Design of graded topological resonator for sensitivity improvement

Abstract

In this paper, a hyperbolic-graded topological nanophotonic resonator is proposed to excite topologically protected edge states (TES). The index grading is introduced to modify the dispersion characteristics and enhance the mode field confinement of TES. The optimized structure leads to the excitation of a TES at a 1521nm operating wavelength. Further, the structural capability of the refractive index sensor is demonstrated. The analytical results demonstrate a sensitivity of 1806 nm/RIU (with a refractive index range from 1.35 to 1.40). Thus, showing its potential to detect and sense various biochemical analytes accurately.