Patents by Inventor Michael W. Geis

Michael W. Geis 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: 11275868
    Abstract: An improved waveguide is disclosed. The waveguide utilizes a luminescent material disposed within or around its perimeter to introduce additional light into the waveguide. For example, the waveguide may include a plurality of planar layers having different refractive indexes. A luminescent material may be disposed along the outer edge of these layers. When light from within the waveguide strikes the luminescent material, it emits light, thereby adding to the light in the waveguide. Not only does the luminescent material introduce more light into the waveguide, it also introduces more light sources, thereby making it more difficult to introduce a probe without blocking at least a portion of the light destined for the image sensor. The luminescent material may be a phosphor.
    Type: Grant
    Filed: July 1, 2020
    Date of Patent: March 15, 2022
    Assignee: Massachusetts Institute of Technology
    Inventors: Michael W. Geis, Joshua Kramer, Karen M. G. V. Gettings, Marc J. Burke, Mankuan M. Vai, Theodore M. Lyszczarz
  • Publication number: 20210012034
    Abstract: An improved waveguide is disclosed. The waveguide utilizes a luminescent material disposed within or around its perimeter to introduce additional light into the waveguide. For example, the waveguide may include a plurality of planar layers having different refractive indexes. A luminescent material may be disposed along the outer edge of these layers. When light from within the waveguide strikes the luminescent material, it emits light, thereby adding to the light in the waveguide. Not only does the luminescent material introduce more light into the waveguide, it also introduces more light sources, thereby making it more difficult to introduce a probe without blocking at least a portion of the light destined for the image sensor. The luminescent material may be a phosphor.
    Type: Application
    Filed: July 1, 2020
    Publication date: January 14, 2021
    Inventors: Michael W. Geis, Joshua Kramer, Karen M.G.V. Gettings, Marc J. Burke, Mankuan M. Vai, Theodore M. Lyszczarz
  • Patent number: 10740493
    Abstract: An improved waveguide is disclosed. The waveguide utilizes a luminescent material disposed within or around its perimeter to introduce additional light into the waveguide. For example, the waveguide may include a plurality of planar layers having different refractive indexes. A luminescent material may be disposed along the outer edge of these layers. When light from within the waveguide strikes the luminescent material, it emits light, thereby adding to the light in the waveguide. Not only does the luminescent material introduce more light into the waveguide, it also introduces more light sources, thereby making it more difficult to introduce a probe without blocking at least a portion of the light destined for the image sensor. The luminescent material may be a phosphor.
    Type: Grant
    Filed: February 29, 2016
    Date of Patent: August 11, 2020
    Assignee: Massachusetts Institute of Technology
    Inventors: Michael W. Geis, Joshua Kramer, Karen M.G.V. Gettings, Marc J. Burke, Mankuan M. Vai, Theodore M. Lyszczarz
  • Publication number: 20180212026
    Abstract: New compositions of matter and device constructs are disclosed in the form of diamond material layers or films having one or more surfaces treated with chemically active radicals, e.g., photo-radical or thermal-radical generators to reduce and stabilize their surface resistance. The compositions exhibit stable, markedly lower surface resistances, e.g., below about 3 k? sq?1 or between about 3 and 2 k? sq?1 or below 2 k? sq?1, or below 1 k? sq?1, or lower. In certain embodiments, the diamond material is a epitaxial layer grown on a substrate, e.g., by microwave plasma chemical vapor deposition (CVD) and can have a thickness ranging from about 1 nm to 1 mm, preferably from about 10 nm to 500 ?m, or from about 100 nm to 10 ?m. The invention also encompasses semiconductor devices fabricated from the surface-modified diamond materials disclosed herein.
    Type: Application
    Filed: November 28, 2017
    Publication date: July 26, 2018
    Inventors: Theodore H. Fedynyshyn, Michael W. Geis, Mark A. Hollis
  • Publication number: 20180026801
    Abstract: An improved waveguide is disclosed. The waveguide comprises four or five layers, an inner core polymer, one or two layers of outer cladding polymer either on one side of the core of sandwiching the inner core polymer, and two layers of a dielectric reflector sandwiching the outer cladding polymer. The refractive index of the inner core polymer is greater than that of the outer cladding polymer. Further, the refractive index of the outer cladding polymer is greater than that of the dielectric reflector. Further, the waveguide can be used to create a physically unclonable function. A light source and an image sensor may be disposed on a printed circuit board. The waveguide may be disposed on the printed circuit board so that light emitted from the light source traverses the waveguide before reaching the image sensor.
