Patents by Inventor Tien-Hsin Chao

Tien-Hsin Chao 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: 9413461
    Abstract: A method, systems, apparatus and device enable high bandwidth satellite communications. An onboard tracking detector, installed in a low-earth orbit satellite, detects a position of an incoming optical beam received/transmitted from a first ground station of one or more ground stations. Tracker electronics determine orientation information of the incoming optical beam based on the position. Control electronics receive the orientation information from the tracker electronics, and control a waveguide drive electronics. The waveguide drive electronics control a voltage that is provided to an electro-optic waveguide beam steering device. The electro-optic waveguide beam steering device steers an outgoing optical beam to one of the one or more ground stations based on the voltage.
    Type: Grant
    Filed: November 4, 2014
    Date of Patent: August 9, 2016
    Assignee: California Institute of Technology
    Inventors: Tien-Hsin Chao, Keith E. Wilson, Keith Coste
  • Publication number: 20150125157
    Abstract: A method, systems, apparatus and device enable high bandwidth satellite communications. An onboard tracking detector, installed in a low-earth orbit satellite, detects a position of an incoming optical beam received/transmitted from a first ground station of one or more ground stations. Tracker electronics determine orientation information of the incoming optical beam based on the position. Control electronics receive the orientation information from the tracker electronics, and control a waveguide drive electronics. The waveguide drive electronics control a voltage that is provided to an electro-optic waveguide beam steering device. The electro-optic waveguide beam steering device steers an outgoing optical beam to one of the one or more ground stations based on the voltage.
    Type: Application
    Filed: November 4, 2014
    Publication date: May 7, 2015
    Applicant: CALIFORNIA INSTITUTE OF TECHNOLOGY
    Inventors: Tien-Hsin Chao, Keith E. Wilson, Keith Coste
  • Patent number: 7787165
    Abstract: A holographic memory system and apparatus, and a method provide the ability to store multibit holograms in a photorefractive crystal. A single laser diode is configured to emit a collimated laser beam to both write a page of multibit data to and read the page of multibit data from the photorefractive crystal. A multilevel spatial light modulator (DMDSLM) is configured to encode the page of multibit data on an input beam split from the collimated laser beam. A first imaging relay lens pair is positioned between the multilevel spatial light modulator and the photorefractive crystal to image a multibit spatial light modulator image on a plane behind the photorefractive crystal. One or more mirrors are configured to steer a reference beam, split from the collimated laser beam, at high speed to the photorefractive crystal to read or write a page of the multi-bit data.
    Type: Grant
    Filed: November 15, 2006
    Date of Patent: August 31, 2010
    Assignee: California Institute of Technology
    Inventor: Tien-Hsin Chao
  • Patent number: 7639363
    Abstract: An Electro-Optic Imaging Fourier Transform Spectrometer (EOIFTS) for Hyperspectral Imaging is described. The EOIFTS includes an input polarizer, an output polarizer, and a plurality of birefringent phase elements. The relative orientations of the polarizers and birefringent phase elements can be changed mechanically or via a controller, using ferroelectric liquid crystals, to substantially measure the spectral Fourier components of light propagating through the EIOFTS. When achromatic switches are used as an integral part of the birefringent phase elements, the EIOFTS becomes suitable for broadband applications, with over 1 micron infrared bandwidth.
    Type: Grant
    Filed: September 7, 2006
    Date of Patent: December 29, 2009
    Assignee: California Institute of Technology
    Inventors: Tien-Hsin Chao, Hanying Znod
  • Patent number: 7490941
    Abstract: The present invention relates to a three-dimensional (3D) hologram display system. The 3D hologram display system includes a projector device for projecting an image upon a display medium to form a 3D hologram. The 3D hologram is formed such that a viewer can view the holographic image from multiple angles up to 360 degrees. Multiple display media are described, namely a spinning diffusive screen, a circular diffuser screen, and an aerogel. The spinning diffusive screen utilizes spatial light modulators to control the image such that the 3D image is displayed on the rotating screen in a time-multiplexing manner. The circular diffuser screen includes multiple, simultaneously-operated projectors to project the image onto the circular diffuser screen from a plurality of locations, thereby forming the 3D image. The aerogel can use the projection device described as applicable to either the spinning diffusive screen or the circular diffuser screen.
