Effect of Tunable Dielectric Properties of the Core on Optical Bistability within Spherical Composite of Metal and Dielectric Nanoparticles

Abstract

This paper explores how tunable dielectric properties in the core influence the enhancement factor of the local field, induced optical bistability, and its domain in spherical metal-dielectric nanocomposites. Mathematical expressions were derived for the electric potentials governing these nanocomposites using the quasi-static solution of Laplace's equations. The equation for optically induced bistability was obtained through the enhancement factor of the local field equation, incorporating the Drude-Lorentz model. By varying the dielectric properties of the core and the volume of the metal coating on the inclusions, the enhancement of the local field significantly increases at two resonant frequencies when an additional dielectric function is introduced into the active dielectric core. Specifically, the enhancement factor of the local field increases with more dielectric function in the imaginary component of the active dielectric of the core. Furthermore, by comparing three different local field values to a single applied field value, we observe that the bistability region expands with increasing dielectric function in the imaginary part of the active dielectric core, enhancing oscillatory behavior in the system. These findings have potential implications for advancements in optical controls, memory chips, sensor technologies, and logic operations.