Optimizing temperature-dependent molar volume fraction of biodiesel fuel in a pseudo-binary mixture through Bragg fiber waveguide sensor having defect layer

Abstract

In the present communication, the temperature-dependent molar volume fraction of various kinds of renewable biodiesel fuel resources in a pseudo-binary mixture is theoretically optimized through the Bragg fiber waveguide (BFW) sensor with a geometrical defect in periodic cylindrical Bragg reflectors. BFW structure is modelled using a transfer matrix method (TMM) and Henkel formalism in a cylindrical coordinate system. The temperature dependence molar volume fraction is linked to the change in the refractive index of the pseudo-binary mixture, which is further predicted using the capacity of various models; Lorentz-Lorenz, Dale-Gladstone, Eykman, Newton, and Kay. In the presence of a geometric defect layer, a sharp transmission peak of 0.1nmfull width at half maxima (FWHM) is obtained in the considered photonic band gap (PBG), which is sensitive to the change in core refractive index. The temperature-dependent (due to different weather conditions) maximum sensitivity of the proposed sensor is found to be 1280 nm/RIU, which is further compared with the phoxonic crystal-based static temperature sensor having sensitivity 142 nm/RIU only. Along with improved sensitivity in the proposed sensor, other sensing performance parameters detection accuracy and quality parameter (which are inversely proportional to the FWHM) are also improved due to least FWHM of resonant transmission peak about 0.1 nm comparatively. © 2021 Elsevier Ltd