Fiber-Optic Technology for Fully-Distributed Physical, Chemical, and Biological Sensing

Virginia Polytechnic Institute And State University, Blacksburg VA

Investigators

Abstract

The objective of the project is to develop an optical fiber sensor technology that will enable fully-distributed simultaneous measurement of physical, chemical, and biological parameters in a single fiber. This approach is based on a novel traveling long period grating (LPG), generated either acoustically or optically in a single-mode fiber. The spatially-localized traveling grating couples the guided optical mode in the fiber core to cladding modes, which then interact with functional coatings on the surface of the fiber to cause the transmitted optical spectrum to shift. Unlike traditional LPGs, which are limited to single-point measurement, the traveling LPG enables fully-distributed sensing. By partitioning of different surface coatings, each of which can have selective response to different parameters, a variety of physical, chemical, and biological parameters can be measured with a single fiber. This research will culminate in a full system demonstration for distributed measurement of various physical, chemical, and biological parameters with one fiber. Future applications of this work include pollution detection in rivers and lakes, chemical-bio terrorism agent detection for a variety of public venues, hydrogen detection in future hydrogen energy systems, and leak detection in long pipelines for various gaseous or liquid chemical delivery.