Theoretical analysis of the Bragg fiber spectral sensitivity in the first and second-order photonic band gaps (PBG)

We demonstrate the theoretical analysis of the propagation properties in a hollow-core Bragg fiber that can be used in bio-sensing applications. Based on the Bragg fiber we propose a resonant sensor that operates on changes in the refractive index of aqueous solution placed inside the hollow-core. We investigate the confinement loss of the TE₀₁ mode. The sensor spectral sensitivity and resolution is presented and compared in the first and second order band gap. We show that fiber sensitivity is higher in the fundamental band gap then in the second-order band gap despite higher confinement loss.