A simple strain sensor using a thin film as a low-finesse fiber-optic Fabry–Perot interferometer

Abstract

A simple extrinsic optical-fiber strain sensor that uses a thin transparent elastic polymer film acting as a low-finesse Fabry–Perot interferometer has been developed and tested. The polymer is mounted at the end of a multi-mode optical fiber as a strain sensitive element. The strain resolution of the sensor is 2×10 −6, the accuracy is 5×10 −6 over dynamic range 0–5000×10 −6.