Search Patents
  • Buried channel charge coupled device with semi-insulating substrate
    Patent number: 4285000
    Abstract: A charge coupled device has a semi-insulating semiconductor for a substrate. Resistivity of the semiconductor is at least 10.sup.6 ohm cm. A semi-conductive layer is grown epitaxially or is implanted on the substrate to form a thin, active, charge transport layer. A row of parallel, closely spaced gates on the charge transport layer provides individual storage wells in the charge transport layer. In a preferred embodiment, ohmic contacts adjacent the first and last gates in the row of gates provide a means for injecting a signal into the charge transport layer and a means for detecting the signal. Preferably, the substrate is semi-insulating GaAs and the gates are Schottky barrier gates.
    Type: Grant
    Filed: March 12, 1979
    Date of Patent: August 18, 1981
    Assignee: Rockwell International Corporation
    Inventors: Ira Deyhimy, Richard C. Eden, James S. Harris, Jr., Lucia O. Bubulac
  • Optical imaging system having an illumination source between object and image
    Patent number: 7504613
    Abstract: An optical imaging system having an optical source located between the object being imaged and the sensor is provided. Such positioning of the source enables provision of compact optical imaging systems. In particular, such systems can have image widths significantly larger than the object to sensor separation. The arrangement of source, imaging assembly and sensor is such that an image of the source is not formed at the sensor. Therefore, the effect of this source positioning on the image of the object at the sensor is a reduction of intensity, as opposed to more objectionable imaging artifacts, such as spurious shadows and/or bright spots. Thus compact optical imaging systems having good image quality are provided, which enables high-fidelity imaging of object to sensor for a wide variety of applications.
    Type: Grant
    Filed: March 11, 2005
    Date of Patent: March 17, 2009
    Assignee: The Board of Trustees of the Leland Stanford Junior University
    Inventors: Evan Thrush, Jonathan Ziebarth, James S. Harris, Jr., Michael D. McGehee
  • Surface parallel modulator
    Publication number: 20080232735
    Abstract: SiGe quantum wells where the well material has a lowest conduction band energy minimum at k=0 (the ? point of the first Brillouin zone) are provided. Quantum well structures that satisfy this condition have “Kane-like” bands at and near k=0 which can provide physical effects useful for various device applications, especially optical modulators. In the Si1-xGex material system, this condition on the band structure is satisfied for x greater than about 0.7. The quantum well barrier composition may or may not have Kane-like bands. Embodiments of the invention having a surface parallel configuration are especially suitable for use in fiber coupled devices. Such surface parallel devices have light propagating in the plane of the quantum wells, in a device geometry that is preferably not single-mode waveguided.
    Type: Application
    Filed: September 19, 2006
    Publication date: September 25, 2008
    Inventors: David A.B. Miller, Yu-Hsuan Kuo, James S. Harris
  • Light emitting device for optical communications
    Patent number: 4110661
    Abstract: A high-speed, light emitting device which utilizes a solid state source for generating light for use in fiber optical communications. The source is an active, narrow band gap layer of semiconductive material between heterojunctions formed with a p.sup.+ -type material on one side of an n.sup.+ -type material on the other side. A mirror on the back of the source reflects light toward an optical fiber abutting the substrate on the front of the source. A side mirror traverses the edge of the active layer at an angle of about 45.degree. and reflects light traveling parallel to the active layer toward the optical fiber. Contacts are coupled to the semiconductor material for applying an electrical signal across the active layer to generate light. In a preferred embodiment, the active layer is GaAsSb joined to GaAlAsSb and the substrate is GaAs.
    Type: Grant
    Filed: April 1, 1977
    Date of Patent: August 29, 1978
    Assignee: Rockwell International Corporation
    Inventors: James S. Harris, Jr., Richard C. Eden, Earl S. Cory, Fred W. Scholl
  • Multiple GaInNAs quantum wells for high power applications
    Patent number: 7645626
    Abstract: In connection with an optical-electronic semiconductor device, improved photoluminescent output is provided at wavelengths approaching and beyond 1.3 ?m. According to one aspect, a multiple quantum well strain compensated structure is formed using a GaInNAs-based quantum well laser diode with GaNAs-based barrier layers. By growing tensile-strained GaNAs barrier layers, a larger active region with multiple quantum wells can be formed increasing the optical gain of the device. In example implementations, both edge emitting laser devices and vertical cavity surface emitting laser (VCSEL) devices can be grown with at least several quantum wells, for example, nine quantum wells, and with room temperature emission approaching and beyond 1.3 ?m.
