Polarization-sensitive optical absorption modulation driven by toroidal-dipole resonance in asymmetric dielectric tetramer metasurface

Abstract

Here we propose a metasurface consisting of asymmetric dielectric tetramer arrays, which can realize a polarization-sensitive light modulation through toroidal dipole resonance (TDR) in the near-infrared (NIR) region. We found, by breaking the C4v symmetry of the tetramer arrays, two narrow-band TDRs can be created with the linewidth around 1.5 nm. Multipolar decomposition of scattering power and electromagnetic field distribution calculations confirm the excitation of TDRs. Our simulation results show that 100% modulation depth in light absorption and selective field confinement can be achieved by changing the polarization orientation of the incident light. Our findings will prompt versatile applications in optical switching, storage, polarization detection, and light emitting devices.