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).
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Patent number: 11258514Abstract: 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: GrantFiled: July 9, 2021Date of Patent: February 22, 2022Assignee: BLUE CUBED, LLCInventors: Jonathan C. Twichell, Ryan W. Kingsbury, Scott E. Palo
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Publication number: 20220014274Abstract: 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: ApplicationFiled: July 9, 2021Publication date: January 13, 2022Inventors: Jonathan C. Twichell, Ryan W. Kingsbury, Scott E. Palo
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Patent number: 7091530Abstract: 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: GrantFiled: July 2, 2003Date of Patent: August 15, 2006Assignee: Massachusetts Institute of TechnologyInventors: Robert K. Reich, Bernard B. Kosicki, Jonathan C. Twichell, Barry E. Burke, Dennis D. Rathman
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Patent number: 6028424Abstract: 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: GrantFiled: April 6, 1999Date of Patent: February 22, 2000Assignee: Massachuetts Institute of TechnologyInventors: Jonathan C. Twichell, Roger J. Helkey
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Patent number: 5990604Abstract: 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: GrantFiled: February 2, 1998Date of Patent: November 23, 1999Assignee: Massacusetts Institute of TechnologyInventors: Michael W. Geis, Jonathan C. Twichell, Theodore M. Lyszczarz, Nickolay N. Efremow
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Patent number: 5973451Abstract: 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: GrantFiled: February 4, 1997Date of Patent: October 26, 1999Assignee: Massachusetts Institute of TechnologyInventors: Michael W. Geis, Nickolai N. Efremow, Kevin E. Krohn, Jonathan C. Twichell, Theodore M. Lyszczarz
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Patent number: 5955875Abstract: 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: GrantFiled: January 31, 1997Date of Patent: September 21, 1999Assignee: Massachusetts Institute of TechnologyInventors: Jonathan C. Twichell, Roger J. Helkey
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Patent number: 5900301Abstract: 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: GrantFiled: January 3, 1997Date of Patent: May 4, 1999Assignees: 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
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Patent number: 5728435Abstract: 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: GrantFiled: May 22, 1995Date of Patent: March 17, 1998Assignees: Candescent Technologies Corporation, Massachusetts Institute of TechnologyInventors: Michael W. Geis, John M. Macaulay, Jonathan C. Twichell
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Patent number: 5729094Abstract: 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: GrantFiled: April 15, 1996Date of Patent: March 17, 1998Assignee: Massachusetts Institute of TechnologyInventors: Michael W. Geis, Jonathan C. Twichell, Theodore M. Lyszczarz
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Patent number: 5713775Abstract: 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: GrantFiled: May 2, 1995Date of Patent: February 3, 1998Assignee: Massachusetts Institute of TechnologyInventors: Michael W. Geis, Jonathan C. Twichell, Theodore M. Lyszczarz, Nickolay N. Efremow
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Patent number: 5666025Abstract: 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: GrantFiled: October 17, 1995Date of Patent: September 9, 1997Assignee: Candescent Technologies CorporationInventors: Michael W. Geis, John M. Macaulay, Jonathan C. Twichell
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Patent number: 5608283Abstract: 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: GrantFiled: June 29, 1994Date of Patent: March 4, 1997Assignee: Candescent Technologies CorporationInventors: Jonathan C. Twichell, George R. Brandes, Michael W. Geis, John M. Macaulay, Robert M. Duboc, Jr., Christopher J. Curtin
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Patent number: 5463271Abstract: 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: GrantFiled: July 9, 1993Date of Patent: October 31, 1995Assignees: Silicon Video Corp., Massachusetts Institute of TechnologyInventors: Michael W. Geis, John M. Macaulay, Jonathan C. Twichell