Patents by Inventor Alexandre Bratkovski

Alexandre Bratkovski has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20090190875
    Abstract: An optical modulator and related methods are described. In accordance with one embodiment, the optical modulator comprises a waveguide for guiding an optical signal, and further comprises a ring resonator disposed in evanescent communication with the waveguide for at least one predetermined wavelength of the optical signal. The optical modulator further comprises a semiconductor pnpn junction structure that is at least partially coextensive with at least a portion of a resonant light path of the ring resonator. The optical modulator is configured such that the semiconductor pnpn junction structure receives an electrical control signal thereacross. The electrical control signal controls a free carrier population in the resonant light path where coextensive with the pnpn junction structure. A resonance condition of the ring resonator at the predetermined wavelength is thereby controlled by the electrical control signal, and the optical signal is thereby modulated according to the electrical control signal.
    Type: Application
    Filed: October 1, 2008
    Publication date: July 30, 2009
    Inventors: Alexandre Bratkovski, Theodore I. Kamins
  • Patent number: 7561320
    Abstract: An apparatus and related methods for modulating an electromagnetic radiation beam are described. A composite material is positioned in the path of the radiation beam, the composite material comprising a plurality of commonly oriented metallic first lines spaced apart by less than a wavelength of the radiation beam and a plurality of commonly oriented metallic second lines also spaced apart by less than that wavelength. The second lines are positioned in a crossing arrangement with the first lines, a crosspoint location being defined where each first line crosses each second line. An electrically programmable impedance memory element is positioned at each crosspoint location and is electrically coupled between the first and second lines corresponding to that crosspoint location, each impedance memory element having an electrically programmed state. The composite material modulates the radiation beam according to the electrically programmed states of the impedance memory elements.
    Type: Grant
    Filed: October 26, 2007
    Date of Patent: July 14, 2009
    Assignee: Hewlett-Packard Development Company, L.P.
    Inventors: Shih-Yuan Wang, Alexandre Bratkovski, R. Stanley Williams
  • Patent number: 7545014
    Abstract: A composite material for providing at least one of a negative effective permeability and a negative effective permittivity for incident radiation of at least one wavelength is described. The composite material comprises a plurality of three-dimensional resonant cells disposed across a first substrate. Each three-dimensional resonant cell comprises a base substantially parallel to the substrate and at least three sidewalls upwardly extending therefrom. Each upwardly extending sidewall comprises a sidewall substrate having at least one conductor patterned thereon. Each upwardly extending sidewall is fabricated by forming the sidewall substrate as a substantially horizontal layer above the first substrate, lithographically patterning the sidewall substrate with the at least one conductor while horizontally disposed above the first substrate, and tilting up the sidewall substrate to the upwardly extending position.
    Type: Grant
    Filed: October 12, 2006
    Date of Patent: June 9, 2009
    Assignee: Hewlett-Packard Development Company, L.P.
    Inventors: Shih-Yuan Wang, Alexandre Bratkovski, Wei Wu
  • Patent number: 7545841
    Abstract: An apparatus and related methods are described, the apparatus comprising a composite material layer configured to exhibit at least one of a negative effective permittivity and a negative effective permeability for radiation of at least one wavelength propagating therethrough. The apparatus further comprises a layer of gain material proximal to the composite material layer, the layer of gain material providing amplification for the propagating radiation. The layer of gain material is disposed within a laser cavity and pumped to a lasing condition for the laser cavity, the layer of gain material thereby providing gain-clamped amplification for the propagating radiation.
    Type: Grant
    Filed: April 24, 2007
    Date of Patent: June 9, 2009
    Assignee: Hewlett-Packard Development Company, L.P.
    Inventors: Shih-Yuan Wang, Alexandre Bratkovski
  • Patent number: 7528948
    Abstract: An apparatus and related methods for facilitating surface-enhanced Raman spectroscopy (SERS) is described. The apparatus comprises a SERS-active structure near which a plurality of analyte molecules are disposed and an actuation device in actuable communication with the SERS-active structure to deform the SERS-active structure while the analyte molecules are disposed therenear. The deformation of the SERS-active structure varies an intensity of radiation Raman-scattered from the analyte molecules.
