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:
Apr. 17, 1990
Filed:
Aug. 01, 1988
Marek T Wlodarczyk, Birmingham, MI (US);
Mark K Krage, Royal Oak, MI (US);
Deborah J Vickers, Malibu, CA (US);
General Motors Corporation, Detroit, MI (US);
Abstract
A microbend fiber optic pressure sensor includes a short length of sensing fiber comprising a fiber of a transparent dielectric material surrounded by a layer of aluminum or similar metal for which the real part of the complex permittivity is negative over a range of electromagnetic radiation wavelengths. The layer of aluminum is hermetically sealed to the transparent material. The sensing fiber receives light in the range of wavelengths and is subjected to microbends on the dielectric/aluminum boundary by pressure responsive mechanical apparatus for a much greater microbend light loss and therefore greater sensitivity than is obtained with similar sensors using an all glass core/cladding boundary. The sensing fiber may be an aluminum coated single mode fiber with a very small core and a large cladding layer in which the cladding modes are used and the core modes ignored or it may comprise a single glass fiber coated with aluminum. The sensing fiber is used only in the sensing region, with light coupled to one end from a light source and from the other end to a light detector through lower loss multimode optic fibers.