Selective excitations of the multipole moments on a dielectric quadrumer nanostructure using vector polarized Bessel beams

Abstract

The vector polarized Bessel beams possess unique field distributions, which exhibit rich potential for exciting the multipole electromagnetic responses. By using such beams, we demonstrate the selective excitations of high-order multipole responses on a sub-wavelength quadrumer dielectric nanostructure. This work reveals the importance of the geometric relationship between the structure and the distribution of illuminated area of the structured beams for maximizing the desired responses, especially the toroidal dipole response. We believe that our work can provide a new angle for exciting and enhancing the desired multipole responses, which may find potential applications in meta-optics for realizing efficient light–matter interaction.