    Type: Application
    Filed: February 29, 2016
    Publication date: January 25, 2018
    Inventors: Michael W. Geis, Joshua I. Kramer, Karen M.G.V. Gettings, Marc J. Burke, Mankuan M. Vai
  • Publication number: 20180025182
    Abstract: An improved waveguide is disclosed. The waveguide utilizes a luminescent material disposed within or around its perimeter to introduce additional light into the waveguide. For example, the waveguide may include a plurality of planar layers having different refractive indexes. A luminescent material may be disposed along the outer edge of these layers. When light from within the waveguide strikes the luminescent material, it emits light, thereby adding to the light in the waveguide. Not only does the luminescent material introduce more light into the waveguide, it also introduces more light sources, thereby making it more difficult to introduce a probe without blocking at least a portion of the light destined for the image sensor. The luminescent material may be a phosphor.
    Type: Application
    Filed: February 29, 2016
    Publication date: January 25, 2018
    Inventors: Michael W. Geis, Joshua Kramer, Karen M.G.V. Gettings, Marc J. Burke, Mankuan M. Vai, Theodore M. Lyszczarz
  • Patent number: 8818150
    Abstract: Method and apparatus for modulation of both the intensity and the polarization of radiation in silicon waveguides by applying a biasing voltage to the waveguide.
    Type: Grant
    Filed: March 30, 2007
    Date of Patent: August 26, 2014
    Assignee: Massachusetts Institute of Technology
    Inventors: Matthew E. Grein, Theodore M. Lyszczarz, Michael W. Geis, Steven J. Spector, Donna M. Lennon, Yoon Jung
  • Patent number: 7880204
    Abstract: A Silicon photodetector contains an insulating substrate having a top surface and a bottom surface. A Silicon layer is located on the top surface of the insulating substrate, where the Silicon layer contains a center region, the center region being larger in thickness than the rest of the Silicon layer. A top Silicon dioxide layer is located on a top surface of the center region. A left wing of the center region and a right wing of the center region are doped. The Silicon photodetector also has an active region located within the center region, where the active region contains a tailored crystal defect-impurity combination and Oxygen atoms.
    Type: Grant
    Filed: October 2, 2006
    Date of Patent: February 1, 2011
    Assignee: Massachusetts Institute of Technology
    Inventors: Michael W. Geis, Steven J. Spector, Donna M. Lennon, Matthew E. Grein, Robert T. Schulein, Jung U. Yoon, Franz Xaver Kaertner, Fuwan Gan, Theodore M. Lyszczarz
  • Publication number: 20100025787
    Abstract: A Silicon photodetector contains an insulating substrate having a top surface and a bottom surface. A Silicon layer is located on the top surface of the insulating substrate, where the Silicon layer contains a center region, the center region being larger in thickness than the rest of the Silicon layer. A top Silicon dioxide layer is located on a top surface of the center region. A left wing of the center region and a right wing of the center region are doped. The Silicon photodetector also has an active region located within the center region, where the active region contains a tailored crystal defect-impurity combination and Oxygen atoms.
    Type: Application
    Filed: October 2, 2006
    Publication date: February 4, 2010
    Applicant: Massachusetts Institute of Technology
    Inventors: Michael W. Geis, Steven J. Spector, Donna M. Lennon, Matthew E. Grein, Robert T. Schulein, Jung U. Yoon, Franz Xaver Kaertner, Fuwan Gan, Theodore M. Lyszczarz
  • Patent number: 7443090
    Abstract: A surface-emission cathode formed on an insulating surface having cantilevered, i.e. “undercut,” electrodes. Suitable insulating surfaces include negative electron affinity (NEA) insulators such as glass or diamond. The cathode can operate in a comprised vacuum (e.g., 10?7 Torr) with no bias on the electrodes and low vacuum electric fields (e.g., at least 10 V cm?1). Embodiments of the present invention are inexpensive to fabricate, requiring lithographic resolution of approximately 10 micrometers. These cathodes can be formed over large areas for use in lighting and displays and are suitable for satellite applications, such as cathodes for tethers, thrusters and space-charging neutralizers.
