Patents by Inventor Carlo Sirtori

Carlo Sirtori 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: 5457709
    Abstract: This application discloses, to the best of our knowledge, the first unipolar laser. An exemplary embodiment of the laser was implemented in the GaInAs/AlInAs system and emits radiation of about 4.2 .mu.m wavelength. Embodiments in other material systems are possible, and the lasers can be readily designed to emit at a predetermined wavelength in a wide spectral region. We have designated the laser the "quantum cascade" (QC) laser. The QC laser comprises a multilayer semiconductor structure that comprises a multiplicity of essentially identical undoper "active" regions, a given active region being separated from an adjoining one by a doped "energy relaxation" region. In a currently preferred embodiment each active region comprises three coupled quantum wells designed to facilitate attainment of population inversion. In the currently preferred embodiment the energy relaxation regions are digitally graded gap regions. However, other energy relaxation regions are possible.
    Type: Grant
    Filed: April 4, 1994
    Date of Patent: October 10, 1995
    Assignee: AT&T IPM Corp.
    Inventors: Federico Capasso, Alfred Y. Cho, Jerome Faist, Albert L. Hutchinson, Serge Luryi, Carlo Sirtori, Deborah L. Sivco
  • Patent number: 5311009
    Abstract: In accordance with the invention, a quantum well device provides localized states for electrons having an energy E greater than the barrier height of the constituent quantum wells. The device comprises a confinement quantum well of width L.sub.w equal to an integer number n of deBroglie half wavelengths ##EQU1## and a plurality of adjacent quarter wavelength barriers and wells, each having a thickness equal to an odd number m of deBroglie quarter wavelengths. Constructive interference between the waves partially reflected by the interfaces between adjacent .lambda./4 barriers and .lambda./4 wells leads to the formation of a localized electron state at an energy E in the region of the confinement well. The device can be used in detectors and modulators employing transitions between a bound state within the well and the localized state above the well.
    Type: Grant
    Filed: July 31, 1992
    Date of Patent: May 10, 1994
    Assignee: AT&T Bell Laboratories
    Inventors: Federico Capasso, Alfred Y. Cho, Jerome Faist, Carlo Sirtori, Deborah L. Sivco