Abstract: A distributed feedback structure includes a substrate material. An active layer has an alloy including at least one of aluminum, gallium, indium, and nitrogen. A first cladding, having an alloy including at least one of the aluminum, the gallium, the indium, and the nitrogen, is on a first side of the active layer. A second cladding, having an alloy including at least one of the aluminum, the gallium, the indium, and the nitrogen, is on a second side of the active layer. Periodic variations of refractive indices in at least one of the first and second claddings provide a distributed optical feedback.

Abstract: An index-guided buried heterostructure AlGaInN laser diode provides improved mode stability and low threshold current when compared to conventional ridge waveguide structures. A short period superlattice is used to allow adequate cladding layer thickness for confinement without cracking. The intensity of the light lost due to leakage is reduced by about 2 orders of magnitude with an accompanying improvement in the far-field radiation pattern when compared to conventional structures.

Abstract: A self aligned, index-guided, buried heterostructure AlGalnN laser diode provides improved mode stability and low threshold current when compared to conventional ridge waveguide structures. A short period superlattice is used to allow adequate cladding layer thickness for confinement without cracking. The intensity of the light lost due to leakage is reduced by about 2 orders of magnitude with an accompanying improvement in the far-field radiation pattern when compared to conventional structures. The comparatively large p-contact area allowed by the self-aligned architecture contributes to a lower diode voltage and less heat during continuous wave operation of the laser diode.

Abstract: A dual III-V nitride laser structure has a thick current spreading layer on a sapphire substrate and a trench extending into the current spreading layer to reduce thermal cross-talk between the dual lasers.

Abstract: A method for placing nitride laser diode arrays on a thermally and electrically conducting substrate is described. The method uses an excimer laser to detach the nitride laser diode from the sapphire growth substrate after an intermediate substrate has been attached to the side opposite the sapphire substrate. A secondary layer is subsequently deposited to act as a transfer support structure and bonding interface. The membrane is released from the intermediate substrate and a thermally conducting substrate is subsequently bonded to the side where the sapphire substrate was removed. Similarly, the secondary layer may be used as the new host substrate given an appropriate thickness is deposited prior to removal of the intermediate substrate.

Abstract: Substrates having increased thermal conductivity are provided, comprising a body having opposed surfaces and a cavity that opens on at least one surface, the cavity containing at least one material having a greater thermal conductivity than the body. Devices are provided comprising a substrate and a semiconductor over a surface of the substrate. Methods of forming devices according to the invention are also provided.

Abstract: A structure and method for an asymmetric waveguide nitride laser diode without need of a p-type waveguide is disclosed. The need for a high aluminum tunnel barrier layer in the laser is avoided.

Abstract: A self aligned, index-guided, buried heterostructure AlGaInN laser diode provides improved mode stability and low threshold current when compared to conventional ridge waveguide structures. A short period superlattice is used to allow adequate cladding layer thickness for confinement without cracking. The intensity of the light lost due to leakage is reduced by about 2 orders of magnitude with an accompanying improvement in the far-field radiation pattern when compared to conventional structures. The comparatively large p-contact area allowed by the self-aligned architecture contributes to a lower diode voltage and less heat during continuous wave operation of the laser diode.

Abstract: An index-guided buried heterostructure AlGaInN laser diode provides improved mode stability and low threshold current when compared to conventional ridge waveguide structures. A short period superlattice is used to allow adequate cladding layer thickness for confinement without cracking. The intensity of the light lost due to leakage is reduced by about 2 orders of magnitude with an accompanying improvement in the far-field radiation pattern when compared to conventional structures.

Abstract: A III-V nitride blue laser diode has an amplifier region and a modulator region. The amplifier region has a constant current to keep the region near the lasing threshold. The modulator region has a small varying forward current or reverse bias voltage which controls the light output of the laser. This two section blue laser diode requires much lower power consumption than directly modulated lasers which reduces transient heating and “drooping” of the light output.

