Fiber optic distributed sensing scheme for monitoring structural strain and deformation

A fiber optic distributed sensing scheme used to monitor structural strain and deformation is presented. In the sensor system, a high-birefringent optical fiber is used as the sensing fiber, and the sensor units along the sensing fiber distribution are arrayed on a measured test structure. The structural deformation can be evaluated by detecting the polarization made coupling effect in each sensor unit along the high-birefringent fiber. Interferometry and optical path scanning are used to determine the location and magnitude of the mode-coupling effects caused by structural strain or deformation. (C) 1997 Society of Photo-Optical Instrumentation Engineers.