Patents by Inventor Joaquim Ferreira Martins-Filho

Joaquim Ferreira Martins-Filho 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).

  • Dual-wavelength pumped thulium-doped optical fiber amplifier
    Patent number: 7113328
    Abstract: An arrangement and method provide an optical thulium doped fiber amplifier utilizing a dual wavelength pumping scheme for amplifying an optical signal. The method includes the steps of: a first deposition (a) of energy into the fiber amplifier by pumping with radiation of a first wavelength; and a second deposition (b) of energy into the fiber amplifier by pumping with radiation of a second wavelength. The radiation of the first wavelength is arranged to induce, by single photon absorption, a population to the 3H4 level of the thulium dopant, and the radiation of the second wavelength primarily depopulates the 3F4 level, by excited absorption of a single photon, preferably by strong excited state absorption to the 3F2 level. The steps gives a population inversion between the 3H4 and the 3F4 levels and facilitate a power efficient high gain amplification.
    Type: Grant
    Filed: March 10, 2003
    Date of Patent: September 26, 2006
    Assignee: Telefonaktiebolaget LM Ericsson (publ)
    Inventors: Anderson Stevens Leonidas Gomes, Michael Lee Sundheimer, Mariana Torres Carvalho, Joaquim Ferreira Martins-Filho, Carmelo José Albanez Bastos-Filho, Walter Margulis
  • Methods and arrangements in a pumped fiber amplifier
    Publication number: 20030231380
    Abstract: An arrangement and method provide an optical thulium doped fiber amplifier utilizing a dual wavelength pumping scheme for amplifying an optical signal. The method includes the steps of: a first deposition (a) of energy into the fiber amplifier by pumping with radiation of a first wavelength; and a second deposition (b) of energy into the fiber amplifier by pumping with radiation of a second wavelength. The radiation of the first wavelength is arranged to induce, by single photon absorption, a population to the 3H4 level of the thulium dopant, and the radiation of the second wavelength primarily depopulates the 3F4 level, by excited absorption of a single photon, preferably by strong excited state absorption to the 3F2 level. The steps gives a population inversion between the 3H4 and the 3F4 levels and facilitate a power efficient high gain amplification.
    Type: Application
    Filed: March 10, 2003
    Publication date: December 18, 2003
    Inventors: Anderson Stevens Leonidas Gomes, Michael Lee Sundheimer, Mariana Torres Carvalho, Joaquim Ferreira Martins-Filho, Carmelo Jose Albanez Bastos-Filho, Walter Margulis