New nonlinear phase transduction method for DC measurand interferometric fibre sensors

Abstract

A new approach to the measurement of displacement using optical fibre interferometry is described. The technique is based on a geometrical arrangement in which linear displacement is transposed nonlinearly into axial fibre strain. The technique can be used in the development of true DC sensors for the displacement, acceleration, pressure and other variables. A displacement sensitivity of ˜4 Å is demonstrated.