Abstract: The electroabsorption modulator comprises a p-i-n junction structure that includes an active layer, a p-type cladding layer and an n-type cladding layer with the active layer sandwiched between the cladding layers. The electroabsorption modulator additionally comprises a quantum well structure located within the active layer. The p-type cladding layer comprises a layer of heavily-doped low-diffusivity p-type semiconductor material located adjacent the active layer that reduces the extension of the depletion region into the p-type cladding layer when a reverse bias is applied to the electroabsorption modulator. The reduced extension increases the strength of the electric field applied to the quantum well structure by a given reverse bias voltage. The increased field strength increases the extinction ratio of the electroabsorption modulator.

Abstract: A distributed Bragg reflector and a method of fabricating the same incorporates a support for supporting the gaps against collapse. The method includes forming a plurality of alternating structure and sacrificial layers on a substrate. The structure and sacrificial layers are etched into at least one mesa protruding from the substrate. A support layer is formed on the at least one mesa leaving a portion of the structure and sacrificial layers exposed. At least a portion of at least one of the exposed sacrificial layers are etched from between the structure layers to form gaps between the structure layers.

Abstract: A light modulator having a waveguide and a resonator is disclosed. The waveguide routes light of wavelength ? past the resonator. The resonator is coupled to the waveguide such that a portion of the light is input to the resonator, the resonator having a resonance at ?. The resonator includes a gain region in which light of wavelength ? is amplified and an absorption region in which light of wavelength ? is absorbed, the absorption region having first and second states, the first state absorbing less light of wavelength ? than the second state, the state of the absorption region is determined by an electrical signal coupled to the absorption region. The gain region provides a gain that compensates for the light absorption in the first state. In one embodiment, the waveguide and resonator are critically coupled when the absorption region is in the second state.

Abstract: The active region of a long-wavelength light emitting device is made by providing an organometallic vapor phase epitaxy (OMVPE) reactor, placing a substrate wafer capable of supporting growth of indium gallium arsenide nitride in the reactor, supplying a Group III–V precursor mixture comprising an arsenic precursor, a nitrogen precursor, a gallium precursor, an indium precursor and a carrier gas to the reactor and pressurizing the reactor to a sub-atmospheric elevated growth pressure no higher than that at which a layer of indium gallium arsenide layer having a nitrogen fraction commensurate with light emission at a wavelength longer than 1.2 ?m is deposited over the substrate wafer.

Abstract: A distributed Bragg reflector and a method of fabricating the same incorporates a support for supporting the gaps against collapse. The method includes forming a plurality of alternating structure and sacrificial layers on a substrate. The structure and sacrificial layers are etched into at least one mesa protruding from the substrate. A support layer is formed on the at least one mesa leaving a portion of the structure and sacrificial layers exposed. At least a portion of at least one of the exposed sacrificial layers are etched from between the structure layers to form gaps between the structure layers.

Abstract: A modulator having a waveguide and a microdisk resonator is disclosed. The waveguide has an input port for receiving a light signal of wavelength ? and an output port for transmitting modulated light. The microdisk resonator has a resonance at ? and is coupled to the waveguide between the input and output ports such that at least 10 percent of the light traveling in the waveguide is coupled to the microdisk resonator. The microdisk resonator further includes a material having a first state and a second state, the material absorbing more of the light in the first state than in the second state. The first and second states are selectable by a signal that is applied to the microdisk resonator. In one embodiment, the waveguide and the microdisk resonator occupy different portions of a sheet of material having the various layers used to construct the resonator.

Abstract: An optical semiconductor device having an active layer for generating light via the recombination of holes and electrons therein. The active layer is part of a plurality of semiconductor layers including an n-p junction between an n-type layer and a p-type layer. The active layer has a polarization field therein having a field direction that depends on the orientation of the active layer when the active layer is grown. In the present invention, the polarization field in the active layer has an orientation such that the polarization field is directed from the n-layer to the p-layer.

Abstract: The electroabsorption modulator comprises a p-i-n junction structure that includes an active layer, a p-type cladding layer and an n-type cladding layer with the active layer sandwiched between the cladding layers. The electroabsorption modulator additionally comprises a quantum well structure located within the active layer. The p-type cladding layer comprises a layer of heavily-doped low-diffusivity p-type semiconductor material located adjacent the active layer that reduces the extension of the depletion region into the p-type cladding layer when a reverse bias is applied to the electroabsorption modulator. The reduced extension increases the strength of the electric field applied to the quantum well structure by a given reverse bias voltage. The increased field strength increases the extinction ratio of the electroabsorption modulator.

Abstract: The active region of a long-wavelength light emitting device is made by providing an organometallic vapor phase epitaxy (OMVPE) reactor, placing a substrate wafer capable of supporting growth of indium gallium arsenide nitride in the reactor, supplying a Group III-V precursor mixture comprising an arsenic precursor, a nitrogen precursor, a gallium precursor, an indium precursor and a carrier gas to the reactor and pressurizing the reactor to a sub-atmospheric elevated growth pressure no higher than that at which a layer of indium gallium arsenide layer having a nitrogen fraction commensurate with light emission at a wavelength longer than 1.2 &mgr;m is deposited over the substrate wafer.

Abstract: A modulated light emitter having a laser and modulator constructed on a common substrate. The light emitter includes an active layer having a quantum well (QW) layer sandwiched between first and second barrier layers. The active layer includes a laser region and a modulator region connected by a waveguide. The laser region emits light when a potential is applied across the active layer in the laser region. The modulator region has a first state in which the modulator region absorbs the generated light and a second state in which the modulator region transmits the generated light. The modulator region assumes either the first or second state depending on the potential across the modulator region. The QW layer in the modulator region is under a tensile strain, which provides improved light absorption in the first state.

