Optical fibre sensors and networks for environmental monitoring

Describes the author's work on the development of fibre sensors and networks for monitoring trace gases such as methane, acetylene, carbon dioxide, carbon monoxide, hydrogen sulphide and for detection of spills of gasoline, diesel and organic solvents, all of which are important in environmental and safety management. As an example, a 45-point fibre optic sensor network has been installed on a landfill site to assess the distribution of methane generation across the site. System operation is based on near-IR absorption and is currently being extended to monitor other gases such as carbon dioxide and hydrogen sulphide. Concurrently, research is being conducted on fibre lasers for the realisation of multi-point, multi-gas monitoring systems. Based on other principles (periodic micro-bending loss effects), detection of hydrocarbon fuel spills has been demonstrated at multiple locations along the length of a specially designed fibre optic cable using standard optical time domain reflectometry (OTDR) measurements