Patents by Inventor Richard S. Lowe

Richard S. Lowe 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: 4734117
    Abstract: Optical waveguide having a fused silica core and a fluorine doped fused silica cladding is made by depositing particulate core silica onto a support tube and then drying and densifying the silica. Further particulate cladding silica is deposited and is heated in a fluorine containing gas to effect drying, fluorine diffusion into and sintering the cladding silica. The support tube is etched away and the resulting tubular preform is heated to collapse it into a rod from which waveguide is drawn, the waveguide having a fluorine doped silica cladding.
    Type: Grant
    Filed: March 30, 1987
    Date of Patent: March 29, 1988
    Assignee: Northern Telecom Limited
    Inventors: Peter J. Pilon, Richard S. Lowe
  • Patent number: 4723828
    Abstract: To improve pulse dispersion of a multimode fiber transmission line, it is spliced to a short length of fiber adapted to strongly attenuate mode groups propagating near the core center.
    Type: Grant
    Filed: November 9, 1984
    Date of Patent: February 9, 1988
    Assignee: Northern Telecom Limited
    Inventors: Philip-Michael Garel-Jones, Richard S. Lowe
  • Patent number: 4636071
    Abstract: The fundamental-mode field radius `w` is a key parameter in characterizing optical fibers. `w` is a function of P, .theta. and .lambda. where P is the far-field power passing through a circular aperture subtending a solid angle of 2.theta. at the fiber end face and .lambda. is the center wavelength of transmitted length. `w` is derived by moving a fixed diameter aperture along an axis extending between the test fiber end surface and a photodetector so as effectively to vary .theta.. At each location the power P incident on the photodetector and the corresponding acceptance angle .theta. are measured. A microprocesor is programmed to compute from the range of measured values of .theta. and P, the value of mode field radius for a particular transmission wavelength .lambda..
    Type: Grant
    Filed: November 6, 1985
    Date of Patent: January 13, 1987
    Assignee: Northern Telecom Limited
    Inventors: Richard S. Lowe, Constantine Saravanos
  • Patent number: 4551019
    Abstract: The chromatic dispersion of an optical fiber such as a 10 to 50 km length of single mode fiber is measured by launching into the fiber the outputs of at least three commonly modulated semiconductor lasers having output wavelengths close to a region of minimum chromatic dispersion of the fiber. At a remote end of the fiber the relative phases of the signals from the three lasers are determined and a chromatic dispersion profile of the fiber is derived from the measured relative phases and the output wavelenghts of the lasers by assuming a parabolic relationship between signal propagation times and wavelength. The profile can be determined by defferentiating a parabolic function fitted to the three date points derived using said three lasers or by directly generating a linear relationship between chromatic dispersion and wavelength on the basis of two values of chromatic dispersion derived from these three data points.
    Type: Grant
    Filed: August 8, 1983
    Date of Patent: November 5, 1985
    Assignee: Northern Telecom Limited
    Inventors: Paul J. Vella, Philip M. Garel-Jones, Richard S. Lowe