    Type: Grant
    Filed: December 30, 2004
    Date of Patent: January 12, 2010
    Assignee: The Board of Trustees of the Leland Stanford Junior University
    Inventors: Wonill Ha, Vincent Gambin, James S. Harris
  • Semiconductor structures using a group III-nitride material system with reduced phase separation and method of fabrication
    Patent number: 7391062
    Abstract: Group III-nitride quaternary and pentenary material systems and methods are disclosed for use in semiconductor structures, including laser diodes, transistors, and photodetectors, which reduce or eliminate phase separation and provide increased emission efficiency. In an exemplary embodiment the semiconductor structure includes a first ternary, quaternary or pentenary material layer using BInGaAlN material system of a first conduction type formed substantially without phase separation, and a quaternary or pentenary material active layer using BInGaAlN material system substantially without phase separation, and a third ternary, quaternary or pentenary material layer using BInGaAlN material system of an opposite conduction type formed substantially without phase separation.
    Type: Grant
    Filed: March 8, 2005
    Date of Patent: June 24, 2008
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Toru Takayama, Takaaki Baba, James S. Harris, Jr.
  • Implantable sensing arrangement and approach
    Patent number: 8306607
    Abstract: Characteristics of biological substances, such as cerebral cortex matter, are sensed. According to an example embodiment, the present invention is directed to a negligibly-intrusive, multi-layer integrated circuit arrangement for monitoring activity of an area of a cerebral cortex that would normally be covered by an anatomical layer. The multi-layer integrated circuit arrangement includes an optics layer located outside the cerebral cortex area that includes an emitter and a detector. The optics layer is adapted for implantation in the anatomical layer and for sensing at least one brain-activity parameter. The multi-layered integrated circuit arrangement also includes a data-processing layer that includes a digital-processing circuit that is adapted for assimilating neural data in response to the optics layer sensing at least one brain-activity parameter.
    Type: Grant
    Filed: November 1, 2004
    Date of Patent: November 6, 2012
    Assignee: The Board of Trustees of the Leland Stanford Junior University
    Inventors: Ofer Levi, Evan P. Thrush, James S. Harris, Stepehn J. Smith, Krishna V. Shenoy
  • Low temperature grown optical detector
    Patent number: 6653706
    Abstract: A high efficiency optical interconnect (OI) deposited directly on a silicon based IC by a low temperature process that utilizes a heterogeneous crystalline structure of a III-V compound material to convert light pulses into electrical signals. The high efficiency is established by pulsing the light beams with a shorter duration than the life time of the generated carriers and by reducing the structural volume and consequently the internal capacitance of the III-V compound to a functional height of approximately 1 micron. The analog MSM characteristic of the OI is bypassed by differential two-beam signal processing, wherein the intensity difference of two synchronous light beams is transformed in two parallel OI's into two electrical signals that compensate in a central node. The resulting polarity in the node switches either a PMOS or a NMOS transistor, which connect either a positive or negative voltage to the output node.
    Type: Grant
    Filed: May 8, 2000
    Date of Patent: November 25, 2003
    Assignee: The Board of Trustees of the Leland Stanford Junior University
    Inventors: David A. B. Miller, James S. Harris, Jr.
  • Temperature-controlled optical modulator
    Patent number: 7515776
    Abstract: SiGe quantum wells where the well material has a lowest conduction band energy minimum at k=0 (the ? point of the first Brillouin zone) are provided. Quantum well structures that satisfy this condition have “Kane-like” bands at and near k=0 which can provide physical effects useful for various device applications, especially optical modulators. In the Si1-xGex material system, this condition on the band structure is satisfied for x greater than about 0.7. The quantum well barrier composition may or may not have Kane-like bands. Optical modulators including such SiGe quantum wells can be operated at temperatures other than room temperature. Such temperature control is preferred for providing optical modulators that operate in the telecommunication C band (˜1530 nm to ˜1565 nm).
