Nonreciprocal Polarization Rotators Patents (Class 333/24.3)
  • Patent number: 7501909
    Abstract: A polarization modulator device for modulating a polarization of an electromagnetic wave includes a corrugated metallic waveguide having an interior cylindrical opening defined therein and situated along a longitudinal axis of the waveguide. The corrugated metallic waveguide also has a first waveguide section and a second waveguide section. The waveguide sections are separated by a dielectric break. A central structure is situated along the longitudinal axis of the waveguide. The central structure is supported substantially in the center of the interior cylindrical opening of the waveguide. The cylinder is substantially situated within the dielectric break of the waveguide. A magnetic field source is configured to permit a controllable magnetic field in the cylinder, wherein the magnetic field modulates a polarization of the electromagnetic wave by an angle related to the strength of the magnetic field. A polarimeter using the polarization modulator is also described.
    Type: Grant
    Filed: June 9, 2006
    Date of Patent: March 10, 2009
    Assignee: California Institute of Technology
    Inventors: Brian Gregory Keating, Andrew E. Lange
  • Patent number: 7206116
    Abstract: A Faraday rotator for a Faraday isolator with an input polarizer, with an output polarizer, with a roller-shaped optical crystal that is arranged therebetween and that is arranged symmetrical to its axis of symmetry, with a right hollow cylinder that surrounds this and has a hollow space made of a permanent magnetic material, which cylinder is axially magnetized and the magnetic field of which extends in the hollow space approximately parallel to the axis of symmetry that runs in only one direction from the north pole to the south pole, and with terminal magnets attached to each of the two end faces in the plane perpendicular to the y- and z-directions of the axis of symmetry, each of which is embodied as a hollow right cylinder and has a through-aperture in the extension of the axis of symmetry, is characterized in that each terminal magnet is largely radially magnetized with regard to the axis of symmetry at least by region, in that the one of the two terminal magnets is magnetized radially from interior to
    Type: Grant
    Filed: April 21, 2004
    Date of Patent: April 17, 2007
    Assignee: Linos Photonics GmbH & Co. KG
    Inventors: Thomas Fehn, Sven Poggel, Stefan Balle
  • Publication number: 20040222869
    Abstract: Methods and devices for accelerating or delaying an electromagnetic signal. A rectangular waveguide phase shifter has a ferrite filled center section with a pair of magnetic bias lines placed on opposing sides of the waveguide, each bias line being adjacent to one of the two opposing sides. Each magnetic bias line creates a magnetic field in the ferrite filled center section. The resulting magnetic field in half of the center section has the same magnitude but is oppositely directed to the magnetic field in the other half of the center section. This ideally results in a zero magnetic field at the very center of the ferrite filled center section. A microwave signal propagates through the waveguide phase shifter in a direction perpendicular to the magnetic field lines. The amount of phase shift provided depends on the magnitude of the magnetic fields. These magnetic fields are controllable by adjusting the current passing through the bias lines.
    Type: Application
    Filed: May 5, 2003
    Publication date: November 11, 2004
    Inventors: Joey Bray, Langis Roy
  • Publication number: 20010052828
    Abstract: A material for a bismuth substituted garnet thick film comprising Gd, Yb, Bi, Fe and Al as the main ingredient grown by a liquid phase growing method on a garnet substrate in which the composition of the garnet thickness is represented by the general formula:
    Type: Application
    Filed: June 5, 2001
    Publication date: December 20, 2001
    Applicant: TOKIN CORPORATION
    Inventors: Tadakuni Sato, Kazumitsu Endo