Patents Represented by Attorney, Agent or Law Firm Simon Mark Kahn
  • Patent number: 6442320
    Abstract: The present invention relates in one aspect, to a refractive index profile designed to support higher order spatial modes, and in particular the LP02 spatial mode in an optical waveguide. The waveguide exhibits negative dispersion and negative dispersion slope and negative third order dispersion over the operating wavelength. In one embodiment, the profile is designed with a reduced refractive index depression in the center core region, and is intended to enhance the properties of the dispersion compensating waveguide. In addition, the refractive index profile of the present invention supports the LP02 mode. A limited mode dispersion compensating optical waveguide according to the present invention includes a center core portion having a center core refractive index. The waveguide also includes an outer core portion surrounding the center core portion and having an outer core refractive index that is greater than the center core refractive index.
    Type: Grant
    Filed: April 14, 2000
    Date of Patent: August 27, 2002
    Assignee: LaserComm Inc.
    Inventors: Yochay Danziger, Michael Rosenblit
  • Patent number: 6434311
    Abstract: An optical waveguide supporting a plurality of modes including an annulus which attenuates a desired mode to a lesser degree than any other mode in the plurality of modes. In one embodiment, the annulus is disposed in the core of the waveguide. In another embodiment, the annulus is concentric about the core. In another embodiment, the annulus has a predetermined width and radius. In yet another embodiment the optical waveguide includes an annulus that is disposed at a radial position corresponding to a region in the core in which the desired mode has substantially no energy. In yet another embodiment the desired mode includes the LP02 mode. In another embodiment, the annulus includes a scattering material. In still another embodiment, the annulus includes a conductive dopant material. Another embodiment includes a sharp change of refractive index within the core. Still other embodiments include disposing a region of increased refractive index in the core of the waveguide to attenuate undesired modes.
    Type: Grant
    Filed: January 12, 2000
    Date of Patent: August 13, 2002
    Assignee: LaserComm Inc.
    Inventors: Yochay Danziger, Eran Herman, Uri Levy, Michael Rosenblit
  • Patent number: 6418256
    Abstract: The invention relates to method and apparatus for transmitting an optical signal having optical energy substantially in a high order spatial mode. The optical waveguide, in one embodiment, includes a few mode fiber designed to have specific transmission characteristics for supporting the single high order spatial mode, and the few mode fiber transmits the single high order spatial mode. The optical waveguide, in one embodiment, has a dispersion and a dispersion slope for a given transmission bandwidth. Another aspect of the invention includes a method for transmitting an optical signal having optical energy substantially in a single high order spatial mode. The method includes the steps of providing a few mode fiber, which supports optical energy in the single high order spatial mode. In one embodiment, the single high order spatial mode is the LP02 spatial mode In another embodiment, the few mode fiber supports an optical signal having optical energy having less than twenty spatial modes.
    Type: Grant
    Filed: February 22, 2000
    Date of Patent: July 9, 2002
    Assignee: LaserComm, Inc.
    Inventors: Yochay Danziger, Eran Herman, David Menashe, Michael Rosenblit
  • Patent number: 6404951
    Abstract: A transverse spatial mode transformer for transforming an optical signal between different spatial modes is described. The transformer is based on a spatially selective change of the phase of the optical signal wavefront relative to the initial wavefront. As the phase-adjusted optical signal propagates, the transverse intensity distribution changes to correspond to the new spatial mode. The transformer can be used to change the lower order spatial mode of an optical signal to a higher order spatial mode appropriate for a dispersion compensated fiber optic communication system. The transformer can also be used to change a higher order spatial mode to a lower order spatial mode.
    Type: Grant
    Filed: February 12, 1999
    Date of Patent: June 11, 2002
    Assignee: LaserComm Inc.
    Inventor: Yochay Danziger
  • Patent number: 6377726
    Abstract: The invention relates to apparatus and methods for transforming a spatial mode of an optical signal. The apparatus includes an optical phase element for imparting a predetermined spatially selective phase delay to the optical signal, and a mask in optical communication with the optical phase element. The mask, in one embodiment, includes an optically attenuating region disposed in a predetermined spatial pattern. In one aspect of the invention, the optical signal is transformed from a first spatial mode to a second spatial mode. In another aspect of the invention, the mask includes an absorbing material arranged in a predetermined spatial pattern. In yet another aspect of the invention, the mask includes a scattering material arranged in a predetermined spatial pattern. The invention also relates to a method for transforming a spatial mode of an optical signal. The method includes the step of receiving the optical signal having a first spatial mode with an intensity distribution and a phase.
    Type: Grant
    Filed: February 29, 2000
    Date of Patent: April 23, 2002
    Assignee: LaserComm Inc.
    Inventors: Yochay Danziger, Ofer Braude, Eran Herman
  • Patent number: 6339665
    Abstract: A dispersion compensation device uses at least two chromatic dispersion compensation fibers to compensate for chromatic dispersion present in an optical communication system. Two dispersion orders can be corrected using appropriate lengths of two serially coupled compensation fibers having different dispersion characteristics. The device can compensate for N additional orders of dispersion by using N additional compensation fibers with unique dispersion characteristics. The device can be coupled directly to a transmission fiber.
    Type: Grant
    Filed: February 12, 1999
    Date of Patent: January 15, 2002
    Assignee: LaserComm Inc.
    Inventor: Yochay Danziger
  • Patent number: 6327403
    Abstract: An optical waveguide supporting a plurality of modes including an absorbing annulus which attenuates a desired mode to a lesser degree than any other mode in the plurality of modes. In one embodiment, the absorbing annulus is disposed in the core of the waveguide. In another embodiment, the annulus is concentric about the core. In another embodiment, the annulus has a predetermined width and radius. In yet another embodiment the desired mode includes the LP02 mode.
    Type: Grant
    Filed: December 17, 1999
    Date of Patent: December 4, 2001
    Assignee: LaserComm Inc.
    Inventors: Yochay Danziger, Eran Herman, Uri Levy, Michael Rosenblit