Patents by Inventor Ernest G. Burkhardt

Ernest G. Burkhardt 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).

  • Buried undercut mesa-like waveguide and method of making same
    Patent number: 4764246
    Abstract: Epitaxial regrowth by vapor phase epitaxy of controlled composition semiconductor material in and around undercut regions of a processed heterostructure wafer permits formation of a ridge waveguide capable of active or passive operation. Subsequent material selective and crystallographically preferential etching is employed to form mirror facets on each end of the ridge waveguide.
    Type: Grant
    Filed: August 20, 1987
    Date of Patent: August 16, 1988
    Assignee: American Telephone and Telegraph Company, AT&T Bell Laboratories
    Inventors: Thomas J. Bridges, Ernest G. Burkhardt, Larry A. Coldren, Thomas L. Koch
  • Buried undercut mesa-like waveguide
    Patent number: 4725112
    Abstract: Epitaxial regrowth by vapor phase epitaxy of controlled composition semiconductor material in and around undercut regions of a processed heterostructure wafer permits formation of a ridge waveguide capable of active or passive operation. Subsequent material selective and crystallographically preferential etching is employed to form mirror facets on each end of the ridge waveguide.
    Type: Grant
    Filed: August 6, 1985
    Date of Patent: February 16, 1988
    Assignee: American Telephone and Telegraph Company, AT&T Bell Laboratories
    Inventors: Thomas J. Bridges, Ernest G. Burkhardt, Larry A. Coldren, Thomas L. Koch
  • Spectrophone with field tuning of absorption cell
    Patent number: 4105919
    Abstract: The spectrophone, in which a gas containing an impurity in an absorption cell is illuminated by an optical beam that is modulated at an acoustic frequency, has an output pressure response at the acoustic frequency in accordance with the concentration of the impurity in the gas. This output is tuned by a magnetic (or electric) field applied to the absorption cell, while the optical wavelength is kept constant. The Zeeman (or Stark) effect of the impurity can thus be used to tune the absorption process of the impurity to a maximum response.
    Type: Grant
    Filed: April 25, 1977
    Date of Patent: August 8, 1978
    Assignee: Bell Telephone Laboratories, Incorporated
    Inventors: Thomas J. Bridges, Ernest G. Burkhardt