Distributed Fiber Optic In-Line Intrusion Sensor System

Author

Fang, Nian ; Jia, Dongjian ; Wang, Lutang ; Huang, Zhaoming

Author_Institution

Key Lab. of Specialty Fiber Opt. & Opt. Access Networks, Shanghai Univ., Shanghai

fYear

2008

fDate

10-12 Sept. 2008

Firstpage

608

Lastpage

611

Abstract

A novel fiber optic in-line distributed sensor system for location of an intrusion is proposed. A 3 dB coupler and a Faraday rotation mirror (FRM) are employed to form an interferometer. There are two light paths that have the same optical length but travel different sequence paths in the interferometer. These two paths pass through the intrusion point at different time, so the phase difference is existent. After interference, a fast Fourier transform (FFT) is applied on the output signal to obtain the phase angle in the double intrusion frequency. And then the position of the intrusion point can be determined. Simulation results show that this fiber optic in-line distributed sensor system can locate the intrusion point at a distance of 40 km, with the deviation no more than 130 m, and the relative error is 0.32%.

Keywords

Faraday effect; distributed sensors; fast Fourier transforms; fibre optic sensors; integrated optics; light interferometers; mirrors; optical fibre couplers; safety systems; Faraday rotation mirror; coupler; distributed fiber optic in-line intrusion sensor system; fast Fourier transform; interferometer; optical length; phase angle; phase difference; Fast Fourier transforms; Mirrors; Optical fiber polarization; Optical fiber sensors; Optical fibers; Optical interferometry; Optical sensors; Optical signal processing; Sagnac interferometers; Sensor systems; Fast Fourier transform (FFT); in-line distributed fiber optical sensors; intrusion detection; phase angle;

fLanguage

English

Publisher

ieee

Conference_Titel

Microwave Conference, 2008 China-Japan Joint

Conference_Location

Shanghai

Print_ISBN

978-1-4244-3821-1

Type

conf

DOI

10.1109/CJMW.2008.4772505

Filename

4772505