Enhanced asymmetric transmission of linearly polarized light based on all-dielectric stereometamaterial

Abstract

Abstract Reciprocal asymmetric transmission (AT) phenomenon has received much attention due to various polarization applications, however, high-efficiency AT still remains out of reach in the optical range. In order to improve AT of linearly polarized light, low-loss dielectric metamaterial with twisted resonators should be designed and investigated. The stereometamaterial is constructed by an array of bilayer 90° twisted H-shaped Ge dimers. Based on the transmission matrix, numerical simulation and multipolar resonances analysis, the polarization responses in all-dielectric stereometamaterial are characterized. The simulated results show that the AT parameter reaches up to 98% around 194 THz. In addition, the AT can be engineered via geometrical parameters. The proposed stereometamaterial also exhibits strong circular dichroism that is direction-independent. The multipole decomposition calculations can be utilized to understand the resonant mechanism.