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Alexandre M. Bratkovski, Mountain View US

Alexandre M. Bratkovski, Mountain View, CA US

Patent application numberDescriptionPublished
20080218740Nanowire-based photonic devices - Embodiments of the present invention are related to nanowire-based devices that can be configured and operated as modulators, chemical sensors, and light-detection devices. In one aspect, a nanowire-based device includes a reflective member, a resonant cavity surrounded by at least a portion of the reflective member, and at least one nanowire disposed within the resonant cavity. The nanowire includes at least one active segment selectively disposed along the length of the nanowire to substantially coincide with at least one antinode of light resonating within the cavity. The active segment can be configured to interact with the light resonating within the cavity.09-11-2008
20080219311Optical structures including selectively positioned color centers, photonic chips including same, and methods of fabricating optical structures - Various aspects of the present invention are directed to optical structures including selectively positioned color centers, methods of fabricating such optical structures, and photonic chips that utilize such optical structures. In one aspect of the present invention, an optical structure includes an optical medium having a number of strain-localization regions. A number of color centers are distributed within the optical medium in a generally selected pattern, with at least a portion of the strain-localization regions including one or more of the color centers. In another aspect of the present invention, a method of positioning color centers in an optical medium is disclosed. In the method, a number of strain-localization regions are generated in the optical medium. The optical medium is annealed to promote diffusion of at least a portion of the color centers to the strain-localization regions.09-11-2008
20080239462Composite material with controllable resonant cells - An apparatus for controlling propagation of incident electromagnetic radiation is described, comprising a composite material having electromagnetically reactive cells of small dimension relative to a wavelength of the incident electromagnetic radiation. At least one of a capacitive and inductive property of at least one of the electromagnetically reactive cells is temporally controllable to allow temporal control of an associated effective refractive index encountered by the incident electromagnetic radiation while propagating through the composite material.10-02-2008
20080258079Apparatuses and methods for up-converting electromagnetic radiation - Various aspects of the present invention are directed to apparatuses and methods for up-converting electromagnetic radiation. In one aspect of the present invention, a plasmonic up-converter apparatus includes an excitation source operable to emit electromagnetic radiation at an excitation frequency and at least one array of nanofeatures. The at least one array of nanofeatures is configured to produce an emission spectrum responsive to irradiation by the electromagnetic radiation. The emission spectrum has an intensity at a second harmonic frequency or a third harmonic frequency approximately equal to an intensity at a fundamental harmonic frequency, with the fundamental harmonic frequency being approximately equal to the excitation frequency. Additional aspects are directed to a display that utilizes any of the disclosed plasmonic up-converter apparatuses, a laser in which a laser medium is optically pumped using electromagnetic radiation produced by one of the disclosed plasmonic up-converter apparatuses, and methods of up-converting electromagnetic radiation.10-23-2008
20080259981Photonic device including semiconductor structure having doped region with array of subwavelength recesses - Various aspects of the present invention are directed to photonic devices, such as electro-optic modulators, passive filters, and tunable filters. In one aspect of the present invention, a photonic device includes a semiconductor structure having a p-region and an n-region. A doped region is formed on or within the semiconductor structure. The doped region includes at least one generally periodic array of recesses, with the at least one generally periodic array configured to transmit electromagnetic radiation at a selected dominant wavelength. The selected dominant wavelength is tunable by varying the refractive index of the semiconductor structure.10-23-2008
20080266556Nanowire configured to couple electromagnetic radiation to selected guided wave, devices using same, and methods of fabricating same - Various aspects of the present invention are directed to a nanowire configured to couple electromagnetic radiation to a selected guided wave and devices incorporating such nanowires. In one aspect of the present invention, a nanowire structure includes a substrate and at least one nanowire attached to the substrate. A diameter, composition, or both may vary generally periodically along a length of the at least one nanowire. A coating may cover at least part of a circumferential surface of the at least one nanowire. The nanowire structure may be incorporated in a device including at least one optical-to-electrical converter operable to convert a guided wave propagating along the length of the at least one nanowire, at least in part responsive to irradiation, to an electrical signal. Other aspects of the present invention are directed to methods of fabricating nanowires structured to support guided waves.10-30-2008
