Liquid-Crystal-Based Electrically Tuned Electromagnetically Induced Transparency Metasurface Switch

In this study, a structure to realize a switchover between two different responses of electromagnetically induced transparency (EIT) was designed and implemented by simulation. Taking advantage of the anisotropy in the structure and the coupling between the radiative and dark elements, a metasurface switch with modulation depth of over 85% between orthogonal polarization incident light illuminations was demonstrated. The key mode switchover between the "on" and "off" states was achieved by electrically changing the dressing light polarization with a liquid crystals layer pre-aligned with a mature technology, without changing the incident light and an expected and reversible transition from an EIT-like spectrum to a strong spectral dip was observed. The modulation in the EIT switch fabricated with the proposed straightforward approach is a promising tool to control the groping velocity delay.