Tunable organic metasurface based on 4-N,N-dimethylamino-4’-N’-methyl-stilbazolium tosylate (DAST) single crystal

4-N,N-dimethylamino-4’-N’-methyl-stilbazolium tosylate (DAST) is one of the most important organic nonlinear optical materials. In this work, a novel low-loss organic metasurface based on DAST single crystal pillar was designed and investigated. Results reveal that this single-layer organic metasurface can achieve near-perfect reflection in the visible to near-infrared. By changing the structural parameters, directional scattering can be tailored as well. Particularly, further design of another reflective organic metasurface, made of a DAST cylinder array and electrically tunable, was examined in detail. With a voltage applied on the metasurface varied from -30 V to +20 V, a continuous tuning of the peak reflection wavelength from 600 to 690 nm with high reflectivity can be achieved, indicative of its potential for uses in filters and dynamic displays.