20080266640Structure and method for modulating light - A structure includes a film having a plurality of nanoapertures and a semiconductor layer in connection with the film. The nanoapertures are configured to allow the transmission of a predetermined subwavelength of light through the film via the plurality of nanoapertures. The semiconductor layer facilitates the modulation of the predetermined subwavelength of light transmitted through the film. The structure also includes a carrier generator for modulating the predetermined subwavelength of light by generating charge carriers10-30-2008
20080285917Method and apparatus for controlling light flux with sub-micron plasmon waveguides - Apparatuses and methods for modulating electromagnetic radiation are disclosed. A plasmon waveguide including an array of metallic nanoparticles disposed on a dielectric substrate is provided. The plasmon waveguide is disposed on a MEMS structure. An electromagnetic radiation signal is applied to a tapered fiber disposed proximate the MEMS structure. The intensity of the electromagnetic radiation signal passing through the tapered fiber is modified by displacing a deformable member of the MEMS structure to modify a distance between the plasmon waveguide and the tapered fiber such that an evanescent field of the tapered fiber causes a plasmon resonance in the plasmon waveguide.11-20-2008
20080310790Nanowire-based photodetectors - Various embodiments of the present invention are directed to nanowire-based photodetectors that can be used to convert information encoded in a channel of electromagnetic radiation into a photocurrent encoding the same information. In one embodiment of the present invention, a photodetector comprises a waveguide configured to transmit one or more channels of electromagnetic radiation. The photodetector includes a first terminal and a second terminal. The first terminal and the second terminal are positioned on opposite sides of the waveguide. The photodetector also includes a number of nanowires. Each nanowire interconnects the first terminal to the second terminal and a portion of each nanowire is embedded in the waveguide.12-18-2008
20090001498Nanowire photodiodes and methods of making nanowire photodiodes - Nanowire-based photodiodes are disclosed. The photodiodes include a first optical waveguide having a tapered first end, a second optical waveguide having a tapered second end, and at least one nanowire comprising at least one semiconductor material connecting the first and second ends in a bridging configuration. Methods of making the photodiodes are also disclosed.01-01-2009
20090015838Structure having nanoapertures - A structure includes a film having a plurality of nanoapertures. The nanoapertures are configured to allow the transmission of a predetermined subwavelength of light through the film via the plurality of nanoapertures. The structure also includes a semiconductor layer in connection with the film to facilitate the detection of the predetermined subwavelength of light transmitted through the film.01-15-2009
20090027778Deformable optical element, methods of making and uses thereof - A deformable optical element includes an elastically deformable lens. Electrical contacts are directly attached to the elastically deformable lens and configured to receive an applied voltage. The electrical contacts have opposing surfaces configured to develop electrostatic forces in response to the applied voltage. The electrostatic forces deform the elastically deformable lens to create a predetermined optical effect.01-29-2009
20090032798LIGHT EMITTING DIODE (LED) - A light-emitting diode (LED) includes a p-type layer, an n-type layer, and an active layer arranged between the p-type layer and the n-type layer. The active layer includes at least one quantum well adjacent to at least one modulation-doped layer. Alternatively, or in addition thereto, at least one surface of the n-type layer or the p-type layer is texturized to form a textured surface facing the active layer.02-05-2009
20090034050FRESNEL ANTENNA - A Fresnel antenna includes a plurality of Fresnel elements spaced to selectively attenuate electromagnetic waves having a predetermined wavelength, selected wavelengths, or range of wavelengths, and to concentrate electromagnetic waves having a predetermined wavelength, selected wavelengths, or range of wavelengths other than the attenuated wavelengths.02-05-2009
