Vasić Borislav, Gajić Radoš
Opt Lett. 2017 Jun 1;42(11):2181-2184. doi: 10.1364/OL.42.002181.
While previous tunable metasurfaces were based mainly on tuning of dielectric permittivity or losses in associated tunable elements, here we propose gain-assisted tunable metasurfaces as optical modulators with high ON-OFF ratio. They consist of a dye-doped film placed within metal-insulator-metal (MIM) cavities. Plasmonic modes with enhanced electric field significantly enhance both absorption and emission of light by dye molecules. As a result, it is possible to achieve the perfect absorption in MIM cavities with zero reflection, as well as to compensate losses thus achieving unit reflection. As a result, the achievable ON/OFF ratio is more than 100.
虽然先前的可调谐超表面主要基于相关可调谐元件的介电常数或损耗的调谐，但在此我们提出增益辅助可调谐超表面作为具有高开-关比的光调制器。它们由置于金属-绝缘体-金属（MIM）腔体内的染料掺杂薄膜组成。具有增强电场的表面等离激元模式显著增强了染料分子对光的吸收和发射。结果，有可能在MIM腔中实现零反射的完美吸收，以及补偿损耗从而实现单位反射。因此，可实现的开/关比超过100。
