Patents by Inventor Jeffrey R. Chen

Jeffrey R. Chen 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: 10228465
    Abstract: An apparatus for improving a pointing capability of an optical pointing system includes a star tracker attitude control system for maintaining an alignment between the optical pointing system and a target, a beam steering mirror controlled by the star tracker attitude control system to direct an optical signal to impinge on the target, a fixed optical assembly configured to direct a portion of the optical signal from the bean steering mirror into a field of view of a star tracker telescope of the star tracker attitude control system, and a detector array for detecting the portion of the optical signal superimposed over a location in a current star scene in the star tracker telescope field of view, where the star tracker attitude control system is configured to operate the beam steering mirror to maintain the optical signal on the target by maintaining the superimposed signal on the location in the star scene.
    Type: Grant
    Filed: June 14, 2017
    Date of Patent: March 12, 2019
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventors: Guangning Yang, Jeffrey R. Chen
  • Publication number: 20180364359
    Abstract: An apparatus for improving a pointing capability of an optical pointing system includes a star tracker attitude control system for maintaining an alignment between the optical pointing system and a target, a beam steering mirror controlled by the star tracker attitude control system to direct an optical signal to impinge on the target, a fixed optical assembly configured to direct a portion of the optical signal from the bean steering mirror into a field of view of a star tracker telescope of the star tracker attitude control system, and a detector array for detecting the portion of the optical signal superimposed over a location in a current star scene in the star tracker telescope field of view, where the star tracker attitude control system is configured to operate the beam steering mirror to maintain the optical signal on the target by maintaining the superimposed signal on the location in the star scene.
    Type: Application
    Filed: June 14, 2017
    Publication date: December 20, 2018
    Inventors: Guangning Yang, Jeffrey R. Chen
  • Patent number: 10148352
    Abstract: An apparatus for measuring a distance between a first and second terminal includes a frame counter for determining a number of data frames traversing a distance between the first terminal 105 and the second terminal, a frame bit counter for determining a number of data clock bits offset between a transmitted data frame and a concurrently received data frame, a data clock phase detector for determining a phase difference between an RF data clock for the transmitted data frame and an RF data clock for the concurrently received data frame, and an optical carrier phase detector for determining a phase difference between an optical carrier used to transmit the transmitted data frame and an optical carrier for the concurrently received data frame. The distance between the first and second terminal is determined from a round trip transit time T between the first and second terminals.
    Type: Grant
    Filed: July 11, 2017
    Date of Patent: December 4, 2018
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventors: Guangning Yang, Jeffrey R. Chen
  • Patent number: 9964699
    Abstract: Disclosed herein are systems and methods related to use of hollow core photonic crystal fibers. A system includes a tube and a collimating lens configured in a first end of the tube, wherein a single mode fiber is coupled to a first end of the collimating lens. A second lens is supported by a structure at a second end of the tube, the second lens receiving a first signal from a second end of the collimating lens and outputting a second signal that is coupled into a first end of a hollow core photonic crystal fiber. A first gas tube is configured to introduce gas through the structure into a chamber and a sealant seals at least one of the collimating lens and the structure within the tube. An output signal is received at a detector that catches the entire beam to suppress multiple-mode beating noise.
    Type: Grant
    Filed: September 21, 2015
    Date of Patent: May 8, 2018
    Assignee: The United States of America, as represented by the Administrator of the National Aeronautics and Space Administraion
    Inventors: Jeffrey R. Chen, Kenji Numata, Stewart T. Wu
  • Publication number: 20160327735
    Abstract: Disclosed herein are systems and methods related to use of hollow core photonic crystal fibers. A system includes a tube and a collimating lens configured in a first end of the tube, wherein a single mode fiber is coupled to a first end of the collimating lens. A second lens is supported by a structure at a second end of the tube, the second lens receiving a first signal from a second end of the collimating lens and outputting a second signal that is coupled into a first end of a hollow core photonic crystal fiber. A first gas tube is configured to introduce gas through the structure into a chamber and a sealant seals at least one of the collimating lens and the structure within the tube. An output signal is received at a detector that catches the entire beam to suppress multiple-mode beating noise.
