Patents by Inventor Jonathan C. Twichell

Jonathan C. Twichell 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).

  • Patent number: 11258514
    Abstract: A method for aligning a first optical transceiver includes steps of splitting, directing, recording, and actuating. The splitting step includes splitting a light beam into a) a reference beam that propagates along a common optical path within the first optical transceiver and b) a transmit beam that that propagates away from the first optical transceiver and toward a second optical transceiver. The directing step includes directing, with a beam director, a receive beam from the second optical transceiver onto the common optical path. The recording step includes recording, with a tracking focal-plane array (FPA) that intersects the common optical path, a reference-position of the reference beam and an initial-received-position of the receive beam on the tracking FPA. The actuating step includes actuating the beam director based upon the initial-received-position to achieve a subsequent position of the receive beam on the tracking FPA.
    Type: Grant
    Filed: July 9, 2021
    Date of Patent: February 22, 2022
    Assignee: BLUE CUBED, LLC
    Inventors: Jonathan C. Twichell, Ryan W. Kingsbury, Scott E. Palo
  • Publication number: 20220014274
    Abstract: A method for aligning a first optical transceiver includes steps of splitting, directing, recording, and actuating. The splitting step includes splitting a light beam into a) a reference beam that propagates along a common optical path within the first optical transceiver and b) a transmit beam that that propagates away from the first optical transceiver and toward a second optical transceiver. The directing step includes directing, with a beam director, a receive beam from the second optical transceiver onto the common optical path. The recording step includes recording, with a tracking focal-plane array (FPA) that intersects the common optical path, a reference-position of the reference beam and an initial-received-position of the receive beam on the tracking FPA. The actuating step includes actuating the beam director based upon the initial-received-position to achieve a subsequent position of the receive beam on the tracking FPA.
    Type: Application
    Filed: July 9, 2021
    Publication date: January 13, 2022
    Inventors: Jonathan C. Twichell, Ryan W. Kingsbury, Scott E. Palo
  • Patent number: 7091530
    Abstract: A charge-coupled device imager including an array of super pixels disposed in a semiconductor substrate having a surface that is accessible to incident illumination. For each super pixel there is provided a plurality of subpixels which each correspond to one in the sequence of image frames. Each subpixel includes a doped photogenerated charge collection channel region opposite the illumination-accessible substrate surface, a charge collection channel region control electrode, doped charge drain regions adjacent to the channel region, a charge drain region control electrode, and a doped charge collection control region. To each subpixel are provided channel region and drain region control voltage connections, for independent collection and storage of photogenerated charge from the substrate at the charge collection channel region of a selected subpixel during one in the sequence of image frames and for drainage of photogenerated charge from the substrate to a drain region.
    Type: Grant
    Filed: July 2, 2003
    Date of Patent: August 15, 2006
    Assignee: Massachusetts Institute of Technology
    Inventors: Robert K. Reich, Bernard B. Kosicki, Jonathan C. Twichell, Barry E. Burke, Dennis D. Rathman
  • Patent number: 6028424
    Abstract: A linearized optical sampler is described. The optical sampler includes an electro-optic modulator having an optical signal input, an electrical signal input, and at least two optical signal outputs that generate at least two modulated optical signals. The optical sampler also includes at least two detectors each of which being optically coupled to a respective one of the at least two modulated optical signals. Each detector generates an electrical signal in response to an optical intensity of the respective one of the at least two modulated optical signals. The optical sampler also includes a signal processor electrically connected to each of the at least two detectors. The signal processor applies an inverse transform of the modulator transfer function. The signal processor also generates an electrical signal from the electrical signals generated by the detectors and from the inverse transform that is linearly related to an RF signal electrically that is coupled to the electrical signal input.
