Static stress optical-fiber sensor

Abstract This sensor is based on the mode coupling between two optical fibers. It uses standard multimode optical fibers, fused along a fixed clad length parallel to the fiber axis. The sensor is integrated in an epoxy-resin material and submitted to a static pressure, causing the light to be coupled from one fiber to another. It exhibits a coupling coefficient variation in the range of 4 × 10 -3 MPa -1 that depends on the sensor parameters, and a low temperature sensitivity. The sensor is devoted to civil-engineering applications such as concrete shrinkage, weighing bridges and monitoring.