    Type: Grant
    Filed: August 30, 2005
    Date of Patent: February 17, 2009
    Assignee: California Institute of Technology
    Inventors: Frederick Mintz, Tien-Hsin Chao, Nevin Bryant, Peter Tsou
  • Publication number: 20070211322
    Abstract: A holographic memory system and apparatus, and a method provide the ability to store multibit holograms in a photorefractive crystal. A single laser diode is configured to emit a collimated laser beam to both write a page of multibit data to and read the page of multibit data from the photorefractive crystal. A multilevel spatial light modulator (DMDSLM) is configured to encode the page of multibit data on an input beam split from the collimated laser beam. A first imaging relay lens pair is positioned between the multilevel spatial light modulator and the photorefractive crystal to image a multibit spatial light modulator image on a plane behind the photorefractive crystal. One or more mirrors are configured to steer a reference beam, split from the collimated laser beam, at high speed to the photorefractive crystal to read or write a page of the multi-bit data.
    Type: Application
    Filed: November 15, 2006
    Publication date: September 13, 2007
    Inventor: Tien-Hsin Chao
  • Publication number: 20070188838
    Abstract: We have designed, built and operated an innovative JTOC system utilizing a holographic photopolymer as the square law detector to record the holographic data for one-step correlation signal requisition in real time. The resultant high-resolution, high-speed JTOC is useful to perform real-time pattern recognition. An example application that has been demonstrated is fingerprint verification.
    Type: Application
    Filed: January 17, 2007
    Publication date: August 16, 2007
    Applicant: California Institute of Technology
    Inventors: Tien-Hsin Chao, J. Cammack
  • Patent number: 7251066
    Abstract: A method, apparatus, and system provide the ability for storing holograms at high speed. A single laser diode emits a collimated laser beam to both write to and read from a photorefractice crystal. One or more liquid crystal beam steering spatial light modulators (BSSLMs) steer a reference beam, split from the collimated laser beam, at high speed to the photorefractive crystal.
    Type: Grant
    Filed: August 4, 2006
    Date of Patent: July 31, 2007
    Assignee: California Institute of Technology
    Inventors: Tien-Hsin Chao, Jay C. Hanan, George F. Reyes, Hanying Zhou
  • Publication number: 20070070354
    Abstract: An Electro-Optic Imaging Fourier Transform Spectrometer (EOIFTS) for Hyperspectral Imaging is described. The EOIFTS includes an input polarizer, an output polarizer, and a plurality of birefringent phase elements. The relative orientations of the polarizers and birefringent phase elements can be changed mechanically or via a controller, using ferroelectric liquid crystals, to substantially measure the spectral Fourier components of light propagating through the EIOFTS. When achromatic switches are used as an integral part of the birefringent phase elements, the EIOFTS becomes suitable for broadband applications, with over 1 micron infrared bandwidth.
    Type: Application
    Filed: September 7, 2006
    Publication date: March 29, 2007
    Inventors: Tien-Hsin Chao, Hanying Znod
  • Patent number: 7149014
    Abstract: A method, apparatus, and system provide the ability for storing holograms at high speed. A single laser diode emits a collimated laser beam to both write to and read from a photorefractice crystal. One or more liquid crystal beam steering spatial light modulators (BSSLMs) or Micro-Electro-Mechanical Systems (MEMS) mirrors steer a reference beam, split from the collimated laser beam, at high speed to the photorefractive crystal.
    Type: Grant
    Filed: April 15, 2004
    Date of Patent: December 12, 2006
    Assignee: California Institute of Technology
    Inventors: Tien-Hsin Chao, Jay C. Hanan, George F. Reyes, Hanying Zhou
  • Publication number: 20060268380
    Abstract: A method, apparatus, and system provide the ability for storing holograms at high speed. A single laser diode emits a collimated laser beam to both write to and read from a photorefractice crystal. One or more liquid crystal beam steering spatial light modulators (BSSLMs) steer a reference beam, split from the collimated laser beam, at high speed to the photorefractive crystal.