Abstract: An optical signal emitter for a multi-channel, wavelength division multiplexed (WDM) optical communication system is disclosed. This optical signal emitter does not require an optical multiplexer, or other device, to combine components of an optical signal. Semiconductor die attached to a substrate emit independent components of a multi-channel optical signal from emission apertures that are positioned offset from the center of the die toward an aperture corner of the die. This aperture corner may be shaped so that the apertures can be located closer to each other. The shaping of the die may include a photolithographic process, an etching process, a reactive ion etching process, or a combination thereof.

Abstract: The invention provides a laser structure that operates at a wavelength of 1.3 &mgr;m and at elevated temperatures and a method of making same. The laser structure includes a quantum well layer of InAsP. The quantum well layer is sandwiched between a first barrier layer and a second barrier layer. Each barrier layer exhibits a higher bandgap energy than the quantum well layer. Also, each barrier layer comprises Gax(AlIn)1−xP in which x 0. This material has a higher bandgap energy than conventional barrier layer materials, such as InGaP. The resulting larger conduction band discontinuity leads to improved high temperature performance without increasing the threshold current of the laser structure.

Abstract: The long-wavelength photonic device comprises an active region that includes at least one quantum-well layer of a quantum-well layer material that comprises InyGa1-yAsSb in which y≧0, and that additionally includes a corresponding number of barrier layers each of a barrier layer material that includes gallium and phosphorus. The barrier layer material has a conduction-band energy level greater than the conduction-band energy level of the quantum-well layer material and has a valence-band energy level less than the valence-band energy level of the quantum-well layer material.

Abstract: A modulated light emitter having a laser and modulator constructed on a common substrate. The light emitter includes an active layer having a quantum well (QW) layer sandwiched between first and second barrier layers. The active layer includes a laser region and a modulator region connected by a waveguide. The laser region emits light when a potential is applied across the active layer in the laser region. The modulator region has a first state in which the modulator region absorbs the generated light and a second state in which the modulator region transmits the generated light. The modulator region assumes either the first or second state depending on the potential across the modulator region. The QW layer in the modulator region is under a tensile strain, which provides improved light absorption in the first state.

Abstract: Mass spectometer system and method of use are disclosed. Briefly described, one embodiment of the mass spectrometry system, among others, includes a radio frequency multipole assembly, an inner structure, and a laser diode array system. The inner structure has an outside, an inside, and an opening. The inner structure substantially surrounds the radio frequency multipole assembly. The laser diode array system is disposed on the outside of the inner structure adjacent the side opening such that laser radiation emitted from the laser diode array system travels through the side opening.

Abstract: The long-wavelength photonic device comprises an active region that includes at least one quantum-well layer of a quantum-well layer material that comprises InyGa1-yAsSb in which y≧0, and that additionally includes a corresponding number of barrier layers each of a barrier layer material that includes gallium and phosphorus. The barrier layer material has a conduction-band energy level greater than the conduction-band energy level of the quantum-well layer material and has a valence-band energy level less than the valence-band energy level of the quantum-well layer material.

Abstract: A vertical-cavity surface-emitting laser incorporating a supported air gap distributed Bragg reflector is disclosed. The supported air gap DBR includes a regrowth layer of material that provides mechanical support for the original material layers. The supported air gap DBR is fabricated by first growing alternating pairs of a first material and a sacrificial material over a suitable substrate. The layer pairs of the first material and sacrificial material are covered by a suitable dielectric material. The dielectric material is then selectively removed exposing regions of the first material and sacrificial material where selective regrowth of additional material is desired. The selective regrowth of the additional material provides mechanical support for the semiconductor material that remains after a selective etch removal of the sacrificial material.

Abstract: A distributed Bragg reflector and a method of fabricating the same incorporates a support for supporting the gaps against collapse. The method includes forming a plurality of alternating structure and sacrificial layers on a substrate. The structure and sacrificial layers are etched into at least one mesa protruding from the substrate. A support layer is formed on the at least one mesa leaving a portion of the structure and sacrificial layers exposed. At least a portion of at least one of the exposed sacrificial layers are etched from between the structure layers to form gaps between the structure layers.

Abstract: An optical assembly includes an optical subassembly containing a prefabricated long wavelength laser optically coupled to a prefabricated short wavelength laser located in a housing. The optical subassembly may be removably installed in the housing in which the short wavelength laser is contained. The short wavelength laser optically pumps the long wavelength laser resulting in a long wavelength laser output. The optical subassembly allows the independent fabrication, optimization and testing of the short wavelength laser and the long wavelength laser.

Abstract: A light-generating device such as a laser or LED. A light-generating device according to the present invention includes a first n-electrode layer in contact with a first n-contact layer, the first n-contact layer including an n-doped semiconductor. Light is generated by the recombination of holes and electrons in an n-p active layer. The n-p active layer includes a first p-doped layer in contact with a first n-doped layer, the first n-doped layer being connected electrically with the first n-contact layer. A p-n reverse-biased tunnel diode constructed from a second p-doped layer in contact with a second n-doped layer is connected electrically such that the second p-doped layer is connected electrically with the first p-layer. A second n-contact layer constructed from an n-doped semiconductor material is connected electrically to the second n-doped layer. A second n-electrode layer is placed in contact with the second n-contact layer.