    Type: Grant
    Filed: September 19, 2006
    Date of Patent: April 7, 2009
    Assignee: The Board of Trustees of the Leland Stanford Junior University
    Inventors: David A. B. Miller, James S. Harris, Jr., Yu-Hsuan Kuo
  • Silicon-based Ge/SiGe optical interconnects
    Patent number: 7515777
    Abstract: SiGe quantum wells where the well material has a lowest conduction band energy minimum at k=0 (the ? point of the first Brillouin zone) are provided. Quantum well structures that satisfy this condition have “Kane-like” bands at and near k=0 which can provide physical effects useful for various device applications, especially optical modulators. In the Si1-xGex material system, this condition on the band structure is satisfied for x greater than about 0.7. The quantum well barrier composition may or may not have Kane-like bands. Optical modulators and/or detectors according to the invention are suitable for inclusion in waveguide-based optical interconnects. Such interconnects can be on-chip interconnects or chip to chip interconnects.
    Type: Grant
    Filed: September 19, 2006
    Date of Patent: April 7, 2009
    Assignee: The Board of Trustees of the Leland Stanford Junior University
    Inventors: Yu-Hsuan Kuo, James S. Harris, Jr., David A. B. Miller
  • Production of diffraction limited holographic images
    Patent number: 4478481
    Abstract: An apparatus for the production of a holographic image of a subject disposed at a subject plane includes a source of coherent light divided by a beamsplitter into a reference beam and a subject beam. The subject beam is directed towards the subject through a beamsplitter and a quarter-wave plate. The front surface of an opaque subject or a mirror behind a transparent subject reflects the subject beam back through the quarter-wave plate to the beamsplitter where it is deflected towards a photo-sensitive recording medium through an imaging lens. The reference beam is simultaneously directed toward the recording medium at a predetermined angle of incidence. After exposure and development of the medium, it is illuminated from the conjugate direction by the redirected reference beam. Image rays exactly retrace their original paths back through the optical system and provide a three-dimensional real-image reconstruction at the subject plane.
    Type: Grant
    Filed: February 12, 1982
    Date of Patent: October 23, 1984
    Assignee: University of Dayton
    Inventors: Richard L. Fusek, James S. Harris, Kevin G. Harding
  • Surface parallel modulator
    Patent number: 7457487
    Abstract: SiGe quantum wells where the well material has a lowest conduction band energy minimum at k=0 (the ? point of the first Brillouin zone) are provided. Quantum well structures that satisfy this condition have “Kane-like” bands at and near k=0 which can provide physical effects useful for various device applications, especially optical modulators. In the Si1-xGex material system, this condition on the band structure is satisfied for x greater than about 0.7. The quantum well barrier composition may or may not have Kane-like bands. Embodiments of the invention having a surface parallel configuration are especially suitable for use in fiber coupled devices. Such surface parallel devices have light propagating in the plane of the quantum wells, in a device geometry that is preferably not single-mode waveguided.
    Type: Grant
    Filed: September 19, 2006
    Date of Patent: November 25, 2008
    Assignee: The Board of Trustees of the Leland Stanford Junior University
    Inventors: David A. B. Miller, Yu-Hsuan Kuo, James S. Harris, Jr.
  • Ge-Si quantum well structures
    Patent number: 7599593
    Abstract: Si—Ge quantum wells where the well material has a lowest conduction band energy minimum at k=0 (the ? point of the first Brillouin zone) are provided. Quantum well structures that satisfy this condition have “Kane-like” bands at and near k=0 which can provide physical effects useful for various device applications, especially optical modulators. In the Si1?xGex material system, this condition on the band structure is satisfied for x greater than about 0.7. The quantum well barrier composition may or may not have Kane-like bands. A preferred method of providing such quantum well structures on a substrate (e.g., a silicon substrate) is to grow a first Ge-rich Si—Ge buffer layer on the substrate, and then anneal the resulting layered structure. In many cases it is further preferred to grow a second Ge-rich Si—Ge buffer layer on top of the first buffer layer and anneal the resulting layered structure.
