BOTDR for Detection of Chemical and Liquid Content

A new water sensor using Brillouin Optical Time Domain Reflectometry (BOTDR) is presented in its early developmental stages. The sensor takes advantage of the growing fiber optic technology that particularly uses optical fibers as strain sensors on civil infrastructures. When these strain sensors are combined with polymers that react to target chemicals by swelling, the swelling forces transfer strain directly to the fiber for detection. By superimposing these two technologies, a sensor that is capable of detecting target chemicals continuously along a prescribed line from remote locations is possible. This paper is an overview on the theory of the BOTDR sensor technology along with results from a small-scale pilot test using a water sensitive polymer. The swelling potential of the polymer is proven to be strong enough to impose strains that are capable of being detected by optical equipment. Other properties of this hybrid sensor currently being investigated are selectivity, stability, rapid response, low detection limit, reversibility and longevity.