Adhesive Based Fabry-Pérot Hydrostatic Pressure Sensor With Improved and Controlled Sensitivity

In this paper, we demonstrate both numerically and experimentally the capability to control and enhance the hydrostatic pressure sensitivity of an adhesive based Fabry-Perot (FP) sensor. The fiber sensor consists of a polymerized resin in between two single-mode fiber terminals that act as low-reflectance mirrors. The theoretical evaluation of the proposed sensor showed that the strain in the region between the fiber end faces increases with increasing dimensions of the resin structure surrounding the inner FP cavity. Experimentally, the photopolymerizable resin was added in layers, increasing the structure dimensions, allowing to improve the hydrostatic pressure sensitivity from 102 to 475 pm/MPa for the cavity filled with resin just in between the fiber end faces and for the cavity covered with several layers of resin, respectively. The sensor fabrication is simple and cost effective, allowing an easy and affordable way to control and enhance the hydrostatic pressure sensitivity of resin based FP sensors.