Broadband and strength-switchable circular dichroism in a GeSbTe-based metasurface.

Circular dichroism (CD) is highly required in the applications of biological detection and analytical chemistry. In this paper, we achieved a giant, broadband, and strength-switchable CD effect in a quadruple -shaped (GST) metasurface. At the amorphous state of GST (a-GST), the giant CD reaches 0.

Enhanced circular dichroism in GeSbTe-loaded metasurface.

Circular dichroism (CD) is originally obtained from three-dimensional spiral structures by simultaneously exciting electric and magnetic resonances. To simplify construction, multilayer stacked asymmetric structures and the symmetric structures relying on oblique incidence are proposed for enhancing CD. Herein, we achieved the enhancement of dual-waveband CD by adding a GeSbTe (GST) layer on the top of a Z-shape gold array in a normally incident system.

Multifunctional metasurfaces for switchable polarization selectivity and absorption.

A multifunctional metasurface capable of dynamic control for polarization selectivity and absorption is proposed by controlling the phase of GeSbTe (GST) in the near-infrared region. At amorphous state of GST (a-GST), the proposed GST strip array realized polarization selectivity in transmission-reflection integrated modes. The high-efficiency asymmetric transmission (AT = 0.

Design and simulation of a GST-based metasurface with strong and switchable circular dichroism.

Circular dichroism (CD) is required in the applications of biological detection, analytical chemistry, etc. Here, we numerically demonstrated large-range switchable CD by controlling the phase change of GeSbTe (GST) in a zigzag array. At the amorphous state of GST (a-GST), the strong and dual-waveband CD effects are realized via the selective excitations of electric, magnetic, and toroidal resonances.