Triple-Band and Ultra-Broadband Switchable Terahertz Meta-Material Absorbers Based on the Hybrid Structures of Vanadium Dioxide and Metallic Patterned Resonators.

A bifunctional terahertz meta-material absorber with three layers is designed. The surface of the bifunctional meta-material absorber is a periodically patterned array composed of hybrid structures of vanadium dioxide (VO) and metallic resonators; the middle layer is a nondestructive TOPAS film, and the bottom layer is a continuous metallic plane. Utilizing the phase-transition property of VO, the responses of the meta-material absorber could be dynamically switched between triple-band absorption and ultra-broadband absorption.