    Type: Grant
    Filed: April 6, 1999
    Date of Patent: February 22, 2000
    Assignee: Massachuetts Institute of Technology
    Inventors: Jonathan C. Twichell, Roger J. Helkey
  • Patent number: 5990604
    Abstract: Improved field-emission devices are based on composing the back contact to the emitter material such that electron-injection efficiency into the emitter material is enhanced. Alteration of the emitter material structure near the contact or geometric field enhancement due to contact morphology gives rise to the improved injection efficiency. The devices are able to emit electrons at high current density and lower applied potential differences and temperatures than previously achieved. Wide-bandgap emitter materials without shallow donors benefit from this approach. The emission characteristics of diamond substitutionally doped with nitrogen, having a favorable emitter/vacuum band structure but being limited by the efficiency of electron injection into it, show especial improvement in the context of the invention.
    Type: Grant
    Filed: February 2, 1998
    Date of Patent: November 23, 1999
    Assignee: Massacusetts Institute of Technology
    Inventors: Michael W. Geis, Jonathan C. Twichell, Theodore M. Lyszczarz, Nickolay N. Efremow
  • Patent number: 5973451
    Abstract: The surface-emission cathodes of the invention are constructed so that the cathode body has a free surface over which electrons are efficiently accelerated after injection from a conductive contact. The junction between the free surface and the contact has the property that the height of the barrier to tunneling from the contact to floating surface states associated with the free surface of the cathode body is lower than both the barrier to emission from the contact to vacuum and the barrier to injection from the contact into the conduction band of the cathode body material. Thus under an applied potential, electrons are injected from the contact into floating surface states associated with the free surface. After acceleration, electrons leave the free surface, either emitted to vacuum or injected into another medium.
    Type: Grant
    Filed: February 4, 1997
    Date of Patent: October 26, 1999
    Assignee: Massachusetts Institute of Technology
    Inventors: Michael W. Geis, Nickolai N. Efremow, Kevin E. Krohn, Jonathan C. Twichell, Theodore M. Lyszczarz
  • Patent number: 5955875
    Abstract: A linearized optical sampler is described. The optical sampler includes an electro-optic modulator having an optical signal input, an electrical signal input, and at least two optical signal outputs that generate at least two modulated optical signals. The optical sampler also includes at least two detectors each of which being optically coupled to a respective one of the at least two modulated optical signals. Each detector generates an electrical signal in response to an optical intensity of the respective one of the at least two modulated optical signals. The optical sampler also includes a signal processor electrically connected to each of the at least two detectors. The signal processor applies an inverse transform of the modulator transfer function. The signal processor also generates an electrical signal from the electrical signals generated by the detectors and from the inverse transform that is linearly related to an RF signal electrically that is coupled to the electrical signal input.
    Type: Grant
    Filed: January 31, 1997
    Date of Patent: September 21, 1999
    Assignee: Massachusetts Institute of Technology
    Inventors: Jonathan C. Twichell, Roger J. Helkey
  • Patent number: 5900301
    Abstract: Fabrication of an electron-emitting device entails distributing electron-emissive carbon-containing particles (22) over a non-insulating region (12). The particles can be made electron emissive after the particle distributing step. Particle bonding material (24) is typically provided to bond the particles to the non-insulating region. The particle bonding material can include carbide formed by heating or/and can be created by modifying a layer (32) provided between the non-insulating region and the particles. In one embodiment, the particles emit electrons primarily from graphite or/and amorphous carbon regions. In another embodiment, the particles are made electron-emissive prior to the particle distributing step.
    Type: Grant
    Filed: January 3, 1997
    Date of Patent: May 4, 1999
    Assignees: Candescent Technologies Corporation, Massachusetts Institute of Technology, Advanced Technology Materials, Inc.
    Inventors: George E. Brandes, Jonathan C. Twichell, Michael W. Geis, John M. Macaulay, Robert M. Duboc, Jr., Christopher J. Curtin
  • Patent number: 5728435
    Abstract: A cathode structure is formed by a process in which a carbon-containing electron-emissive cathode is subjected to electronegative atoms that include oxygen and/or fluorine. The cathode is also subjected to atoms of electropositive metal, typically after being subjected to the atoms of oxygen and/or fluorine. The combination of the electropositive metal atoms and the electronegative atoms enhances the electron emissivity by reducing the work function.
