Patents by Inventor Paul W. France

Paul W. France 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).

  • Method of making halide fibers including casting under a reduced pressure
    Patent number: 5401289
    Abstract: Halide glass articles, e.g. rods, tubes and preforms for making fluoride glass fibres, are prepared by melting and/or casting the articles under a low pressure, e.g. 0.01 to 500 mbars and, during the low pressure regime, a gas flow rate of between 0.01 to 100 liters/min (measured at NTP) is maintained. It has been found that subjecting the melts to a low pressure reduces the attenuation of the fibre which eventually results from the melts.
    Type: Grant
    Filed: March 7, 1994
    Date of Patent: March 28, 1995
    Assignee: British Telecommunications public limited company
    Inventors: Paul W. France, Steven F. Carter, John R. Williams
  • Method for the preparation of halide glass articles
    Patent number: 5334232
    Abstract: Halide glass articles, e.g. rods, tubes and preforms for making fluoride glass fibres, are prepared by melting and/or casting the articles under a low pressure, e.g. 0.01 to 500 mbars and, during the low pressure regime, a gas flow rate of between 0.01 to 100 liters/min (measured at NTP) is maintained. It has been found that subjecting the melts to a low pressure reduces the attenuation of the fibre which eventually results from the melts.
    Type: Grant
    Filed: March 4, 1993
    Date of Patent: August 2, 1994
    Assignee: British Telecommunications Public Limited Company
    Inventors: Paul W. France, Steven F. Carter, John R. Williams
  • Surface treatments for optical fibre preforms
    Patent number: 4973345
    Abstract: Halide fibres are protected by coatings up to 2 .mu.m thick of chalcogenide glasses, eg glasses based on compounds of S, Se or Te with Ge or As. The coatings are deposited on the fibre preform by ion deposition sputtering. Preferably the preform is ethced by directing a stream of inert ions at it. Most suitably the etching immediately precedes the coating.
    Type: Grant
    Filed: October 13, 1987
    Date of Patent: November 27, 1990
    Assignee: British Telecommunications Public Limited Company
    Inventor: Paul W. France
  • Surface treatments for optical fibre preforms
    Patent number: 4863237
    Abstract: Halide fibers are protected by coatings up to 2.mu.m thick of chalcogenide glasses, e.g. glasses based on compounds of S, Se or Te with Ge or As. The coatings are deposited on the fiber preform by ion deposition sputtering. Preferably the preform is etched by directing a stream of inert ions at it. Most suitably the etching immediately precedes the coating.
    Type: Grant
    Filed: January 4, 1988
    Date of Patent: September 5, 1989
    Assignee: British Telecommunications Public Limited Company
    Inventor: Paul W. France
  • Cables comprising optical fibres of halide glass
    Patent number: 4856868
    Abstract: An optical fibre cable for radiation monitoring, e.g. remote spectroscopy, has the fibres immersed in a water miscible liquid such as ethylene glycol or isopropanol. It has been found that water miscible liquids protect even fluoride fibre against attack by water, e.g. water which diffuses into the bore of a cable during its useful life.
    Type: Grant
    Filed: February 19, 1988
    Date of Patent: August 15, 1989
    Assignee: British Telecommunications public limited company
    Inventors: Paul W. France, Steven F. Carter, Martin W. Moore
  • Method of preparing a halide optical fibre
    Patent number: 4848997
    Abstract: A process for treating a halide, e.g. fluoride, glass composition, characterized by contacting a melt of the composition (3) with dry oxygen (6). Oxygen, simply on contact with a fluoride glass melt, converts transition metals, e.g. from Fe(II) to Fe(III), from one stable state to another and thereby reduces loss at transmission wavelengths in optical fibre, e.g. the loss at 2.6 .mu.m attributabel to Fe(II).
    Type: Grant
    Filed: April 5, 1988
    Date of Patent: July 18, 1989
    Assignee: British Telecommuncations plc
    Inventors: Paul W. France, John R. Williams, Steven F. Carter
  • Halide fibre with high numerical aperture
    Patent number: 4836643
    Abstract: A high numerical aperture optical fibre, e.g. for use in remote spectroscopy, has a cladding of a halide glass which contains Hf and a core of a halide glass which contains Pb. Preferably both glasses contain ZrF.sub.4, BaF.sub.2, LaF.sub.3, AlF.sub.3 and NaF. In addition the cladding contains HfF.sub.4 but no PbF.sub.2 and the core contains PbF.sub.2 but no HfF.sub.4.
    Type: Grant
    Filed: February 2, 1988
    Date of Patent: June 6, 1989
    Assignee: British Telecommunications public limited company
    Inventors: Paul W. France, John R. Williams
  • Treating glass compositions
    Patent number: 4741752
    Abstract: A process for treating a halide, e.g. fluoride, glass composition, characterized by contacting a melt of the composition with dry oxygen. Oxygen, simply on contact with a fluoride glass melt, converts transition metals, e.g. from Fe(II) to Fe(III), from one stable state to another and thereby reduces loss at transmission wavelengths in optical fiber, e.g. the loss at 2.7 .mu.m attributable to Fe(II).
    Type: Grant
    Filed: July 18, 1985
    Date of Patent: May 3, 1988
    Assignee: British Telecommunications plc
    Inventors: Paul W. France, John R. Williams, Steven F. Carter
  • Method for drying oxide glasses
    Patent number: 4539033
    Abstract: An oxide glass is dried by passing through a melt of the glass fluorine or another perhalogenated compound including fluorine atoms. For example, C.sub.3 F.sub.8 (e.g. after pre-cracking) can be used to reduce the OH content of a borosilicate glass, and the loss of an optical fibre drawn from such a glass, to low levels.
    Type: Grant
    Filed: September 8, 1983
    Date of Patent: September 3, 1985
    Assignee: British Telecommunications
    Inventors: Keith J. Beales, Steve F. Carter, Sally Partington, Paul W. France
  • Optical fibres and coatings therefor
    Patent number: 4410567
    Abstract: In order to provide improved resistance to attack by atmospheric water etc. a clad glass optical fibre has a plastic coating which is in turn coated with a metal coating. The metal coating may in turn be coated with a second plastic coating. The metal coating is formed by drawing the plastic coated fibre through a globule of molten metal, the surface of which is exposed to an oxygen rich atmosphere.
    Type: Grant
    Filed: April 15, 1982
    Date of Patent: October 18, 1983
    Assignee: Post Office
    Inventors: Paul W. France, George R. Newns
  • Testing glass fibres
    Patent number: 4346601
    Abstract: A method of proof testing an optical glass fibre by pulling it around a free roller whose radius is sufficiently small to impart the strain necessary to detect fibres whose surface or near surface flaws weaken the fibre below a required strength. Proof testers are disclosed incorporating, single rollers, a set of three parallel rollers and a jig holding four sets of three rollers. Proof testers incorporating the extra rollers whose axes are at different angles are shown to more thoroughly explore the surface of the fibre for cracks.
    Type: Grant
    Filed: August 18, 1980
    Date of Patent: August 31, 1982
    Assignee: The Post Office
    Inventor: Paul W. France