The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 24, 1993
Filed:
Dec. 21, 1989
Hiroshi Kajioka, Hitachi, JP;
Hitachi Cable Limited, Tokyo, JP;
Abstract
The fiber-optic rotation sensor comprises a sensing loop using an optical fiber which essentially performs a single polarization when bent, both end portions of the sensing loop being disposed with the principal axes of polarization thereof orthogonal to each other and the end portions being joined by an evanescent wave coupling to form a ring interferometer, a device for introducing to an input end of the interferometer a linearly polarized light at a bearing of 45.degree. relative to the principal axis of polarization of the interferometer, and a retardation measuring system provided at an output end of the interferometer for picking up an electrical output proportional to a rotational angular velocity applied to the interferometer. When the linearly-polarized light is introduced to the input end of the coupling portion of the ring interferometer at a bearing of 45.degree. with respect to the principal axis of polarization of the interferometer, the light is branched into two polarized light beams running through the sensing loop, one clockwise and the other counterclockwise. The polarized light beams are recombined with each other to be input to the retardation measuring system from which an electrical output proportional to the rotational angular velocity applied to the interferometer is picked up.