    Type: Grant
    Filed: July 25, 2006
    Date of Patent: May 5, 2009
    Assignee: Hewlett-Packard Development Company, L.P.
    Inventors: Alexandre Bratkovski, Duncan R. Stewart
  • Publication number: 20090109516
    Abstract: An apparatus and related methods for modulating an electromagnetic radiation beam are described. A composite material is positioned in the path of the radiation beam, the composite material comprising a plurality of commonly oriented metallic first lines spaced apart by less than a wavelength of the radiation beam and a plurality of commonly oriented metallic second lines also spaced apart by less than that wavelength. The second lines are positioned in a crossing arrangement with the first lines, a crosspoint location being defined where each first line crosses each second line. An electrically programmable impedance memory element is positioned at each crosspoint location and is electrically coupled between the first and second lines corresponding to that crosspoint location, each impedance memory element having an electrically programmed state. The composite material modulates the radiation beam according to the electrically programmed states of the impedance memory elements.
    Type: Application
    Filed: October 26, 2007
    Publication date: April 30, 2009
    Inventors: Shih-Yuan Wang, Alexandre Bratkovski, R. Stanley Williams
  • Publication number: 20090110348
    Abstract: Various embodiments of the present invention are directed to photonic switches and switch fabrics employing the photonic switches. In one embodiment of the present invention, a photonic switch comprises a first waveguide disposed on a surface of a substrate in proximity to an opening in the substrate, and a second waveguide crossing the first waveguide and positioned in proximity to the opening in the substrate. The photonic switch includes a tunable microring resonator disposed on the surface of the substrate adjacent to the first waveguide and the second waveguide and configured with an opening aligned with the opening in the substrate. The photonic switch also includes a wire having a first end and a second end and configured to pass through the opening in the microring and the opening in the substrate.
    Type: Application
    Filed: October 20, 2008
    Publication date: April 30, 2009
    Inventors: Alexandre Bratkovski, Michael Tan, Raymond Beausoleil
  • Patent number: 7492329
    Abstract: A composite material comprising a dielectric material and a plurality of non-overlapping local resonant cell groups disposed across the dielectric material is described. Each local resonant cell group comprises a plurality of resonant cells that are small relative to a first wavelength of electromagnetic radiation that is incident upon the composite material. Each local resonant cell group has a spatial extent that is not larger than an order of the first wavelength. For each of the local resonant cell groups, the resonant cells therein are chirped with respect to at least one geometric feature thereof such that a plurality of different subsets of the resonant cells resonate for a respective plurality of wavelengths in a spectral neighborhood of the first wavelength. The composite material exhibits at least one of a negative effective permeability and a negative effective permittivity for each of the plurality of wavelengths in that spectral neighborhood.
    Type: Grant
    Filed: October 12, 2006
    Date of Patent: February 17, 2009
    Assignee: Hewlett-Packard Development Company, L.P.
    Inventors: Shih-Yuan Wang, Alexandre Bratkovski
  • Patent number: 7482727
    Abstract: A composite material exhibiting at least one of a negative effective permittivity and a negative effective permeability for incident radiation at an operating wavelength is described. The composite material comprises a dielectric layer generally parallel to a dielectric layer plane, and further comprises a first plurality of nanowire pairs disposed in the dielectric layer. Each of the first plurality of nanowire pairs comprises substantially parallel conductive nanowires of short length and separation relative to the operating wavelength. Each of the first plurality of nanowire pairs is substantially coplanar with a first plane substantially parallel to the dielectric layer plane.
    Type: Grant
    Filed: October 13, 2006
    Date of Patent: January 27, 2009
    Assignee: Hewlett-Packard Development Company, L.P.
