Patents by Inventor Peter K. Cheo

Peter K. Cheo 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).

  • Patent number: 7107795
    Abstract: A method for forming a multicore fiber laser array includes inserting a plurality of rare-earth doped rods into a corresponding plurality of hollow capillaries, and arranging the resulting plurality of filled capillaries into a preform pattern. The plurality of filled capillaries are collapsed into an initial preform structure, wherein a portion of the material of the capillaries forms an initial inner cladding. The initial preform structure is inserted into a cylinder, wherein the cylinder and the initial preform structure are fused so as to form a final preform structure with a final inner cladding having an increased thickness with respect to the initial inner cladding. At least one flat surface is formed along the length of the final preform structure, and a fiber is simultaneously drawn from the final preform structure and a layer of outer cladding material.
    Type: Grant
    Filed: February 5, 2004
    Date of Patent: September 19, 2006
    Inventor: Peter K. Cheo
  • Patent number: 6801549
    Abstract: A single core 35, 50 or a plurality of cores arranged in rings 21, 28, 29 around a central core 20, 27, or in an array 42, are provided with either or both of (a) a modal discrimination characteristic, including gain, index of refraction and cross sectional area, which is greatest in the center of the core or the array, and lowers outwardly therefrom, and (b) an oblong cross section, thereby to provide either or both of (c) a bright laser beam of the fundamental in-phase supermode, and/or (d) a linearly polarized output beam.
    Type: Grant
    Filed: August 25, 2000
    Date of Patent: October 5, 2004
    Assignee: PC Photonics Corporation
    Inventors: Peter K. Cheo, George G. King
  • Patent number: 6766075
    Abstract: Efficient delivery of large amounts of pump laser power distributed along the cladding (11, 54) of a single core (6) or multiple core (7, 51) laser fiber, without degrading the fiber integrity or compromising the fiber's waveguiding property, is accomplished by injecting the power into the cladding via delivery fibers (18, 30, 42, 62) permanently affixed to a peripheral wall (20, 56) at an angle that satisfies the condition for total internal reflection of the pump radiation so that it is confined within the inner cladding of the laser fiber. In one embodiment, the laser fiber (51) is wrapped around a drum (53). Each delivery fiber has a numerical aperture (NA) less than half the NA of the laser fiber, and a core 21 having a refractive index substantially the same as that of the inner cladding (11) of the laser fiber.
    Type: Grant
    Filed: February 13, 2002
    Date of Patent: July 20, 2004
    Assignee: PC Photonics Corporation
    Inventors: George G. King, Peter K. Cheo
  • Patent number: 6031850
    Abstract: A fiber laser 10 with square inner cladding 12, 29 may have a single core 11 codoped either with Ytterbium or Erbium or with Thulium and Holmium at a ratio of at least 10:1 operating in a single mode to provide eye-safe radiation with wavelengths above 1.5 micron. The single core laser has a pump clad cross sectional area about 2(10).sup.3 greater than the cross sectional area of the core. A multi-core laser has a plurality of single mode cores 28 doped with any rare earth ions, the cores equally spaced by at least two core diameters in an isometric array, in a cavity having a finesse of greater than ten, to produce a single, very bright phase-locked beam in the fundamental supermode. A method starts with hexagonal cladded-core rods 35, 36 in an isometric array, which are then fused and drawn down.
    Type: Grant
    Filed: March 9, 1999
    Date of Patent: February 29, 2000
    Assignee: PC Photonics Corporation
    Inventor: Peter K. Cheo
  • Patent number: 4973140
    Abstract: A novel single sideband electro-optic modulator is characterized by a reentrant waveguide structure. The reentrant waveguide structure allows for a factor of four enhancement of conversion efficiency and a factor of five reduction in phase velocity mismatch between the optical wave and modulating microwave due to microwave dispersion in wideband (2 GHz) operation.
    Type: Grant
    Filed: January 25, 1989
    Date of Patent: November 27, 1990
    Assignee: United Technologies Corporation
    Inventors: Peter K. Cheo, Robert A. Rubino, Meyer Gilden
  • Patent number: 4897622
    Abstract: A novel single sideband electro-optic modulator includes a planar waveguide structure allowing only circularly polarized optical and microwaves to propagate therein with equal phase velocities comprises a strip loaded GaAlAs/GaAs/GaAlAs structure with appropriate microstrip electrodes. The present modulator is readily fabricated using established microelectronic fabrication techniques and a modified MOCVD epitaxial growth process.
    Type: Grant
    Filed: December 22, 1988
    Date of Patent: January 30, 1990
    Assignee: United Technologies Corporation
    Inventors: Peter K. Cheo, Gerald Meltz
  • Patent number: 4707060
    Abstract: A microwave infrared modulator having a novel three dimensional structure is presented. The modulator includes a waveguide and metal base with a dielectric wafer buried therebetween. The buried wafer allows for conventional microstrip structures to be employed with larger microstrip electrode dimensions than would otherwise be possible.