    Type: Grant
    Filed: September 19, 2005
    Date of Patent: October 6, 2009
    Assignee: The Board of Trustees of the Leland Stanford Junior University
    Inventors: James S. Harris, Jr., David A. B. Miller, Yu-Hsuan Kuo
  • Dynamic optical grating device
    Patent number: 5222071
    Abstract: The invention relates to an apparatus including a semiconductor grating whose optical properties can be changed electrically in order to steer a diffracted laser beam with no moving parts. Lithographically defined portions, stripes or areas formed in a semiconductor quantum well region used in association with selectable voltage supply means enable control of the optical characteristics of the grating. The optical properties of the semiconductor quantum well region vary in response to variations in voltage applied to the areas which in turn change the transmissivity or reflectivity of the areas. By selectively applying voltages, the diffraction pattern obtained in the far-field from illuminating the areas is thus controlled and beam steering results. By using a two-dimensional array of areas, or alternatively using two such one dimensional arrays, beam steering in two dimensions may be accomplished.
    Type: Grant
    Filed: February 21, 1991
    Date of Patent: June 22, 1993
    Assignee: Board of Trustees Leland Stanford, Jr. University
    Inventors: Bardia Pezeshki, James S. Harris, Jr.
  • Wavelength tunable narrow linewidth resonant cavity light detectors
    Patent number: 6380531
    Abstract: A light detector comprising a photodetector disposed within an etalon or microcavity. The light detector is sensitive to light having a wavelength resonant with the etalon. Preferably, the etalon is a solid state microcavity having distributed bragg reflectors. The photodetector may be a photodiode, phototransistor or the like. The etalon has a front reflector with reflectivity Rf and a back reflector with reflectivity Rb. The photodetector has a double-pass absorption of A. In the present invention, Rf, Rb, and A are selected such that Rf=Rb(1−A). The combination of the back reflector and absorbing photodetector is indistinguishable from a single reflector of reflectivity Rf. Therefore, the light detector behaves like an etalon with matched reflectors. Preferably, Rf is greater than 0.95 and Rb is greater than 0.98. The photodetector can have a relatively thin absorption layer, thereby providing high speed capability.
    Type: Grant
    Filed: November 30, 1999
    Date of Patent: April 30, 2002
    Assignee: The Board of Trustees of The Leland Stanford Junior University
    Inventors: Fred Sugihwo, James S. Harris, Jr.
  • (110) GaAs microwave FET
    Patent number: 4939557
    Abstract: A field effect transistor (FET) structure suitable for use at microwave frequencies is fabricated on a planar surface of a semi-insulating single crystal GaAs substrate which has been cut and polished to present the (110) surface. This orientation is selected because of its non-polar and other unique surface and interface properties. The (110) crystal axis is tilted from the normal of the planar surface in the direction to expose more of the (111) Ga face about 5.degree. to facilitate molecular beam epitaxial (MBE) growth of smooth, defect-free thin films. An elongate gate electrode is formed along the bottom of an anisotropically etched trench having a pair of longitudinal sidewalls, one vertical and the other tilted outwardly. The trench is selectively oriented on the substrate to facilitate such anisotropic etching.
    Type: Grant
    Filed: February 15, 1989
    Date of Patent: July 3, 1990
    Assignee: Varian Associates, Inc.
    Inventors: Yi-Ching Pao, James S. Harris
  • Optical modulator and optical modulator array
    Patent number: 5909303
    Abstract: A reversible and conservative photon routing switch is implemented as a room temperature, optical, vertical cavity X-gate (also sometimes known as a Fredkin gate). Such gates are primitive structures into which all logic functions can be decomposed. The construction of the device makes it uniquely suited to dense packed arrays of optoelectronic components for optical routing and logic. In one of the switching states, light incident on the device from either side of the wafer will pass through the device (the device is bi-directionally transmissive). In the other switching state, light incident from either side of the wafer will be reflected. Switching can be performed using either electrical or optical control. Thus incident photons are either routed through the device or reflected from the device.
    Type: Grant
    Filed: January 3, 1997
    Date of Patent: June 1, 1999
    Assignee: The Board of Trustees of the Leland Stanford Junior University
    Inventors: John A. Trezza, Martin Morf, James S. Harris
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