Microstructured optical fibre-based sensors for structural health monitoring applications

We review the state-of-the-art of microstructured optical fibre Bragg grating (MOFBG) sensors for structural health monitoring (SHM) applications. We focus on a specific microstructured optical fibre (MOF) design to which we refer as ‘butterfly’ MOF to illustrate the potential of this technology. This fibre is highly birefringent and encodes pressure and transverse strain into the spectral distance between the two Bragg peaks reflected by a fibre Bragg grating fabricated within this MOF. We discuss possible SHM-related applications of MOFBG sensors, such as cure monitoring and residual strain quantification during composite material manufacturing, shear stress measurements in lap joints and temperature-insensitive vibration monitoring.