Patents by Inventor Serge Dubovitsky

Serge Dubovitsky 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: 6788420
    Abstract: The present invention relates to a heterodyne interferometer system with a pre-processing of the target signal to isolate and remove self-interference signals using a known phase modulation of the carrier signal's frequency. Where self-interference signals do not include a time delay inherent in the target signal that travels to the target reflector, by selecting a modulation frequency tuned to the time delay and then filtering the resultant signal the target beam can be isolated and the self-interference signal can be effectively removed The system includes a modulation unit to apply a phase modulation to the carrier signal, and a mixing unit that demodulates the target signal at the modulation frequency to isolate the target beam.
    Type: Grant
    Filed: January 29, 2002
    Date of Patent: September 7, 2004
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventor: Serge Dubovitsky
  • Patent number: 6753992
    Abstract: A method for suppressing distortion in a multi-wavelengths system which uses a Mach Zehnder optical modulator includes adjusting an internal path length mismatch of the modulator and changing an applied voltage, Vb, such that the combination biases the modulator to the required &pgr;/2 phase bias.
    Type: Grant
    Filed: June 14, 2002
    Date of Patent: June 22, 2004
    Assignee: Pacific Wave Industries, Inc.
    Inventors: William H. Steier, Serge Dubovitsky, Harold R. Fetterman, Joseph Michael
  • Publication number: 20030231372
    Abstract: A method for suppressing distortion in a multi-wavelengths system which uses a Mach Zehnder optical modulator includes adjusting an internal path length mismatch of the modulator and changing an applied voltage, Vb, such that the combination biases the modulator to the required &pgr;/2 phase bias.
    Type: Application
    Filed: June 14, 2002
    Publication date: December 18, 2003
    Inventors: William H. Steier, Serge Dubovitsky, Harold R. Fetterman, Joseph Michael
  • Patent number: 6646723
    Abstract: The present invention is an improved distance measuring interferometer that includes high speed phase modulators and additional phase meters to generate and analyze multiple heterodyne signal pairs with distinct frequencies. Modulation sidebands with large frequency separation are generated by the high speed electro-optic phase modulators, requiring only a single frequency stable laser source and eliminating the need for a first laser to be tuned or stabilized relative to a second laser. The combination of signals produced by the modulated sidebands is separated and processed to give the target distance. The resulting metrology apparatus enables a sensor with submicron accuracy or better over a multi-kilometer ambiguity range.
    Type: Grant
    Filed: May 7, 2002
    Date of Patent: November 11, 2003
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventors: Serge Dubovitsky, Oliver P. Lay
  • Publication number: 20020037025
    Abstract: The present invention is a method and apparatus for creating a narrow linewidth hybrid semiconductor laser using silicon-oxide and silicone-oxynitride based external feedback elements. These feedback elements use Bragg gratings formed by periodic variation of the refractive index with a resonate optical reflector. The laser has a narrow linewidth (in the tens of kHz range), which can be accurately tunable to facilitate locking to an ultra-stable cavity.
    Type: Application
    Filed: September 25, 2001
    Publication date: March 28, 2002
    Inventors: Randall K. Bartman, Alexander Ksendzov, Serge Dubovitsky