Distributed fibre optics polarimetric chemical sensor

A new distributed fibre optic chemical sensor based on evanescent wave polarimetric interferometry is proposed with the underlying objective to apply the technology to gas chromatography. It allows real-time monitoring of the displacement of a chemical substance along a capillary. Theoretical analysis, modelling and fabrication of a special fibre containing an off-axis capillary is presented. Proof of the principle is experimentally demonstrated with liquid droplets.