Comparative performance study of liquid core cylindrical Bragg fibre waveguide biosensors

Abstract

The performance study of various sensing parameters such as sensitivity, detection accuracy and quality parameter of liquid core Bragg fibre waveguide biosensor based on defect mode has been theoretically studied and compared with experimental findings of a similar structure without defect mode. The electromagnetic wave propagation in the present structure has been modelled using the transfer matrix method and Henkel formalism in cylindrical coordinates. The present multilayer structure can provide a band gap between 617 and 929 nm wavelength range at angle of incidence θ= 70 ∘. Due to the presence of a defect layer, a defect mode at 690 nm wavelength is observed in this band-gap region. This defect mode can be treated as a sensing signal in the present study. It is observed that the obtained sensitivity (S≈ 334 nm/RIU) through the defect mode is almost the same as the experimental findings (S≈ 330 nm/RIU) of a similar structure without the defect layer. But the obtained maximum detection accuracy (68.6) and quality parameter (160.4/RIU) of the present structure with defect layer is much larger than the values in a similar structure without defect layer (6.9 and 15/RIU). The present structure having a liquid-filled core, is therefore, favoured and useful in promising biosensing applications. © 2021, Indian Academy of Sciences.