Patents by Inventor Howard P. Girdlestone

Howard P. Girdlestone 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).

  • Optical waveguides and their manufacture
    Patent number: 4974933
    Abstract: Optical fibre contains a colloidal semiconductor dispersed in the core or the cladding or both. The fibre may have active regions in which the semiconductor is dispersed and passive regions in which the semiconductor is dissolved. This is obtained by drawing a preform to get fibre in which the semiconductor is dispersed and selected portions (or else the whole fibre) are treated to precipitate the semiconductor in colloidal form.
    Type: Grant
    Filed: May 22, 1987
    Date of Patent: December 4, 1990
    Assignee: British Telecommunications plc
    Inventors: Benjamin J. Ainslie, Howard P. Girdlestone