20090034908PHOTONIC GUIDING DEVICE - A photonic guiding device and methods of making and using are disclosed. The photonic guiding device comprises a large core hollow waveguide configured to interconnect electronic circuitry on a circuit board. A reflective coating covers an interior of the hollow waveguide to provide a high reflectivity to enable light to be reflected from a surface of the reflective coating. A collimator is configured to collimate multi-mode coherent light directed into the hollow waveguide.02-05-2009
20090034977MULTIPLEXING HIGH SPEED LIGHT EMITTING DIODES (LEDs) - A system for multiplexing a plurality of high speed light emitting diodes (HSLEDs) includes a plurality of HSLEDs. Each of the plurality of HSLEDs emits a wavelength of light at a speed greater than or equal to about 1 Gigabyte per second. A multiplexer receives the wavelengths of light from the plurality of HSLEDs and combines the wavelengths of light for transmission over a channel. A method of multiplexing the plurality of HSLEDs is also disclosed.02-05-2009
20090087139Photonic guiding device - A photonic guiding device and methods of making and using are disclosed. The photonic guiding device comprises a large core hollow waveguide configured to interconnect electronic circuitry on a circuit board. A reflective coating covers an interior of the hollow waveguide to provide a high reflectivity to enable light to be reflected from a surface of the reflective coating. A collimator is configured to collimate multi-mode coherent light directed into the hollow waveguide.04-02-2009
20090103862WAVEGUIDE SYSTEM WITH DIFFRACTING STRUCTURE - An optical waveguide system includes an optical element, a three-dimensional diffracting structure positioned around the optical element, and a waveguide. The optical element and the diffracting structure are at least partially enclosed by the waveguide.04-23-2009
20090103930Method and system of tracking optical beam shift - An optical interconnect includes an optical transmitter having a plurality of optical sources; a light sensing array configured to receive optical beams emitted from the optical sources; and a beam tracking module in communication with the light sensing array. The beam tracking module is configured to calculate a displacement of at least one of the optical beams by extrapolating an extremum from cross-correlation data obtained between at least a portion of a sample reading from the light sensing array and at least a portion of a plurality of shifted versions of a reference reading from the light sensing array. A related method includes calculating a displacement of an optical beam by extrapolating an extremum from cross-correlation data obtained between a sample reading of the optical beam and at least a portion of a plurality of shifted versions of a reference reading from the light sensing array.04-23-2009
20100079754SYSTEMS FOR PERFORMING RAMAN SPECTROSCOPY - Various embodiments of the present invention relate generally to systems for performing Raman spectroscopy. In one embodiment, a system for performing Raman spectroscopy comprises an analyte holder having a surface configured to retain an analyte and a light concentrator configured to receive an incident beam of light, split the incident beam into one or more beams, and direct the one or more beams to substantially intersect at the surface. The system may also include a collector configured to focus each of the one or more beams onto the surface, collect the Raman scattered light emitted from the analyte, and direct the Raman scattered light away from the surface.04-01-2010
20100091274Plasmonic electric-field concentrator arrays and systems for performing raman spectroscopy - Various embodiments of the present invention relate to plasmonic electric-field concentrators and to systems incorporating the plasmonic electric-field concentrators to perform Raman spectroscopy. In one aspect, a plasmonic electric-field concentrator comprises two or more large features, and a relatively small feature similar in shape to large features positioned adjacent to the two or more large features. The features are arranged so that when light of an appropriate wavelength is incident on the features, surface plasmon polaritons form on the outer surfaces of the features. The surface plasmon polaritons have associated electric fields extending perpendicular to the surfaces of the features. The electric fields are concentrated in the space between features forming an electric field hot spot that enhances Raman scattered light emitted from an analyte proximate to or absorbed on the features.04-15-2010
20100155686MEMRISTIVE DEVICE - A memristive device includes a first electrode, a second electrode, and an active region disposed between the first and second electrodes. At least one of the first and second electrodes is a metal oxide electrode.06-24-2010
20100265552Dynamically reconfigurable negative index material crossbars with gain - Various embodiments of the present invention are directed to negative index material crossbars that can be electronically controlled and dynamically reconfigured to exhibit a variety of electromagnetic properties. In one aspect, a negative index material crossbar comprises a first layer of non-crossing nanowires, and a second layer of approximately parallel nanowires that overlay the nanowires in the first layer. Resonant elements at nanowire intersections, and a gain material incorporated in the crossbar such that transmitted electromagnetic radiation with wavelengths in a wavelength band of interest is enhanced when the crossbar is flood pumped with pump electromagnetic radiation.10-21-2010
