Exponentially index modulated nanophotonic resonator for high-performance sensing applications

Abstract

In this manuscript, a novel photonic crystal resonator (PhCR) structure having an exponentially graded refractive index profile is proposed to regulate and alter the dispersion characteristics for the first time. The structure comprises silicon material, where porosity is deliberately introduced to modulate the refractive index profile locally. The structural parameters are optimized to have a resonant wavelength of 1550 nm. Further, the impact of various parameters like incidence angle, defect layer thickness, and analyte infiltration on device performance is evaluated. Finally, the sensing capability of the proposed structure is compared with the conventional step index-based devices. The proposed structure exhibits an average sensitivity of 54.16 nm/RIU and 500.12 nm/RIU for step index and exponentially graded index structures. This exhibits the generation of a lower energy resonating mode having 825% higher sensitivity than conventional resonator structures. Moreover, the graded index structures show a 45% higher field confinement than the conventional PhCR structure.

New features of the surface wave propagation along an exponentially graded-index layer and nonlinear substrate with generalized Kerr-type nonlinear response

“…Method of thermal diffusion of ions silver Ag + on the glass produces a layer with a profile, which is a close approximation an exponential one [24]. Note also, that an exponential spatial profile of the refractive index is produced recently in photonic crystal resonators [46]. Thus, by combining the optical materials mentioned above, we could obtain a contact with optical properties close to those described by us under certain conditions and characteristics of the laser radiation exciting the surface wave.…”

Nanophotonic Resonator Assisted Photonic Spin Hall Enhancement for Sensing Application

“…The PSHE-TD can also be enhanced considering multilayered photonic crystal-based nano-devices because of their light-controlling properties 28 . These devices have witnessed considerable growth in demand in various exciting applications over the last few years, including biomedical diagnostics, liquid/gas sensing, and environmental monitoring 29,30 . These nanostructures can be optimized to manipulate light-matter interactions, suppressing a particular polarization.…”

Design of graded topological resonator for sensitivity improvement

“…There is tremendous research going on to explore the capability of nanophotonic resonators because of their inherent property to confine an optical mode at the nanoscale range [1][2][3]. These have been designed for a broad range of applications, from smart cities to smart healthcare [4][5][6][7].…”

“…These have been designed for a broad range of applications, from smart cities to smart healthcare [4][5][6][7]. Further, the device performance can be improved by considering the graded refractive index profile along with the thickness of the material [ 8,9]. The graded resonators differ from homogeneous materials in that they contain distinguishing characteristics along with an extra degree of design freedom.…”