    Type: Application
    Filed: September 21, 2015
    Publication date: November 10, 2016
    Inventors: JEFFREY R. CHEN, KENJI NUMATA, STEWART T. WU
  • Patent number: 9065242
    Abstract: An apparatus and method is provided to enable precision and fast laser frequency tuning. For instance, a fast tunable slave laser may be dynamically offset-locked to a reference laser line using an optical phase-locked loop. The slave laser is heterodyned against a reference laser line to generate a beatnote that is subsequently frequency divided. The phase difference between the divided beatnote and a reference signal may be detected to generate an error signal proportional to the phase difference. The error signal is converted into appropriate feedback signals to phase lock the divided beatnote to the reference signal. The slave laser frequency target may be rapidly changed based on a combination of a dynamically changing frequency of the reference signal, the frequency dividing factor, and an effective polarity of the error signal. Feed-forward signals may be generated to accelerate the slave laser frequency switching through laser tuning ports.
    Type: Grant
    Filed: May 17, 2012
    Date of Patent: June 23, 2015
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics Space Administration
    Inventors: Jeffrey R. Chen, Kenji Numata, Stewart T. Wu, Guangning Yang
  • Publication number: 20130308663
    Abstract: An apparatus and method is provided to enable precision and fast laser frequency tuning. For instance, a fast tunable slave laser may be dynamically offset-locked to a reference laser line using an optical phase-locked loop. The slave laser is heterodyned against a reference laser line to generate a beatnote that is subsequently frequency divided. The phase difference between the divided beatnote and a reference signal may be detected to generate an error signal proportional to the phase difference. The error signal is converted into appropriate feedback signals to phase lock the divided beatnote to the reference signal. The slave laser frequency target may be rapidly changed based on a combination of a dynamically changing frequency of the reference signal, the frequency dividing factor, and an effective polarity of the error signal. Feed-forward signals may be generated to accelerate the slave laser frequency switching through laser tuning ports.
    Type: Application
    Filed: May 17, 2012
    Publication date: November 21, 2013
    Inventors: JEFFREY R. CHEN, Kenji Numata, Stewart T. Wu, Guangning Yang
  • Patent number: 7830527
    Abstract: A pulsed laser system includes a modulator module configured to provide pulsed electrical signals and a plurality of solid-state seed sources coupled to the modulator module and configured to operate, responsive to the pulsed electrical signals, in a pulse mode. Each of the plurality of solid-state seed sources is tuned to a different frequency channel separated from any adjacent frequency channel by a frequency offset. The pulsed laser system also includes a combiner that combines outputs from each of the solid state seed sources into a single optical path and an optical doubler and demultiplexer coupled to the single optical path and providing each doubled seed frequency on a separate output path.
    Type: Grant
    Filed: April 14, 2008
    Date of Patent: November 9, 2010
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventor: Jeffrey R. Chen
  • Publication number: 20090051926
    Abstract: A pulsed laser system includes a modulator module configured to provide pulsed electrical signals and a plurality of solid-state seed sources coupled to the modulator module and configured to operate, responsive to the pulsed electrical signals, in a pulse mode. Each of the plurality of solid-state seed sources is tuned to a different frequency channel separated from any adjacent frequency channel by a frequency offset. The pulsed laser system also includes a combiner that combines outputs from each of the solid state seed sources into a single optical path and an optical doubler and demultiplexer coupled to the single optical path and providing each doubled seed frequency on a separate output path.
    Type: Application
    Filed: April 14, 2008
    Publication date: February 26, 2009
    Applicant: United States of America as represented by the Administrator of the National Aeronautics and Spac
    Inventor: Jeffrey R. Chen