    Type: Grant
    Filed: April 4, 1985
    Date of Patent: November 17, 1987
    Assignee: United Technologies Corporation
    Inventors: Peter K. Cheo, Meyer Gilden
  • Patent number: 4693549
    Abstract: An electro-optic infrared modulator is provided that it contains an optically buffered waveguide. The buffer comprises a dielectric layer on the top and bottom surface of the waveguide which provides enhanced optical isolation and enables improved synchronization between the microwave and optical waves traveling in the waveguide.
    Type: Grant
    Filed: April 4, 1985
    Date of Patent: September 15, 1987
    Assignee: United Technologies Corporation
    Inventor: Peter K. Cheo
  • Patent number: 4685988
    Abstract: A broadband infrared microwave modulator is fabricated with a thin film electro-optic waveguide mounted to a metal base substrate having a dielectric wafer buried therein to allow high power operation of the modulator.
    Type: Grant
    Filed: April 4, 1985
    Date of Patent: August 11, 1987
    Assignee: United Technologies Corporation
    Inventors: Robert A. Wagner, Peter K. Cheo
  • Patent number: 4363966
    Abstract: A technique which detects for the presence of particles or voids in material is disclosed herein. This technique utilizes an overall optics arrangement for producing a beam of radiation and for directing the latter into and through the material such that any void or foreign particle which is present causes the radiation impinging thereon to form an overall scattering pattern distinctly characteristic of whether the impinged void or foreign particle is generally spherical or non-spherical in shape. The technique disclosed herein also provides an arrangement for detecting scattered radiation, if any, and distinguishing between spherical and non-spherical foreign particles and, in a preferred embodiment, whether the impinged void/foreign particle is relatively large or small, relative to wavelength of said beam.
    Type: Grant
    Filed: September 22, 1980
    Date of Patent: December 14, 1982
    Assignee: Electric Power Research Institute, Inc.
    Inventor: Peter K. Cheo
  • Patent number: 4208126
    Abstract: A system for detecting foreign particles or voids in the outer insulation jacket of an electrical cable is disclosed herein and utilizes a laser beam of electromagnetic radiation at a given wavelength, preferably within the far-infrared band. This laser is directed into the insulation jacket's cylindrical surface, which must be index-matched with a proper medium such that any portion thereof passing through the insulation jacket unobstructed by voids or foreign matter does so along a predictable primary beam path, and such that any portion impinging a void or foreign particle is caused to scatter along predictable scattering paths including paths which are different than the primary beam path. In this way, at least one detector can be properly aligned in at least one of these different scattering paths for detecting a portion of the scattered radiation, thereby indicating the presence of a void or foreign particle.
    Type: Grant
    Filed: May 24, 1978
    Date of Patent: June 17, 1980
    Assignee: Electric Power Research Institute, Inc.
    Inventors: Peter K. Cheo, Arnold J. Cantor
  • Patent number: 4208091
    Abstract: A broadband microwave waveguide modulator uses microwave signal frequencies to provide phase modulation of an infrared laser propagating in a guided mode through a common electrooptic interaction region in the form of a microstrip transmission line, provided by electroplating microwave electrodes on each of two mutually opposed major surfaces of a monolithic, thin-film optical waveguide having uniform thickness, to provide a high efficiency conversion of a portion of the laser carrier power into optical sideband signals.
    Type: Grant
    Filed: November 13, 1978
    Date of Patent: June 17, 1980
    Assignee: United Technologies Corporation
    Inventors: Peter K. Cheo, Meyer Gilden
  • Patent number: 4197457
    Abstract: A system for detecting foreign particles or voids in plastic material is disclosed herein and utilizes a far-infrared laser beam of electromagnetic radiation at a given wavelength. This laser beam is directed into the plastic material such that any portion thereof passing through the material unobstructed by voids or foreign matter does so along a predictable primary beam path, and such that any portion impinging a void or foreign particle is caused to scatter along predictable scattering paths including paths which are different than the primary beam path. In this way, at least one detector can be properly aligned in at least one of these different scattering paths for detecting a portion of the scattered radiation, thereby indicating the presence of a void or foreign particle.
    Type: Grant
    Filed: May 24, 1978
    Date of Patent: April 8, 1980
    Assignee: Electric Power Research Institute, Inc.
    Inventor: Peter K. Cheo
  • Patent number: 4169009
    Abstract: A plurality of different monolithic, three-dimensional thin-film infared waveguide structures having high optical power handling capability, low optical propagating loss, long propagation and interaction length and distortion-free characteristics are fabricated through high precision mechanical, chemo-mechanical, and ion-beam thinning of a bulk crystal wafer.
    Type: Grant
    Filed: March 30, 1977
    Date of Patent: September 25, 1979
    Assignee: United Technologies Corporation
    Inventors: Robert A. Wagner, Peter K. Cheo
  • Patent number: 4124270
    Abstract: A plurality of different configuration, monolithic, three-dimensional thin-film infrared waveguide structures having high optical power handling capability, low optical propagating loss, long propagation and interaction length and distortion-free characteristics are disclosed, each having characteristics for use in electrooptic and acousto-optic applications.
    Type: Grant
    Filed: March 30, 1977
    Date of Patent: November 7, 1978
    Assignee: United Technologies Corporation
    Inventor: Peter K. Cheo