Patents by Inventor Christopher Chew

Christopher Chew 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).

  • Polarization insensitive wavelength multiplexing 2.times.2 fibre couplers
    Patent number: 5408555
    Abstract: In the manufacture of a wavelength multiplexing 2.times.2 tapered fused fiber coupler by progressive stretching, the birefringence of the coupler resulting from the progressive stretching is subsequently nulled-out by elastic twisting of the coupler. The progressive stretching is performed, under temperature conditions providing a profile in the coupling region of the coupler having the property that the coupling strength for one of the principal polarization planes of the coupler remains substantially constant during said elastic twisting.
    Type: Grant
    Filed: April 5, 1994
    Date of Patent: April 18, 1995
    Assignee: Northern Telecom Limited
    Inventors: Alan Fielding, Christopher Chew, Vernon Baker, Sandra Davis