    Type: Grant
    Filed: September 28, 2005
    Date of Patent: October 28, 2008
    Assignee: The Massachusetts Institute of Technology
    Inventors: Michael W. Geis, Theodore H. Fedynyshyn, Sandra J. Deneault, Keith E. Krohn, Theodore M. Lyszczarz, Michael F. Marchant
  • Patent number: 6833027
    Abstract: A method of making a Schottky diode comprising the steps of: providing a single crystal diamond comprising a surface; placing the single crystal diamond in a CVD system; heating the diamond to a temperature of at least about 950° C.; providing a gas mixture capable of growing diamond film and comprising a sulfur compound through the CVD system; growing an epitaxial diamond film on the surface of the single crystal diamond; baking the diamond at a temperature of at least about 650° C. in air for a period of time that minimizes oxidation of the diamond; and fabricating a Schottky diode comprising the diamond film. A Schottky diode comprising an epitaxial diamond film and capable of blocking at least about 6 kV in a distance of no more than about 300 &mgr;m.
    Type: Grant
    Filed: September 26, 2002
    Date of Patent: December 21, 2004
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventors: James E. Butler, Michael W. Geis, Donald D. Flechtner, Robert L. Wright
  • Publication number: 20030075100
    Abstract: A method of making a Schottky diode comprising the steps of: providing a single crystal diamond comprising a surface; placing the single crystal diamond in a CVD system; heating the diamond to a temperature of at least about 950° C.; providing a gas mixture capable of growing diamond film and comprising a sulfur compound through the CVD system; growing an epitaxial diamond film on the surface of the single crystal diamond; baking the diamond at a temperature of at least about 650° C. in air for a period of time that minimizes oxidation of the diamond; and fabricating a Schottky diode comprising the diamond film. A Schottky diode comprising an epitaxial diamond film and capable of blocking at least about 6 kV in a distance of no more than about 300 &mgr;m.
    Type: Application
    Filed: September 26, 2002
    Publication date: April 24, 2003
    Inventors: James E. Butler, Michael W. Geis, Donald D. Flechtner, Robert L. Wright
  • Patent number: 6413781
    Abstract: The method and apparatus of the invention create a dynamic Soret effect for propelling a target chemical constituent along a pathway. A moving temperature profile impressed upon the pathway produces consecutive alternating warmer and cooler zones along the path which transport components of a mixture down the path according to their respective diffusivities. In one embodiment, the invention provides a dynamic thermophoretic concentrator for separating a target chemical constituent from a mixture of components on the basis of diffusion coefficient by using alternate forward and backward motion of a temperature profile along the pathway, thereby accumulating an ultimate concentration of the target constituent greater than its initial concentration in the mixture.
    Type: Grant
    Filed: April 6, 1999
    Date of Patent: July 2, 2002
    Assignee: Massachusetts Institute of Technology
    Inventors: Michael W. Geis, Roderick R. Kunz, Margaret B. Stern
  • 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: 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: 5825240
    Abstract: Resonant-tunneling transmission lines in the various architectures rely on discrete or continuous resonant-tunneling heterostructures to actively modify propagating logic signals. One embodiment utilizes amplification of logic signals to counteract ubiquitous losses and distortion associated with any transmission medium. Basically, the logic signal is incrementally reamplified and reshaped as it propagates along the transmission line. Another embodiment is directed to a clocking system that transmits a signal represented by a sinusoid. Then, in proximity to the logic gates or modules, the sinusoid is converted into a square wave that actually clocks the gates and other logic structures. The inventive active transmission line naturally performs this feature, thus enabling clock signal transmission over longer links coupled with sinusoid-to-square wave conversion in a limited area. Still other embodiments implement step or continuous variations in the physical width of the resonant-tunneling transmission line.
    Type: Grant
    Filed: August 22, 1997
    Date of Patent: October 20, 1998
    Assignee: Massachusetts Institute of Technology
    Inventors: Michael W. Geis, Elliott R. Brown, Stephen J. Eglash, Christopher L. Dennis
  • 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