    Inventors: Alexandre Bratkovski, Shih-Yuan Wang, Ekaterina V. Ponizovskaya
  • Patent number: 7474456
    Abstract: An apparatus and related methods for controlling propagation of incident radiation are described. In one embodiment, the apparatus comprises a composite material operable to exhibit at least one of a negative effective permittivity and a negative effective permeability for incident radiation at an operating frequency. The composite material comprises electromagnetically reactive cells of small dimension relative to a wavelength of the incident radiation. Each of the electromagnetically reactive cells comprises first and second electromagnetically reactive segments microelectromechanically movable relative to each other according to an applied control signal such that at least one of a capacitive and inductive property of the electromagnetically reactive cells is temporally controllable according to the applied control signal.
    Type: Grant
    Filed: January 30, 2007
    Date of Patent: January 6, 2009
    Assignee: Hewlett-Packard Development Company, L.P.
    Inventors: Shih-Yuan Wang, Alexandre Bratkovski
  • Patent number: 7474823
    Abstract: Dispersion compensation for an optical signal having a first frequency range is described. The optical signal is applied to a dispersion compensating material having a negatively refracting behavior within the first frequency range. The dispersion compensating material is tuned by application of a control signal that varies at least one characteristic of the dispersion compensating material associated with the negatively refracting behavior.
    Type: Grant
    Filed: October 12, 2006
    Date of Patent: January 6, 2009
    Assignee: Hewlett-Packard Development Company, L.P.
    Inventors: Shih-Yuan Wang, Alexandre Bratkovski
  • Publication number: 20080267243
    Abstract: An apparatus and related methods are described, the apparatus comprising a composite material layer configured to exhibit at least one of a negative effective permittivity and a negative effective permeability for radiation of at least one wavelength propagating therethrough. The apparatus further comprises a layer of gain material proximal to the composite material layer, the layer of gain material providing amplification for the propagating radiation. The layer of gain material is disposed within a laser cavity and pumped to a lasing condition for the laser cavity, the layer of gain material thereby providing gain-clamped amplification for the propagating radiation.
    Type: Application
    Filed: April 24, 2007
    Publication date: October 30, 2008
    Inventors: Shih-Yuan Wang, Alexandre Bratkovski
  • Publication number: 20080192331
    Abstract: An apparatus and related methods for controlling propagation of incident radiation are described. In one embodiment, the apparatus comprises a composite material operable to exhibit at least one of a negative effective permittivity and a negative effective permeability for incident radiation at an operating frequency. The composite material comprises electromagnetically reactive cells of small dimension relative to a wavelength of the incident radiation. Each of the electromagnetically reactive cells comprises first and second electromagnetically reactive segments microelectromechanically movable relative to each other according to an applied control signal such that at least one of a capacitive and inductive property of the electromagnetically reactive cells is temporally controllable according to the applied control signal.
    Type: Application
    Filed: January 30, 2007
    Publication date: August 14, 2008
    Inventors: Shih-Yuan Wang, Alexandre Bratkovski
  • Publication number: 20080174774
    Abstract: An apparatus and related methods for spectroscopic analysis of analyte molecules is described. The analyte molecules are disposed near a metallic film that is positioned between a first medium on a first side and a second medium on a second side, the second medium being of higher refractive index than the first medium. A radiation source provides excitation radiation that propagates through the second medium toward the metallic film. The second medium and the metallic film are positioned in evanescent communication with respect to the excitation radiation, and the metallic film comprises lithographically patterned features designed to intensify surface plasmon resonance along the metallic film to promote the emission of Raman radiation from the analyte molecules. A radiation detector detects the Raman radiation emitted from the analyte molecules.
    Type: Application
    Filed: January 23, 2007
    Publication date: July 24, 2008
    Inventor: Alexandre Bratkovski
  • Patent number: 7397559
    Abstract: An apparatus and related methods for spectroscopic analysis of analyte molecules is described. The analyte molecules are disposed near a metallic film that is positioned between a first medium on a first side and a second medium on a second side, the second medium being of higher refractive index than the first medium. A radiation source provides excitation radiation that propagates through the second medium toward the metallic film. The second medium and the metallic film are positioned in evanescent communication with respect to the excitation radiation, and the metallic film comprises lithographically patterned features designed to intensify surface plasmon resonance along the metallic film to promote the emission of Raman radiation from the analyte molecules. A radiation detector detects the Raman radiation emitted from the analyte molecules.
