Tunable Polarization-Independent Terahertz Band-Stop Filter Based on Graphene Metasurface

摘要

A plasmonic band-stop reflective filter based on periodic graphene patch is proposed and numerically investigated using the FDTD method. The proposed filter has a simple three-layer structure, which is composed of graphene, dielectric layer, and metal. Simulated results exhibit that significant absorption peak can be achieved. The absorption spectra can be freely tuned in a broad frequency range by changing the chemical potential. Compared with traditional active filters, this filter does not require mechanical motion, which is suitable for many high-performance situations where stability is a primary concern. Besides, the structure of the filter is ultrathin and reduces the requirements of size and weight. The filter is valid for both transverse electric and transverse magnetic polarization. The filter can be used as a high-sensitivity sensor.