Reflective polarimetric vibration sensor based on temperature-independent FBG in HiBi microstructured optical fiber

摘要: Fiber optic sensors outperform traditional sensor technologies in fields such as structural health monitoring, vibration and seismic activity intrusion detection, many other applications. Their key advantages include electromagnetic interference immunity, lightweight, small size, multiplexing capabilities, low power consumption, corrosion high temperature resistance. To meet the demand of more challenging optical a new generation fibers, so-called microstructured fibers (MOFs), has appeared. These are composed structure holes surrounding solid core, which offers unique design flexibility to optimize their waveguide properties for specific In particular, can be optimized strongly reduce cross-sensitivity parasitic physical parameters like variations, is case presented here. Our based on Bragg grating inside independent highly birefringent MOF with transverse strain sensitivity, evaluate vibrations by polarimetric measurement reflection spectrum. This technique takes advantage stress-induced phase shift between two orthogonally polarized fiber eigenmodes. It consists coupling linearly light through one arm an coupler (50:50) sensing reflective inscribed. The reflected signal analysed linear polarizer. crushed mechanical transducer designed transform into stress transversal fiber’s axis. therefore induces change modal birefringence that varies time at frequency. this study we show using standard single-mode realize do not provide stable measurements conventional polarization-maintaining lead significant temperature. We then use type allows (up 120°C) repeatable measurements.