Search Patents
  • Effect of the plasmonic dispersion relation on the transmission properties of subwavelength holes
    Patent number: 7417219
    Abstract: Using a realistic plasmonic model, an optically thick electrically conductive film with subwavelength hole or holes therein is shown to always support propagating modes near the surface plasmon frequency, where cross-sectional dimensions of the hole or holes are less than about ?/2nh, ? being the wavelength of the light and nh the refractive index of the dielectric material in the hole or holes. This is the case even when material losses are taken into account. Based on the dispersion analysis, in both a single hole or hole array designs, propagating modes play a dominant role in the transport properties of incident light. These structures exhibit a new region of operation, while featuring a high packing density and diffraction-less behavior.
    Type: Grant
    Filed: September 20, 2006
    Date of Patent: August 26, 2008
    Assignee: The Board of Trustees of the Leland Stanford Junior University
    Inventors: Peter B. Catrysse, Hocheol Shin, Shanhui Fan
  • High efficiency channel drop filter with absorption induced on/off switching and modulation
    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
  • Ultra-slow down and storage of light pulses, and altering of pulse spectrum
    Patent number: 7269313
    Abstract: Light pulses can be stopped and stored coherently, with an all-optical process that involves an adiabatic and reversible pulse bandwidth compression occurring entirely in the optical domain. Such a process overcomes the fundamental bandwidth-delay constraint in optics, and can generate arbitrarily small group velocities for light pulses with a given bandwidth, without the use of any coherent or resonant light-matter interactions. This is accomplished only by small refractive index modulations performed at moderate speeds and has applications ranging from quantum communications and computing to coherent all-optical memory devices. A complete time reversal and/or temporal/spectral compression and expansion operation on any electromagnetic field is accomplished using only small refractive index modulations and linear optical elements.
    Type: Grant
    Filed: November 30, 2004
    Date of Patent: September 11, 2007
    Assignee: The Board of Trustees of the Leland Stanford Junior University
    Inventors: Mehmet Fatih Yanik, Shanhui Fan
  • Optical waveguide crossings
    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
  • Tunable polarization mode dispersion compensation using multi-layered reflector
    Publication number: 20030197936
    Abstract: We describe a novel approach for tunable polarization mode dispersion (PMD) compensation using multi-layered thin-film dielectric reflectors. This design can compensate for both the first-order PMD and the second-order PMD in ultrahigh speed optical fiber communication systems. Built-in cavity layers constitute optical resonators localizing electromagnetic energy at a specific frequency in the cavity region and therefore generating dispersive reflection. The two principal states of polarization in this system, TE and TM modes, demonstrate different dispersion responses for oblique incidences, which can be readily tuned to offset the PMD accumulated in fiber links. Various schemes of dispersion generation could be designed using single-cavity cascading or with coupled multiple-cavity resonator structures.
    Type: Application
    Filed: April 18, 2002
    Publication date: October 23, 2003
    Applicant: THE BOARD OF TRUSTEES OF THE LELAND STANFORD JUNIOR UNIVERSITY
    Inventors: Zhang Wang, David A.B. Miller, Shanhui Fan
  • High efficiency channel drop filter
    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
  • Input light coupler using a pattern of dielectric contrast distributed in at least two dimensions
    Patent number: 6574383
    Abstract: An input light-coupling device comprising a dielectric layer containing a pattern of dielectric contrast distributed in at least two dimensions. The pattern of dielectric contrast, which may or may not be periodic, is designed to facilitate coupling to the dielectric layer of electromagnetic radiation. The electromagnetic radiation may be propagating within a surrounding medium of lower dielectric constant than that of said dielectric layer, input at directions including normal incidence from which light cannot typically couple to the dielectric layer without the presence of the pattern of dielectric contrast. The input light may constitute an optical signal propagating in an optical fiber or in free space. Light that is in-coupled may be directed in as many directions as dictated by the symmetry of the pattern of dielectric contrast. The dielectric layer may contain output waveguides surrounding the input coupling structure.
    Type: Grant
    Filed: April 30, 2001
    Date of Patent: June 3, 2003
    Assignee: Massachusetts Institute of Technology
    Inventors: Alexei A. Erchak, Shanhui Fan, Erich P. Ippen, John D. Joannopoulos, Leslie A. Kolodziejski, Gale S. Petrich, Daniel J. Ripin
  • OPTICAL ISOLATION CREATED BY INDIRECT INTERBAND PHOTONIC TRANSITIONS
    Publication number: 20110002573
    Abstract: The refractive index of the at least one photonic structure having two separate photonic bands is modulated, so that light supplied to the at least one photonic structure and initially in one of the two photonic bands of the traveling along a forward direction in the at least one photonic structure is converted to light in a second one of the photonic bands, and light in the one photonic band traveling along a backward direction opposite to the forward direction in the at least one photonic structure is not converted and remains in the one photonic band, achieving non-reciprocity. An interferometer comprises a first and a second photonic structure coupled at two coupler regions. The first photonic structure has two separate photonic bands.
    Type: Application
    Filed: July 1, 2009
    Publication date: January 6, 2011
    Applicant: The Board of Trustees of the Leland Stanford Junior University
    Inventors: Zongfu Yu, Shanhui Fan
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