Simultaneous Static Strain, Temperature and Vibration Measurement Using an Integrated FBG/EFPI Sensor

A novel technique for simultaneous measurement of static strain, temperature and vibration in health monitoring of structures is demonstrated using an integrated in-fibre Bragg grating (FBG)/extrinsic Fabry-Pérot interferometer (EFPI) sensor. The EFPI sensor provides static strain and vibration information simultaneously by using the channel-spectrum method and the low-coherence interferometric technique, respectively. The FBG sensor is used for temperature measurement. The experimental results show that a static-strain accuracy of ±20µε, a temperature accuracy of ±1°C and a vibration resolution of 1 nm have been achieved with a good repeatability.