on AlN or GaN substrates in a manner that addresses the need to avoid undue tensile strain in the semiconductor structure. In accordance with one embodiment of the present invention, a Ga(In)N-based semiconductor laser is provided on an AlN or GaN substrate provided with an AlGaN lattice adjustment layer where the substrate, the lattice adjustment layer, the lower cladding region, the active waveguiding region, the upper cladding region, and the N and P type contact regions of the laser form a compositional continuum in the semiconductor laser. Additional embodiments are disclosed and claimed.

Abstract: Ga(In)N-based laser structures and related methods of fabrication are proposed where Ga(In)N-based semiconductor laser structures are formed on AlN or GaN substrates in a manner that addresses the need to avoid undue tensile strain in the semiconductor structure. In accordance with one embodiment of the present invention, a Ga(In)N-based semiconductor laser is provided on an AlN or GaN substrate provided with an AlGaN lattice adjustment layer where the substrate, the lattice adjustment layer, the lower cladding region, the active waveguiding region, the upper cladding region, and the N and P type contact regions of the laser form a compositional continuum in the semiconductor laser. Additional embodiments are disclosed and claimed.