Design of a High-Efficiency Reconfigurable Anomalous Transmission Metasurface Using Sb2Se3

Reconfigurable metasurfaces (R-MTSs) exhibit significant potential for wireless optical switching due to their compact size and rapid beam switching capabilities. However, conventional R-MTSs based on micro-electro-mechanical systems, electrochemical, or chemical reactions often suffer from high losses and bulky dimensions. In this study, we propose a novel R-MTS design utilizing the low-loss phase-change material Sb2Se3. By modulating the crystalline and amorphous states of Sb2Se3, the metasurface achieves reconfigurability. Notably, under circularly polarized light (C-band), it generates two symmetrically high-efficiency anomalous transmission beams corresponding to the two phase states of Sb2Se3. Simulation results indicate that our design covers an angular range of approximately 34.2° through the Sb2Se3 state transition, maintaining a transmission rate >85.3% and polarization conversion efficiency >96.2%.

I. Introduction

In the information age, wireless optical switching (WOS) technology has significantly advanced optical communication and established a robust foundation for high-performance information interaction and processing [1], [2]. Traditional WOS units, such as Micro-Electro-Mechanical Systems (MEMS) [3], are inadequate for future large-scale WOS due to their complex serial control and high energy consumption from external voltages. Consequently, researchers are focusing on reconfigurable metasurfaces (R-MTSs) to design WOS units [4], [5], [6]. R-MTSs consist of two-dimensional arrays of metamaterials with subwavelength-scale dimensions. By tailoring the parameters of meta-units, the interaction between surrounding electromagnetic waves and incident light fields can be induced [7], [8], thereby eliciting local resonances and effecting changes in amplitude and phase gradients to enable agile manipulation of light waves [9], [10], [11]. This facilitates functionalities such as spin-orbit angular momentum conversion [12], anomalous reflection beam deflection [13], reconfigurable optical switching [14], and broadband angular spectrum differentiation [15].