    Type: Application
    Filed: August 4, 2006
    Publication date: November 30, 2006
    Applicant: CALIFORNIA INSTITUTE OF TECHNOLOGY
    Inventors: TIEN-HSIN CHAO, JAY HANAN, GEORGE REYES, HANYING ZHOU
  • Publication number: 20060171008
    Abstract: The present invention relates to a three-dimensional (3D) hologram display system. The 3D hologram display system includes a projector device for projecting an image upon a display medium to form a 3D hologram. The 3D hologram is formed such that a viewer can view the holographic image from multiple angles up to 360 degrees. Multiple display media are described, namely a spinning diffusive screen, a circular diffuser screen, and an aerogel. The spinning diffusive screen utilizes spatial light modulators to control the image such that the 3D image is displayed on the rotating screen in a time-multiplexing manner. The circular diffuser screen includes multiple, simultaneously-operated projectors to project the image onto the circular diffuser screen from a plurality of locations, thereby forming the 3D image. The aerogel can use the projection device described as applicable to either the spinning diffusive screen or the circular diffuser screen.
    Type: Application
    Filed: August 30, 2005
    Publication date: August 3, 2006
    Inventors: Frederick Mintz, Tien-Hsin Chao, Nevin Bryant, Peter Tsou
  • Publication number: 20040263924
    Abstract: A method, apparatus, and system provide the ability for storing holograms at high speed. A single laser diode emits a collimated laser beam to both write to and read from a photorefractice crystal. One or more liquid crystal beam steering spatial light modulators (BSSLMs) or Micro-Electro-Mechanical Systems (MEMS) mirrors steer a reference beam, split from the collimated laser beam, at high speed to the photorefractive crystal.
    Type: Application
    Filed: April 15, 2004
    Publication date: December 30, 2004
    Applicant: California Institute of Technology
    Inventors: Tien-Hsin Chao, Jay C. Hanan, George F. Reyes, Hanying Zhou
  • Patent number: 6529614
    Abstract: A Hybrid Optoelectronic Neural Object Recognition System (HONORS), is disclosed, comprising two major building blocks: (1) an advanced grayscale optical correlator (OC) and (2) a massively parallel three-dimensional neural-processor. The optical correlator, with its inherent advantages in parallel processing and shift invariance, is used for target of interest (TOI) detection and segmentation. The three-dimensional neural-processor, with its robust neural learning capability, is used for target classification and identification. The hybrid optoelectronic neural object recognition system, with its powerful combination of optical processing and neural networks, enables real-time, large frame, automatic target recognition (ATR).
    Type: Grant
    Filed: August 4, 1999
    Date of Patent: March 4, 2003
    Assignee: California Institute of Technology
    Inventors: Tien-Hsin Chao, Taher Daud, Anikumar Thakoor
  • Patent number: 6195184
    Abstract: A real-time, dynamic, free space-virtual reality, 3-D image display system which is enabled by using a unique form of Aerogel as the primary display media. A preferred embodiment of this system comprises a 3-D mosaic topographic map which is displayed by fusing four projected hologram images. In this embodiment, 4 holographic images are projected from 4 separate holograms. Each holographic image subtends a quadrant of the 4&pgr; solid angle. By fusing these four holographic images, a static 3-D image such as a featured terrain map would be visible for 360 degrees in the horizontal plane and 180 degrees in the vertical plane. An input, either acquired by 3-D image sensor or generated by computer animation, is first converted into a 2-D computer generated hologram (CGH). This CGH is then downloaded into large liquid crystal (LC) panel. A laser projector illuminates the CGH-filled LC panel and generates and displays a real 3-D image in the Aerogel matrix.