20100275686INERTIAL SENSING SYSTEM WITH A CURVED BASE AND A DIAMAGNETIC MASS - An inertial sensing system includes a diamagnetic mass, a plurality of permanent magnets positioned to form a curved base, wherein the plurality of permanent magnets are configured to provide an inhomogeneous magnetic field upon which the diamagnetic mass becomes levitated above the plurality of permanent magnets within the curved base and wherein the curved base also provides a confinement potential to substantially prevent the diamagnetic mass from exiting an interior of the curved base, and a tracking apparatus for monitoring at least one of a position and an orientation of the diamagnetic mass with respect to the curved structure.11-04-2010
20100277789Negative index material-based modulators and methods for fabricating the same - Various embodiments of the present invention are directed to external, electronically controllable, negative index material-based modulators. In one aspect, an external modulator comprises a negative index material in electronic communication with an electronic signal source. The negative index material receives an electronic signal encoding data from the electronic signal source and an unmodulated carrier wave from an electromagnetic radiation source. Magnitude variations in the electronic signal produce corresponding effective refractive index changes in the negative index material encoding the data in the amplitude and/or phase of the carrier wave to produce an electromagnetic signal.11-04-2010
20100277791Scrambling and descrambling systems for secure communication - Various embodiments of the present invention are directed to scrambling-descrambling systems for encrypting and decrypting electromagnetic signals transmitted in optical and wireless networks. In one aspect, a system (11-04-2010
20100278474DEVICE WITH TUNABLE PLASMON RESONANCE - A device includes a resonator capable of supporting a plasmon mode, a gain structure arranged to couple energy into the resonator, and a memristive layer arranged to provide an interaction with the plasmon mode. An electric signal applied to the memristive layer can change the interaction and change a resonant frequency of the plasmon mode.11-04-2010
20100278479MEMRISTIVE ARRAY WITH WAVEGUIDE - A device includes one or more waveguides and a memristive array adjacent to the waveguide(s). The memristive array is programmable to form a pattern that diffracts light and couples diffracted light into or out of the waveguide(s).11-04-2010
20100321684SIGNAL-AMPLIFICATION DEVICE FOR SURFACE ENHANCED RAMAN SPECTROSCOPY - A signal-amplification device for surface enhanced Raman spectroscopy (SERS). The signal-amplification device includes a non-SERS-active (NSA) substrate, a plurality of multi-tiered non-SERS-active nanowire (MNSANW) structures and a plurality of metallic SERS-active nanoparticles. In addition, a MNSANW structure of the plurality of MNSANW structures includes a main arm of a plurality of main arms and a plurality of arms of at least secondary order. The plurality of main arms is disposed on the NSA substrate; and, a secondary arm of the plurality of arms is disposed on the main arm. Moreover, a metallic SERS-active nanoparticle of the plurality of metallic SERS-active nanoparticles is disposed on a surface of the MNSANW structure.12-23-2010
20110014457Graphene Layer With An Engineered Stress Supported On A Substrate - A structure comprising a layer of graphene supported on a substrate wherein the substrate is pre-selected to have a coefficient of thermal expansion that is either matched within about 10% of that of graphene or mis-matched, thereby inducing controlled stress in the graphene layer to control electrical and/or mechanical properties of devices fabricated in the graphene layer.01-20-2011
20110017977MEMRISTORS WITH INSULATION ELEMENTS AND METHODS FOR FABRICATING THE SAME - Embodiments of the present invention are directed to nanoscale memristor devices that provide nonvolatile memristive switching. In one embodiment, a memristor device comprises an active region disposed between a first electrode and a second electrode. The device includes a first insulation element disposed between the first electrode and an outer portion of a first surface of the active region. The first insulation element is configured with one or more opening through which the first electrode makes physical contact with the active region. The device also includes a second insulation element disposed between the second electrode and an outer portion of a second surface of the active region. The second insulation element is configured with one or more opening through which the second electrode makes physical contact with the second surface.01-27-2011
