Patents by Inventor Ruedeger Koehler

Ruedeger Koehler 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).

  • THz semiconductor laser incorporating a controlled plasmon confinement waveguide
    Patent number: 7382806
    Abstract: A semiconductor laser comprises an active region (12) which, in response to a pumping energy applied thereto, can produce a stimulated emission of radiation with a central wavelength (?) in the far infrared region, and a confinement region (16, 18, 22) suitable for confining the radiation in the active region (12), and comprising at least one interface (16a, 16b, 22a) between adjacent layers that is capable of supporting surface plasmon modes generated by an interaction of the interface with the radiation. The confinement region (16, 18, 22) comprises a wave-guide layer (16) which is delimited on opposite sides by a first interface and by a second interface (16a, 16b).
    Type: Grant
    Filed: March 24, 2003
    Date of Patent: June 3, 2008
    Assignee: INFM Istituto Nazionale per La Fisica Della Materia
    Inventors: Alessandro Tredicucci, Fabio Beltram, Harvey Edward Beere, Alexander Giles Davies, Ruedeger Koehler, Edmund Harold Linfield
  • Thz semiconductor laser incorporating a controlled plasmon confinement waveguide
    Publication number: 20050117618
    Abstract: A semiconductor laser comprises an active region (12) which, in response to a pumping energy applied thereto, can produce a stimulated emission of radiation with a central wavelength (?) in the far infrared region, and a confinement region (16, 18, 22) suitable for confining the radiation in the active region (12), and comprising at least one interface (16a, 16b, 22a) between adjacent layers that is capable of supporting surface plasmon modes generated by an interaction of the interface with the radiation. The confinement region (16, 18, 22) comprises a wave-guide layer (16) which is delimited on opposite sides by a first interface and by a second interface (16a, 16b).
    Type: Application
    Filed: March 24, 2003
    Publication date: June 2, 2005
    Inventors: Alessandro Tredicucci, Fabio Beltram, Ruedeger Koehler, Harvey, Edward Beere, Alexander, Giles Davies, Edmund, Harold Linfield
  • Apparatus comprising a quantum cascade laser having improved distributed feedback for single-mode operation
    Patent number: 6400744
    Abstract: An article comprising a QC-DFB laser is disclosed. In the QC-DFB laser, an overlying grating structure achieves relatively strong coupling of the guided mode to the grating, and is thus highly effective in inducing single-mode operation even under cw operating conditions. The grating structure includes grooves etched in a plasmon-enhanced confinement layer (PECL) disposed adjacent and in contact with an upper metallic electrode. The grating structure and the PECL are designed such that in the grooves, the laser mode travelling in the waveguide can couple efficiently to the surface-plasmon at the electrode interface. This results in strong modulation of the laser mode, leading to strong modulation of, inter alia, the effective refractive index.
    Type: Grant
    Filed: February 25, 2000
    Date of Patent: June 4, 2002
    Assignee: Lucent Technologies, Inc.
    Inventors: Federico Capasso, Alfred Yi Cho, Sung-Nee George Chu, Claire F. Gmachi, Ruedeger Koehler, Deborah Lee Sivco, Alessandro Tredicucci