Simultaneous measurement of strain, temperature and vibration frequency using a fibre optic sensor

In this paper, a novel technique for the simultaneous measurement of strain, temperature and vibration for structural health monitoring is demonstrated using a fibre optic sensor system, which combines both a wavelength-swept fibre laser (WSFL) system and a laser diode system using a wavelength division multiplexer. An aluminium beam was placed in a thermal chamber for the simultaneous measurement of its strain, temperature and vibration characteristics. A fibre Bragg grating/extrinsic Fabry-Perot interferometer (EFPI) hybrid sensor system with WSFL was used for the strain and temperature measurements, while the EFPI sensor in the hybrid sensor operated by a laser diode simultaneously measured the vibration characteristics of the beam.