20110024710MEMRISTOR WITH A NON-PLANAR SUBSTRATE - A memristor includes a substrate having a plurality of protrusions, wherein each of the plurality of protrusions extends in a first direction, a first electrode provided over at least one of the plurality of protrusions, wherein the first electrode conforms to the shape of the at least one protrusion such that the first electrode has a crest, a switching material positioned upon the first electrode; and a second electrode positioned upon the switching material such that a portion of the second electrode is substantially in line with the crest of the first electrode along the first direction, wherein an active region in the switching material is operable to be formed between the crest of the first electrode and the portion of the second electrode that is substantially in line with the crest of the first electrode.02-03-2011
20110024716MEMRISTOR HAVING A NANOSTRUCTURE IN THE SWITCHING MATERIAL - A memristor includes a first electrode having a first surface, at least one electrically conductive nanostructure provided on the first surface, in which the at least one electrically conductive nanostructure is relatively smaller than a width of the first electrode, a switching material positioned upon said first surface, in which the switching material covers the at least one electrically conductive nanostructure, and a second electrode positioned upon the switching material substantially in line with the at least one electrically conductive nanostructure, in which an active region in the switching material is formed substantially between the at least one electrically conductive nanostructure and the first electrode.02-03-2011
20110075967Cylindrical Resonators For Optical Signal Routing - A system for routing optical signals includes a waveguide array and a cylindrical resonator lying across the waveguide array, the cylindrical resonator having independently controllable tangential interfaces with each of the waveguides within the waveguide array. A method of selectively routing an optical signal between waveguides includes selecting a optical signal to route; determining the desired path the optical signal; tuning a first controllable interface between a cylindrical resonator and a source waveguide to extract the optical signal from the source waveguide; and tuning a second independently controllable interface between the cylindrical resonator and a destination waveguide to deposit the optical signal into the destination waveguide.03-31-2011
20110081109NANOPARTICLE ARRAY PHOTONIC WAVEGUIDE - A nanoparticle array photonic waveguide, a photonic transmission system and a method of photonic transmission compensate for optical loss in an optical signal through stimulated emission using an optical gain material in a core of composite nanoparticles. The nanoparticle array photonic waveguide includes a plurality of the composite nanoparticles arranged adjacent to one another in a row. A composite nanoparticle of the plurality includes a shell and a core. The shell includes a negative dielectric constant material that is capable of supporting an optical signal on a surface of the shell. The core is adjacent to a side of the shell opposite to the shell surface. The core includes an optical gain material (OGM) that is capable of providing optical gain to the optical signal through stimulated emission within the OGM.04-07-2011
20110096218NANOWIRE PHOTODIODES - A photodiode includes a first electrode, a second electrode, and a nanowire comprising a semiconductor core and a semiconductor shell. The nanowire has a first end and a second end, the first end being in electrical contact with the first electrode and the second end being in contact with the second electrode.04-28-2011
20110141541ACTIVE CHIRAL PHOTONIC METAMATERIAL - An active chiral photonic metamaterial having a dynamically controllable photonic material parameter is employed in a system and a method of polarization rotation. The active chiral photonic metamaterial includes a first chiral photonic element formed in a first metal layer, a second chiral photonic element formed in a second metal layer, and an active material layer disposed between the first and second metal layers. The active material layer includes the photonic material parameter that is dynamically controllable. A coupling between the first chiral photonic element and the second chiral photonic element is a function of the photonic material parameter of the active material layer. The system further includes a means for controlling the dynamically controllable photonic material parameter. The method includes illuminating the active chiral photonic metamaterial with an optical signal and applying a control signal to vary the dynamically controllable photonic material parameter.06-16-2011
20110141546TUNABLE NANOWIRE RESONANT CAVITY FOR OPTICAL MODULATION - A resonant cavity with tunable nanowire. The resonant cavity includes a substrate. The substrate is coupleable to an optical resonator structure. The resonant cavity also includes a plurality of nanowires formed on the substrate. The plurality of nanowires is actuated in response to an application of energy.06-16-2011

Patent applications by Alexandre M. Bratkovski, Mountain View, CA US