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:
Oct. 25, 1994
Filed:
Nov. 06, 1992
Jeffrey P Andrews, Abingdon, MD (US);
Martin Marietta Corporation, Bethesda, MD (US);
Abstract
A device and method are described for measuring changes association with a gap between a lead-in optical fiber and a lead-out optical fiber. A hybrid fiber optic sensor is created by inserting the lead-in and lead-out optical fibers into a small tube such that a gap is provided between the fibers. Laser pulses incident on the gap create two interfacial reflections that interfere with one another, thus providing a method of measuring changes in gap length in the same was as a typical Fabry-Perot type interferometer. Moreover, a reflection from the far end of the lead-out fiber gives gap information in the same way as typical intensity-based sensor. Together the two measurements overcome the limitations that occur when each technique is used separately, and are made possible by means of the above hybrid fiber optic sensor which contains both a Fabry-Perot interferometer portion and an intensity-based sensor portion.