High sensitivity D-shaped optical fiber strain sensor based on surface plasmon resonance

A high sensitivity D-shaped optical fiber sensor was designed for strain sensing applications. The sensing properties of the structure were numerically simulated by the finite element method (FEM). The influence of the structural parameters on the sensing performance was investigated. The simulation results revealed that the optical fiber strain sensor displays optimal optical properties with an Au film thickness of 0. 05μm and a distance of 0. 5μm between the fiber core and flat surface. The maximum obtainable strain sensitivity was 2.42×10−5μm/με in the range of 0–1200 με, and it revealed a maximum linearity of R2=0.9964. The proposed D-shaped optical fiber has good sensing properties and potential application in strain sensing devices.