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:
Jul. 22, 2008
Filed:
Aug. 02, 2006
Cary R. Murphy, Hickory, NC (US);
Mark K. Bridges, Hickory, NC (US);
Joseph Giovanni, Hickory, NC (US);
David E. Vokey, Sidney, CA;
Cary R. Murphy, Hickory, NC (US);
Mark K. Bridges, Hickory, NC (US);
Joseph Giovanni, Hickory, NC (US);
David E. Vokey, Sidney, CA;
Network Integrity Systems Inc., Conover, NC (US);
Abstract
Intrusion detection for a multimode fiber optic cable uses a light signal launched into the fiber through the low ratio leg of a tap coupler to establish a narrow spectral width, under-filled non-uniform mode field power distribution in the cable. A small portion of the higher order signal modes at the remote end is monitored for transient changes in the mode field power distribution which are characteristic of fiber intrusion to activate an alarm. The active signal of a multimode optical fiber is monitored for both signal degradation and transient power disturbance patterns that could indicate fiber damage or physical intrusion. A translator can be provided in an existing optical fiber system in which the data signals are translated in wavelength and/or launch conditions to optimize the monitoring signals in an otherwise non-optimized system.