Patents by Inventor Walter Johnstone

Walter Johnstone 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: 6466729
    Abstract: Controllable fiber optic attenuators and attenuation systems are disclosed for controllably extracting optical energy from a fiber optic, and therefore attenuating the optical signal being transmitted through the fiber optic. A portion of the fiber optic is etched or tapered, thereby providing a side surface through which optical energy can be extracted. The portion of the fiber is suspended between two support points, and a controllable material is formed over the surface for controllably extracting optical energy according to a changeable stimulus applied thereto, which affects the refractive index thereof. In one embodiment, the changeable stimulus is temperature, and a controllable heating/cooling source can be provided in the attenuator for control of the attenuation. The limited amount of thermal contact between the suspended portion of the fiber optic and the controllable material to surrounding structures offers a more predictable response, and improved response time.
    Type: Grant
    Filed: March 30, 2000
    Date of Patent: October 15, 2002
    Assignee: Molecular Optoelectronics Corporation
    Inventors: Gregory A. Wagoner, Kevin J. McCallion, Walter Johnstone, Kwok Pong Chan, David G. Gascoyne