Reconfigurable Molecularization of Terahertz Meta-Atoms

Abstract

Active terahertz metamaterial devices with controllable resonance proper-ties have been commonly investigated. However, owing to the limited tunability of theirfrequencies and low-quality factor resonances, these devices are difficult to adopt as single-devicefilters that can actively adjust diverse spectral information. Moreover, they typicallyrequire complex instrumentation for regulating terahertz waves. In this paper, we proposereconfigurable molecularization of terahertz meta-atoms allowing on-demand realization ofresonance characteristics in a single active terahertz metasurface. This is achieved byselectively controlling the electrical connections between the meta-atoms usingmicropatterned ion-gel gating structures. Based on this operation scheme, the resonancecharacteristics of the terahertz metamaterial can be controlled electrically, and it can serveas a multistate, transmissive metamaterialfilter with resonance frequencies tunable from 0.5to 1.3 THz. In addition, the reconfigurable molecularization of terahertz meta-atoms allowsproducing a transmissive metamaterial showing controllable transmission resonance toterahertz waves. Exploiting the versatility of an active metasurface, we demonstrateterahertz dichromatic vision distinguishing different saccharides without using spectroscopy systems