Patents by Inventor Dennis M. Callahan

Dennis M. Callahan 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).

  • Publication number: 20190384221
    Abstract: SAW modulators are used as components of diffractive imaging systems. Arrays of the modulators can be used to detect the light field from a scene. In specific applications, they can be used to provide matched filtering for object recognition.
    Type: Application
    Filed: June 12, 2019
    Publication date: December 19, 2019
    Inventors: Gregg E. Favalora, Juha-Pekka Laine, Joseph J. Register, Dennis M. Callahan, Jr., Ian Ward Frank
  • Publication number: 20190302569
    Abstract: There can be a problem of output intensity node or nodes as a function of angle, for waveguide-based optical modulators, such as leaky-mode surface acoustic wave modulators. Several approaches are illustrated that can be used to provide more uniform output light across a range of angles, i.e., that is avoid dark “drop-outs.” It can also be used to increase the output angle range or exit light fan. This is achieved by leveraging the different diffraction characteristics between different guided modes. It exploits the observation that utilizing different waveguide guided modes, e.g. TE0 like versus TE1-like, causes a SAW optical modulator to operate with different relationships between output angle and output intensity. It turns out that they can be at least complementary, that is: one waveguide mode can fill in the dark gaps of another wave guide mode.
    Type: Application
    Filed: March 29, 2018
    Publication date: October 3, 2019
    Inventors: Gregg E. Favalora, Michael G. Moebius, Joy C. Perkinson, Dennis M. Callahan, Steven J. Byrnes, Ian W. Frank
  • Patent number: 10416468
    Abstract: Electro-holographic light field generator devices comprising surface acoustic wave (SAW) optical modulators are disclosed that employ multiple output couplers. These output couplers might be distributed along waveguides of the SAW modulators, within output coupling regions. Each of these output couplers can be configured for directing an incident leaky mode light at different output angles. In some cases, it may be desirable to employ the output couplers to function as different sub-pixels, to provide light to different viewing directions. The output couplers may be mirrors, volume gratings, chirped gratings, reflection gratings, two dimensional gratings, and/or transmission gratings. The output couplers may be angled so that the coupling output fans for each optical modulator are offset from the waveguide for that optical modulator.
    Type: Grant
    Filed: March 28, 2018
    Date of Patent: September 17, 2019
    Assignee: The Charles Stark Draper Laboratory, Inc.
    Inventors: Michael G. Moebius, Gregg E. Favalora, Joseph J. Register, Steven J. Byrnes, Ian W. Frank, Dennis M. Callahan
  • Patent number: 10156770
    Abstract: Packaging and interconnect systems for edge-emitting light modulators are disclosed. Embodiments address the challenge of integrating many edge-emitting modulators such as surface acoustic wave (SAW) modulators together in a single light field generator system. In one example, a proposed light field generator system includes a stack of projector modules and a mounting block having slots. The projector modules preferably have a printed circuit board (PCB) form factor that enables the slots of the mounting block to receive and hold the modules. Each module includes a module board and one or more SAW substrates carried by the module board, and an array of SAW modulators are formed/fabricated within each substrate. Proposed substrate fabrication techniques provide wiring and routing of RF and optical signals to the SAW modulators within each substrate to achieve a density of light modulators suitable for practical application to light field projection systems.
    Type: Grant
    Filed: February 8, 2018
    Date of Patent: December 18, 2018
    Assignee: The Charles Stark Draper Laboratory, Inc.
    Inventors: Gregg E. Favalora, Valerie J. Bloomfield, Hongmei Zhang, Anthony Kopa, Peter H. Lewis, Dennis M. Callahan, Joseph J. Register, Michael G. Moebius
  • Publication number: 20180341127
    Abstract: A system and method for improving spatial light modulator (SLM) devices such as Surface Acoustic Wave (SAW) modulators are disclosed. The SAW modulators can improved angular bandwidth and suppress unwanted diffractive orders. In one example, a coating layer(s) is applied to a proximal face of the SAW modulator to improve coupling of guided modes into leaky modes. Additionally, applying coating layers(s) such as a hybrid anti-reflective/highly reflective coating to an exit face of the SAW modulator can suppress transmission of undesired diffractive order(s).
    Type: Application
    Filed: May 25, 2018
    Publication date: November 29, 2018
    Inventors: Ian Ward Frank, Jeffrey A. Korn, Steven J. Byrnes, Dennis M. Callahan, JR.
  • Publication number: 20180329271
    Abstract: A system and method for a Surface Acoustic Wave (SAW) spatial light modulator module, or SAW device that provides varying acoustic wave speed are disclosed. The SAW device includes a substrate of a material such as lithium niobate, and a coating layer is applied to the substrate. A SAW transducer of the device is configured to produce SAW signals that propagate with a propagation velocity around an interface between the substrate and the coating layer. The SAW signals couple light signals of a light source into modulated light signals that are emitted from the bottom face and/or edge face of the substrate. In embodiments, a frequency of RF drive signals applied to the SAW transducer in conjunction with the propagation velocity of the SAW signals produces a decrease in a SAW wavelength of the SAW signals as compared to current SAW device systems and methods.