    Type: Grant
    Filed: June 19, 1999
    Date of Patent: February 27, 2001
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventors: Tien-Hsin Chao, Frederick W. Mintz, Peter Tsou, Nevin A. Bryant
  • Patent number: 5376807
    Abstract: A new type of optical correlator performs motion detection or background clutter suppression and correlation simultaneously in a single photorefractive crystal, and is useful for moving target identification and tracking and for stationary clutter rejection. The correlation is of the VanderLugt type and the motion detection or background clutter suppression is based on the erasing property of photorefractive crystals.
    Type: Grant
    Filed: April 7, 1993
    Date of Patent: December 27, 1994
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventors: Tsuen-Hsi Liu, Tien-Hsin Chao, Li-Jen Cheng
  • Patent number: 5263096
    Abstract: The opto-electronic morphological processor of the present invention is capable of receiving optical inputs and emitting optical outputs. The use of optics allows implementation of parallel input/output, thereby overcoming a major bottleneck in prior art image processing systems. The processor consists of three components, namely, detectors, morphological operators and modulators. The detectors and operators are fabricated on a silicon VLSI chip and implement the optical input and morphological operations. A layer of ferro-electric liquid crystals is integrated with a silicon chip to provide the optical modulation. The implementation of the image processing operators in electronics leads to a wide range of applications and the use of optical connections allows cascadability of these parallel opto-electronic image processing components and high speed operation. Such an opto-electronic morphological processor may be used as the pre-processing stage in an image recognition system.
    Type: Grant
    Filed: April 1, 1991
    Date of Patent: November 16, 1993
    Assignee: California Institute of Technology
    Inventors: Jeffrey W. Yu, Tien-Hsin Chao, Li J. Cheng, Demetri Psaltis
  • Patent number: 5262979
    Abstract: An associative optical memory including an input SLM in the form of an edge enhanced LCLV and a pair of memory SLMs in the form of LCTVs forms a matrix array of an input image which is cross correlated with a matrix array of stored images. The correlation product is detected and non-linearly amplified to illuminate a replica of the stored image array to select the stored image correlating with the input image. The LCLV is edge enhanced by reducing the bias frequency and voltage and rotating its orientation. The edge enhancement and non-linearity of the photodetection improves the orthogonality of the stored images. The illumination of the replicate stored image provides a clean stored image, uncontaminated by the image comparison process.
    Type: Grant
    Filed: August 19, 1991
    Date of Patent: November 16, 1993
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventor: Tien-Hsin Chao
  • Patent number: 5216484
    Abstract: An improved AOTF-based imaging spectrometer that has ability to electronically set the bandpass wavelength of an AOTF to any desired value in its wide tuning range, provides significant observational flexibility. This allows observations to be tailored in real-time and enables the spectrometer to address a wide range of objectives and permits real-time modification of the observational parameters, such as in flight or in other situations in which only remote control is possible. Various improvements in optical architecture provide simplified magnification variability, improved image resolution and light throughput efficiency and reduced sensitivity to ambient light. A preferred embodiment employs a camera zoom lens as the input lens. A TeO.sub.2 AOTF and a relay lens are placed at selected distances behind the back focal plane of the input lens, respectively.
    Type: Grant
    Filed: December 9, 1991
    Date of Patent: June 1, 1993
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventors: Tien-Hsin Chao, Li-Jen Cheng Cheng, Jeffrey W. Yu, James L. Lambert
  • Patent number: 5131055
    Abstract: An optical system for auto-associative and hetero-associative recall utilizing Hamming distance as the similarity measure between a binary input image vector V.sup.(k) and a binary image vector V.sup.(m) in a first memory array using an optical Exclusive-OR gate for multiplication of each of a plurality of different binary image vectors in memory by the input image vector. After integrating the light of each product V.sup.(k) .times.V.sup.(m), a shortest Hamming distance detection electronics module determines which product has the lowest light intensity and emits a signal that activates a light emitting diode to illuminate a corresponding image vector in a second memory array for display. That corresponding image vector is identical to the memory image vector V.sup.(m) in the first memory array for auto-associative recall or related to it, such as by name, for hetero-associative recall.
    Type: Grant
    Filed: February 16, 1990
    Date of Patent: July 14, 1992
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventor: Tien-Hsin Chao