Abstract
Ge2Sb2Te5 (GST), as a typical non-volatile phase change material, is regarded as a strong candidate for designing reconfigurable metamaterials, while most of them reported to date operate in visible and near-infrared regions, providing only a single-function while neglecting polarization controllability. This article presents an integrated multifunctional GST-based reconfigurable terahertz metamaterial with joint polarization control, consisting of an Al-based patterned array placed on a continuous GST film separated by a middle polyimide layer. The conductivity of GST undergoes significant changes during thermal controlled phase transition process, enabling the meta-device to dynamically switch from single-band electromagnetically induced transparency to triple-band near-unity absorption. Importantly, changing incident beam polarization direction, two more functions, single-band filtering and single-band near-perfect absorption, are further obtained, achieving finally four different and excellent functions, and each function could be dynamically modulated by applying different annealing temperatures, obtaining 77% amplitude modulation and up to 700% relative modulation performance, which is far superior to previously reported single-function reconfigurable terahertz meta-devices. Numerical simulations maintain a high degree of consistency with experimental results. Owing to the simplicity, ease-of-manufacturing, rich-functional compatibility, polarization multiplexing, and excellent amplitude adjustability, the terahertz metamaterials are expected to have broad applications in optoelectronic modulators, and intelligent switches.