    Type: Application
    Filed: May 10, 2018
    Publication date: November 15, 2018
    Inventors: Ian Ward Frank, Dennis M. Callahan, JR., Steven J. Byrnes, Michael Gerhard Moebius, Gregg E. Favalora
  • Publication number: 20180284563
    Abstract: An electro-holographic light field generator device comprises surface acoustic wave (SAW) optical modulators arranged in different directions. Specifically, some embodiments have SAW modulators arranged in pairs, nose-to-nose with each other, and have output couplers that provide face-fire light emission. These SAW modulators also possibly include SAW sense transducers and/or viscoelastic surface material to reduce crosstalk.
    Type: Application
    Filed: March 28, 2018
    Publication date: October 4, 2018
    Inventors: Joseph J. Register, Dennis M. Callahan, Michael G. Moebius, Steven J. Byrnes, Gregg E. Favalora, Ian W. Frank
  • Publication number: 20180284562
    Abstract: An electro-holographic light field generator device comprises surface acoustic wave (SAW) optical modulators arranged in different directions. Specifically, some embodiments have SAW modulators arranged in pairs, nose-to-nose with each other, and have output couplers that provide face-fire light emission. These SAW modulators also possibly include SAW sense transducers and/or viscoelastic surface material to reduce crosstalk.
    Type: Application
    Filed: March 28, 2018
    Publication date: October 4, 2018
    Inventors: Joseph J. Register, Dennis M. Callahan, Michael G. Moebius, Steven J. Byrnes, Gregg E. Favalora, Ian W. Frank
  • Publication number: 20180284466
    Abstract: Electro-holographic light field generator devices comprising surface acoustic wave (SAW) optical modulators are disclosed that employ multiple output couplers. These output couplers might be distributed along waveguides of the SAW modulators, within output coupling regions. Each of these output couplers can be configured for directing an incident leaky mode light at different output angles. In some cases, it may be desirable to employ the output couplers to function as different sub-pixels, to provide light to different viewing directions. The output couplers may be mirrors, volume gratings, chirped gratings, reflection gratings, two dimensional gratings, and/or transmission gratings. The output couplers may be angled so that the coupling output fans for each optical modulator are offset from the waveguide for that optical modulator.
    Type: Application
    Filed: March 28, 2018
    Publication date: October 4, 2018
    Inventors: Michael G. Moebius, Gregg E. Favalora, Joseph J. Register, Steven J. Byrnes, Ian W. Frank, Dennis M. Callahan
  • Publication number: 20180217414
    Abstract: An electro-holographic light field generator device is disclosed. The light field generator device has an optical substrate with a waveguide face and an exit face. One or more surface acoustic wave (SAW) optical modulator devices are included within each light field generator device. The SAW devices each include a light input, a waveguide, and a SAW transducer, all configured for guided mode confinement of input light within the waveguide. A leaky mode deflection of a portion of the waveguided light, or diffractive light, impinges upon the exit face. Multiple output optics at the exit face are configured for developing from each of the output optics a radiated exit light from the diffracted light for at least one of the waveguides. An RF controller is configured to control the SAW devices to develop the radiated exit light as a three-dimensional output light field with horizontal parallax and compatible with observer vertical motion.
    Type: Application
    Filed: January 30, 2018
    Publication date: August 2, 2018
    Inventors: Steven J. Byrnes, Gregg E. Favalora, Joseph J. Register, Ian W. Frank, Dennis M. Callahan, Michael G. Moebius, Juha-Pekka J. Laine
  • Publication number: 20180217473
    Abstract: An electro-holographic light field generator device is disclosed. The light field generator device has an optical substrate with a waveguide face and an exit face. One or more surface acoustic wave (SAW) optical modulator devices are included within each light field generator device. The SAW devices each include a light input, a waveguide, and a SAW transducer, all configured for guided mode confinement of input light within the waveguide. A leaky mode deflection of a portion of the waveguided light, or diffractive light, impinges upon the exit face. Multiple output optics at the exit face are configured for developing from each of the output optics a radiated exit light from the diffracted light for at least one of the waveguides. An RF controller is configured to control the SAW devices to develop the radiated exit light as a three-dimensional output light field with horizontal parallax and compatible with observer vertical motion.
    Type: Application
    Filed: January 30, 2018
    Publication date: August 2, 2018
    Inventors: Ian W. Frank, Steven J. Byrnes, Juha-Pekka J. Laine, Gregg E. Favalora, Joseph J. Register, Dennis M. Callahan, Michael G. Moebius
  • Patent number: 9455146
    Abstract: A virtual substrate includes a handle support and a strain-relieved single crystalline layer on the handle support. A method of making the virtual substrate includes growing a coherently-strained single crystalline layer on an initial growth substrate, removing the initial growth substrate to relieve the strain on the single crystalline layer, and applying the strain-relieved single crystalline layer on a handle support.
    Type: Grant
    Filed: December 17, 2010
    Date of Patent: September 27, 2016
    Assignee: California Institute of Technology
    Inventors: Harry A. Atwater, Marina S. Leite, Emily C. Warmann, Dennis M. Callahan
  • Publication number: 20110193195
    Abstract: A virtual substrate includes a handle support and a strain-relieved single crystalline layer on the handle support. A method of making the virtual substrate includes growing a coherently-strained single crystalline layer on an initial growth substrate, removing the initial growth substrate to relieve the strain on the single crystalline layer, and applying the strain-relieved single crystalline layer on a handle support.
    Type: Application
    Filed: December 17, 2010
    Publication date: August 11, 2011
    Inventors: Harry A. Atwater, Marina S. Leite, Emily C. Warmann, Dennis M. Callahan