    Type: Grant
    Filed: May 22, 1995
    Date of Patent: March 17, 1998
    Assignees: Candescent Technologies Corporation, Massachusetts Institute of Technology
    Inventors: Michael W. Geis, John M. Macaulay, Jonathan C. Twichell
  • Patent number: 5729094
    Abstract: An energetic-electron emitter providing electrons having kinetic energies on the order of one thousand electron volts without acceleration through vacuum. An average electric field of 10.sup.5 V/m to 10.sup.10 V/m applied across a layer of emissive cathode material accelerates electrons inside the layer. The cathode material is a high-dielectric strength, rigid-structure, wide-bandgap semiconductors, especially type Ib diamond. A light-emitting device incorporates the energetic-electron emitter as a source of excitation to luminescence.
    Type: Grant
    Filed: April 15, 1996
    Date of Patent: March 17, 1998
    Assignee: Massachusetts Institute of Technology
    Inventors: Michael W. Geis, Jonathan C. Twichell, Theodore M. Lyszczarz
  • Patent number: 5713775
    Abstract: Improved field-emission devices are based on composing the back contact to the emitter material such that electron-injection efficiency into the emitter material is enhanced. Alteration of the emitter material structure near the contact or geometric field enhancement due to contact morphology gives rise to the improved injection efficiency. The devices are able to emit electrons at high current density and lower applied potential differences and temperatures than previously achieved. Wide-bandgap emitter materials without shallow donors benefit from this approach. The emission characteristics of diamond substitutionally doped with nitrogen, having a favorable emitter/vacuum band structure but being limited by the efficiency of electron injection into it, show especial improvement in the context of the invention.
    Type: Grant
    Filed: May 2, 1995
    Date of Patent: February 3, 1998
    Assignee: Massachusetts Institute of Technology
    Inventors: Michael W. Geis, Jonathan C. Twichell, Theodore M. Lyszczarz, Nickolay N. Efremow
  • Patent number: 5666025
    Abstract: A flat-panel display contains an emissive cathode structure and a generally flat encapsulating body that surrounds the cathode structure to form a sealed enclosure. The cathode structure contains electronegative atoms (22), which consist of oxygen and/or fluorine, chemically bonded to a carbon-containing cathode (10). Atoms (24R) of electropositive metal are chemically bonded to the electronegative atoms.
    Type: Grant
    Filed: October 17, 1995
    Date of Patent: September 9, 1997
    Assignee: Candescent Technologies Corporation
    Inventors: Michael W. Geis, John M. Macaulay, Jonathan C. Twichell
  • Patent number: 5608283
    Abstract: In one electron-emitting device, non-insulating particle bonding material (24) securely bonds electron-emissive carbon-containing particles (22) to an underlying non-insulating region (12). The carbon in each carbon-containing particle is in the form of diamond, graphite, amorphous carbon, or/and silicon carbide. In another electron-emitting device, electron-emissive pillars (22/28) overlie a non-insulating region (12). Each pillar is formed with an electron-emissive particle (22) and an underlying non-insulating pedestal (28).
    Type: Grant
    Filed: June 29, 1994
    Date of Patent: March 4, 1997
    Assignee: Candescent Technologies Corporation
    Inventors: Jonathan C. Twichell, George R. Brandes, Michael W. Geis, John M. Macaulay, Robert M. Duboc, Jr., Christopher J. Curtin
  • Patent number: 5463271
    Abstract: A cathode structure contains electronegative atoms (22), which consist of oxygen and/or fluorine, chemically bonded to a carbon-containing cathode (10). Atoms (24R) of electropositive metal are chemically bonded to the electronegative atoms. The combination of the electropositive metal atoms and the electronegative atoms enhances the electron emissivity by reducing the work function.
    Type: Grant
    Filed: July 9, 1993
    Date of Patent: October 31, 1995
    Assignees: Silicon Video Corp., Massachusetts Institute of Technology
    Inventors: Michael W. Geis, John M. Macaulay, Jonathan C. Twichell