Patents by Inventor Francis A. Karwacki

Francis A. Karwacki 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: 6621836
    Abstract: A tunable Vertical Cavity Surface Emitting Laser (VCSEL) is disclosed that produces N frequencies of visible light. The VCSEL comprises an array of quantum wells (QWMs) which replaces one of the normally present Distributive Bragg Reflectors (DBR) at one end of a laser cavity of the VCSEL. These N independent QWMs produce N independent frequency in the laser cavity of the VCSEL device.
    Type: Grant
    Filed: March 29, 2001
    Date of Patent: September 16, 2003
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventor: Francis A. Karwacki
  • Publication number: 20020159490
    Abstract: A tunable Vertical Cavity Surface Emitting Laser (VCSEL) is disclosed that produces N frequencies of visible light. The VCSEL comprises an array of quantum wells (QWMs) which replaces one of the normally present Distributive Bragg Reflectors (DBR) at one end of a laser cavity of the VCSEL. These N independent QWMs produce N independent frequency in the laser cavity of the VCSEL device.
    Type: Application
    Filed: March 29, 2001
    Publication date: October 31, 2002
    Inventor: Francis A. Karwacki
  • Patent number: 5978141
    Abstract: An optical mirror comprised of a stack of film pairs of alternating layers f high and low indices of refraction materials is disclosed. The optical mirror may further comprise a non-polished substrate and provides the desired reflectivity for the use in the operation of a quantum well mirror that provides an optical bias for a ring laser gyroscope.
    Type: Grant
    Filed: November 17, 1997
    Date of Patent: November 2, 1999
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventor: Francis A. Karwacki
  • Patent number: 5058431
    Abstract: A superconducting Josephson junction gyroscope for detecting rotational motion of a vehicle about an axis. A persistent current of Cooper-paired electrons travels around a thin-film superconducting ring and the phase change across a Josephson junction in the ring produces an output signal directly proportional to the rate of rotation of the platform.
    Type: Grant
    Filed: May 23, 1990
    Date of Patent: October 22, 1991
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventor: Francis A. Karwacki
  • Patent number: 4544891
    Abstract: A nuclear magnetic resonance gyroscope which derives angular rotation thef from the phases of precessing nuclear moments utilizes a single-resonance cell situated in the center of a uniform DC magnetic field. The field is generated by current flow through a circular array of coils between parallel plates. It also utilizes a pump and readout beam and associated electronics for signal processing and control. Encapsulated in the cell for sensing rotation are odd isotopes of Mercury Hg.sup.199 and Hg.sup.201. Unpolarized intensity modulated light from a pump lamp is directed by lenses to a linear polarizer, quarter wave plate combination producing circularly polarized light. The circularly polarized light is reflected by a mirror to the cell transverse to the field for optical pumping of the isotopes. Unpolarized light from a readout lamp is directed by lenses to another linear polarizer.
    Type: Grant
    Filed: December 27, 1982
    Date of Patent: October 1, 1985
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventor: Francis A. Karwacki
  • Patent number: 4509014
    Abstract: A nuclear magnetic resonance gyroscope which derives angular rotation thef from the phases of precessing nuclear moments utilizes a single-resonance cell situated in the center of a uniform DC magnetic field. The field is generated by current flow through a circular array of coils between parallel plates. It also utilizes a pump and read-out beam and associated electronics for signal processing and control. Encapsulated in the cell for sensing rotation are odd isotopes of Mercury Hg.sup.199 and Hg.sup.201. Unpolarized intensity modulated light from a pump lamp is directed by lenses to a linear polarizer, quarter wave plate combination producing circularly polarized light. The circularly polarized light is reflected by a mirror to the cell transverse to the field for optical pumping of the isotopes. Unpolarized light from a readout lamp is directed by lenses to another linear polarizer.
    Type: Grant
    Filed: November 23, 1982
    Date of Patent: April 2, 1985
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventors: Francis A. Karwacki, Joseph Griffin