Proposal of novel photonic crystal fibre for sensing adulterated petrol and diesel with kerosene in terahertz frequencies

A novel liquid-core photonic crystal fibre (LC-PCF) based on the Zeonex substrate has been proposed for sensing the varying concentration of kerosene in petrol and diesel fuels in terahertz frequencies. Fuel sample infiltration is achieved by designing a single hexagon in the porous core region. The LC-PCF has been numerically studied using a finite element method. By filling the core hexagon with different petrol-kerosene and diesel-kerosene concentrations, sensitivity and transmission profiles of the proposed LC-PCF have been examined. The impact of different design parameters of the fibre on its performance has been analysed, allowing the optimum design parameter set to be selected for further analysis. The proposed fibre shows relative sensitivities above 96% and effective material losses in the order of 10(-3). With negligible confinement losses, the proposed fibre demonstrates near-zero ultra-flattened group velocity dispersion profiles within 1-1.6 THz. It is envisaged that the proposed fibre may be fabricated easily due to its simple design, and thus, serving as a significant step towards understanding THz pulse interaction with liquid petrochemical products.