Patents Examined by Jessica L. Rooff
  • Patent number: 4709145
    Abstract: Apparatus and method for compensating a photo sensor for fiber optic cable lead/connector losses and optical source power fluctuations includes a specially selected broadband optical source used in conjunction with a photoelastic fiber optic transducer that uses a polarizer and an analyzer that only polarize a portion of the broadband signal. The portion of the signal that is not polarized is simply transmitted through the photoelastic element and emerges with no modulation. The portion of the signal that is polarized is modulated according to the stress on the photoelastic element. After transmitting the output light beam through a single fiber optic cable, the beam is separated into two parts. The first part is filtered so as to transmit only that portion of the broadband signal that is not affected by the polarizer and analyzer and hence is not modulated. The filtered first part is converted to an electrical signal by a photo detector.
    Type: Grant
    Filed: August 20, 1986
    Date of Patent: November 24, 1987
    Assignee: Simmonds Precision Products, Inc.
    Inventor: William B. Spillman, Jr.