Abstract: A p-n tunnel junction between a p-type semiconductor layer and a n-type semiconductor layer provides current injection for an nitride based vertical cavity surface emitting laser or light emitting diode structure. The p-n tunnel junction reduces the number of p-type semiconductor layers in the nitride based semiconductor VCSEL or LED structure which reduces the distributed loss, reduces the threshold current densities, reduces the overall series resistance and improves the structural quality of the laser by allowing higher growth temperatures.

Abstract: A method is provided for fabricating a nitride based resonant cavity semiconductor structure with a first distributed Bragg reflector on a sapphire substrate, a second substrate bonded to the first distributed Bragg reflector, the sapphire substrate removed by laser-assisted epitaxial lift-off, and fabricating a second Bragg reflector on the semiconductor structure opposite the first distributed Bragg reflector. The nitride based resonant cavity semiconductor structure can be a VCSEL, LED or photodetector, or a combination of said devices.

Abstract: A method for placing nitride laser diode arrays on a thermally conducting substrate is described. The method uses an excimer laser to detach the nitride laser diode from the sapphire growth substrate after a thermally conducting substrate has been bonded to the side opposite the sapphire substrate.

Abstract: A structure and method for an asymmetric waveguide nitride laser diode without need of a p-type waveguide is disclosed. The need for a high aluminum tunnel barrier layer in the laser is avoided.

Abstract: An index-guided buried heterostructure AlGaInN laser diode provides improved mode stability and low threshold current when compared to conventional ridge waveguide structures. A short period superlattice is used to allow adequate cladding layer thickness for confinement without cracking. The intensity of the light lost due to leakage is reduced by about 2 orders of magnitude with an accompanying improvement in the far-field radiation pattern when compared to conventional structures.

Abstract: A structure and method for an asymmetric waveguide nitride laser diode without need of a p-type waveguide is disclosed. The need for a high aluminum tunnel barrier layer in the laser is avoided.

Abstract: A structure and method for an asymmetric waveguide nitride laser diode without need of a p-type waveguide is disclosed. The need for a high aluminum tunnel barrier layer in the laser is avoided.

Abstract: Methods for cleaving semiconductor structures formed on c-face sapphire substrates are disclosed. An exemplary method includes forming at least one III-V nitride layer on the top c-face of a c-face sapphire substrate. A line of weakness is formed on the bottom c-face of the c-face sapphire substrate in the a-plane direction of the c-face sapphire substrate. A force is applied to the bottom c-face to cleave the c-face sapphire substrate along the line of weakness in the a-plane direction, and to form a cleaved facet along an m-plane of each III-V nitride layer. The III-V nitride layers can be included in laser diodes and other light-emitting devices.

Abstract: A method for placing nitride laser diode arrays on a thermally conducting substrate is described. The method uses an excimer laser to detach the nitride laser diode from the sapphire growth substrate after an intermediate substrate has been attached to the side opposite the sapphire substrate. A thermally conducting substrate is subsequently bonded to the side where the sapphire substrate was removed.

Abstract: Group III-V nitride semiconductors are used as optoelectronic light emitters. The semiconductor alloy InGaN is used as the active region in nitride laser diodes and LEDs, as its bandgap energy can be tuned by adjusting the alloy composition, to span the entire visible spectrum. InGaN layers of high-indium content, as required for blue or green emission are difficult to grow, however, because the poor lattice mismatch between GaN and InGaN causes alloy segregation. In this situation, the inhomogeneous alloy composition results in spectrally impure emission, and diminished optical gain. To suppress segregation, the high-indium-content InGaN active region may be deposited over a thick InGaN layer, substituted for the more typical GaN. First depositing a thick InGaN layer establishes a larger lattice parameter than that of GaN. Consequently, a high indium content heterostructure active region grown over the thick InGaN layer experiences significantly less lattice mismatch compared to GaN.