Switchable broadband absorption and electromagnetically induced transparency realized by multilayer metasurface

Abstract Recent absorption and transparency conversion devices often suffer from suboptimal performance due to structural limitations, including narrow bandwidths, limited tunability, and weak slow-light effects. This study addresses these limitations by presenting a novel metasurface design that integrates both electromagnetically induced transparency and electromagnetically induced absorption functionalities onto a platform based on a stacked phase-change material structure. By leveraging a structure incorporating graphene and VO 2 , the proposed metasurface facilitates seamless transitions between transparency and absorption modes. A circuit equivalent model is employed to elucidate the physical mechanism underlying the device’s operation. In the absorption mode, the metasurface achieves a broadband absorption with a bandwidth of 1.72 THz. In the transparency mode, the metasurface demonstrates a significant slow-light effect, characterized by a group delay of up to 7.9 ps and a group index of 95.2. Furthermore, the metasurface demonstrates a four-frequency asynchronous optical switching capability with a maximum modulation depth of 86.2%. Notably, enhancements in absorption bandwidth, group delay, and modulation depth are achieved in comparison to previous work. This research offers new insights for the design of multifunctional optical devices.