    Type: Grant
    Filed: January 23, 2007
    Date of Patent: July 8, 2008
    Assignee: Hewlett-Packard Development Company, L.P.
    Inventor: Alexandre Bratkovski
  • Patent number: 7397370
    Abstract: An assembly for monitoring an environment includes a RFID tag and at least one sensor assembly. The sensor assembly is configured to sense information regarding the environment around the assembly and convert a sensed event into power to at least partially power operation of the RFID tag.
    Type: Grant
    Filed: March 1, 2005
    Date of Patent: July 8, 2008
    Assignee: Hewlett-Packard Development Company, L.P.
    Inventor: Alexandre Bratkovski
  • Publication number: 20080102319
    Abstract: A composite material exhibiting at least one of a negative effective permittivity and a negative effective permeability for incident radiation at an operating wavelength is described. The composite material comprises a dielectric layer generally parallel to a dielectric layer plane, and further comprises a first plurality of nanowire pairs disposed in the dielectric layer. Each of the first plurality of nanowire pairs comprises substantially parallel conductive nanowires of short length and separation relative to the operating wavelength. Each of the first plurality of nanowire pairs is substantially coplanar with a first plane substantially parallel to the dielectric layer plane.
    Type: Application
    Filed: October 13, 2006
    Publication date: May 1, 2008
    Inventors: Alexandre Bratkovski, Shih-Yuan Wang, Ekaterina V. Ponizovskaya
  • Publication number: 20080087973
    Abstract: A composite material for providing at least one of a negative effective permeability and a negative effective permittivity for incident radiation of at least one wavelength is described. The composite material comprises a plurality of three-dimensional resonant cells disposed across a first substrate. Each three-dimensional resonant cell comprises a base substantially parallel to the substrate and at least three sidewalls upwardly extending therefrom. Each upwardly extending sidewall comprising a sidewall substrate having at least one conductor patterned thereon. Each upwardly extending sidewall is fabricated by forming the sidewall substrate as a substantially horizontal layer above the first substrate, lithographically patterning the sidewall substrate with the at least one conductor while horizontally disposed above the first substrate, and tilting up the sidewall substrate to the upwardly extending position.
    Type: Application
    Filed: October 12, 2006
    Publication date: April 17, 2008
    Inventors: Shih-Yuan Wang, Alexandre Bratkovski, Wei Wu
  • Publication number: 20080089645
    Abstract: Dispersion compensation for an optical signal having a first frequency range is described. The optical signal is applied to a dispersion compensating material having a negatively refracting behavior within the first frequency range. The dispersion compensating material is tuned by application of a control signal that varies at least one characteristic of the dispersion compensating material associated with the negatively refracting behavior.
    Type: Application
    Filed: October 12, 2006
    Publication date: April 17, 2008
    Inventors: Shih-Yuan Wang, Alexandre Bratkovski
  • Publication number: 20080088524
    Abstract: A composite material comprising a dielectric material and a plurality of non-overlapping local resonant cell groups disposed across the dielectric material is described. Each local resonant cell group comprises a plurality of resonant cells that are small relative to a first wavelength of electromagnetic radiation that is incident upon the composite material. Each local resonant cell group has a spatial extent that is not larger than an order of the first wavelength. For each of the local resonant cell groups, the resonant cells therein are chirped with respect to at least one geometric feature thereof such that a plurality of different subsets of the resonant cells resonate for a respective plurality of wavelengths in a spectral neighborhood of the first wavelength. The composite material exhibits at least one of a negative effective permeability and a negative effective permittivity for each of the plurality of wavelengths in that spectral neighborhood.
    Type: Application
    Filed: October 12, 2006
    Publication date: April 17, 2008
    Inventors: Shih-Yuan Wang, Alexandre Bratkovski