Search Patents
  • Patent number: 6424763
    Abstract: A tunable electromagnetic field frequency filter having an input waveguide which carries a signal including at least one desired frequency, and an output waveguide. A resonator-system is coupled to the input and output waveguides and is operable for the selective transfer of the at least one desired frequency to the output waveguide. The resonator-system supports at least two system modes, and includes at least three reflectors with at least two different reflectivity spectra. At least one of the reflectivity spectra is tuned such that at least two of the system-modes have substantially the same frequency when the transfer occurs substantially.
    Type: Grant
    Filed: October 27, 2000
    Date of Patent: July 23, 2002
    Assignee: Massachusetts Institute of Technology
    Inventors: Pierre R. Villeneuve, Shanhui Fan, Gale S. Petrich, Leslie A. Kolodziejski, John D. Joannopoulos
  • Patent number: 6512866
    Abstract: A highly efficient channel drop filter. The filter employs a coupling element including a resonator-system between two waveguides, which contains at least two resonant modes. The resonator-system includes one or more interacting resonant cavities which in addition to being coupled to the waveguides, can also be coupled directly among themselves and indirectly among themselves via the waveguides. Each component of the coupling element can be configured or adjusted individually. The geometry and/or dielectric constant/refractive index of the resonator-system are configured so that the frequencies and decay rates of the resonant modes are made to be substantially the same. The filter can achieve 100% signal transfer between the waveguides at certain frequencies, while completely prohibiting signal transfer at other frequencies. In exemplary embodiments, the filter is configured with photonic crystals.
    Type: Grant
    Filed: July 20, 2000
    Date of Patent: January 28, 2003
    Assignee: Massachusetts Institute of Technology
    Inventors: Shanhui Fan, Pierre R. Villeneuve, John D. Joannopoulos, Brent E. Little, Hermann A. Haus
  • Patent number: 6101300
    Abstract: A highly efficient channel drop filter. The filter employs a coupling element including a resonator-system between two waveguides, which contains at least two resonant modes. The resonator-system includes one or more interacting resonant cavities which in addition to being coupled to the waveguides, can also be coupled directly among themselves and indirectly among themselves via the waveguides. Each component of the coupling element can be configured or adjusted individually. The geometry and/or dielectric constant/refractive index of the resonator-system are configured so that the frequencies and decay rates of the resonant modes are made to be substantially the same. The filter can achieve 100% signal transfer between the waveguides at certain frequencies, while completely prohibiting signal transfer at other frequencies. In exemplary embodiments, the filter is configured with photonic crystals.
    Type: Grant
    Filed: May 15, 1998
    Date of Patent: August 8, 2000
    Assignee: Massachusetts Institute of Technology
    Inventors: Shanhui Fan, Pierre R. Villeneuve, John D. Joannopoulos, Brent E. Little, Hermann A. Haus
  • Patent number: 6130969
    Abstract: A highly efficient channel drop filter. The filter employs a coupling element including a resonator-system between two waveguides, which contains at least two resonant modes. The resonator-system includes one or more interacting resonant cavities which in addition to being coupled to the waveguides, can also be coupled directly among themselves and indirectly among themselves via the waveguides. Each component of the coupling element can be configured or adjusted individually. The geometry and/or dielectric constant/refractive index of the resonator-system are configured so that the frequencies and decay rates of the resonant modes are made to be substantially the same. The filter can achieve 100% signal transfer between the waveguides at certain frequencies, while completely prohibiting signal transfer at other frequencies. In exemplary embodiments, the filter is configured with photonic crystals.
    Type: Grant
    Filed: November 12, 1997
    Date of Patent: October 10, 2000
    Assignee: Massachusetts Institute of Technology
    Inventors: Pierre R. Villeneuve, Shanhui Fan, John D. Joannopoulos, Hermann A. Haus
  • Patent number: 6198860
    Abstract: An optical waveguide structure including a first waveguide, a second waveguide that intersects with the first waveguide, and a photonic crystal resonator system at the intersection of the first and second waveguides. In accordance with another embodiment there is provided an optical waveguide crossing structure including a first waveguide that propagates signals in a first direction, a second waveguide that intersects with the first waveguide and propagates signals in a second direction, and a photonic crystal crossing region at the intersection of the first and second waveguides that prevents crosstalk between the signals of the first and second waveguides.
    Type: Grant
    Filed: September 22, 1998
    Date of Patent: March 6, 2001
    Assignee: Massachusetts Institute of Technology
    Inventors: Steven G. Johnson, Shanhui Fan, Pierre R. Villeneuve, Christina Manolatou, Hermann A. Haus, John D. Joannopoulos