Sensitivity of whispering gallery modes with different physical parameters of hollow microspheres: a theoretical study

Abstract

Herein, we report the theoretical investigation on whispering gallery modes (WGMs) of dielectric hollow microspheres (hollow core-shell microspheres) illuminated by plane wave and focused Gaussian beam (FGB). In the case of plane wave illumination, the wavelength sensitivity of the WGMs with different parameters of the hollow microspheres such as radii of the core and the shell, refractive indices of the core and the shell, and shell thickness is studied systematically. The variation in the electric field and quality factor of the WGMs with the above-mentioned parameters is also investigated. In the case of FGB illumination, the effect of beam waist on the characteristic parameters of the WGMs is studied. Later, the merits of the core-shell microspheres for the refractive index sensing applications over the solid microspheres are explained. Finally, the characteristic parameters of the WGMs of solid core-shell microspheres are studied.