A simple fiber lateral stress sensor based on polarization-maintaining fiber embedded Michelson interferometer assisted by silicon rubber sheets

Abstract

A simple fiber lateral stress sensor is proposed based on polarization-maintaining fiber (PMF) embedded Michelson interferometer (MI). A section of PMF is spliced in the sensing arm of the MI to form the basis of the sensing element. Here the output spectrum will be derived from a two-part interference spectrum: fine part from optical path difference (OPD) of the MI and envelope one from birefringence of the PMF. The PMF is wound into a spiral shape sandwiched by two square silicon rubber sheets, that is the sensing element. Thanks to the low elasticity modulus of silicon rubber material, the experiment show high stress sensitivity of 1.93 nm/kPa in 2.1 kPa stress range by demodulating the envelope shifting. Compared with conventional Sagnac type sensor, the proposed sensor has merits of convenient for application, flexible form, and so on. And this is beneficial for electric power system monitoring