Distributed strain and temperature sensing in plastic optical fiber using Rayleigh scatter

Abstract

In recent years we have demonstrated the ability to analyze Rayleigh scatter in single- and multi-mode fused silica fibers to deduce strain and temperature shifts, yielding sensitivity and resolution similar to that obtained using Fiber Bragg Gratings. This technique employs scanning laser interferometry to obtain high spatial resolution Rayleigh scatter spectral information. One of the promising aspects of using Rayleigh scatter for distributed sensing is that the technique should work for any fiber that exhibits discernable Rayleigh scatter. We now demonstrate that distributed sensing with mm-range spatial resolution in off-the-shelf plastic multi-mode optical fiber is feasible. We report temperature and strain sensitivity, and comment on measurement range and hysteresis level. Distributed Rayleigh scatter sensing in plastic optical fiber may offer a valuable alternative to sensing in fused silica fibers because of plastic's low cost and differing mechanical and chemical properties.