Tunable linear-to-circular terahertz polarization convertor enabled by a plasmonic nanocomposite metasurface

Abstract

We proposed and demonstrated a metasurface based terahertz polarizer consisting of an optically responsive nanocomposite and a flexible base body, which fulfilled the function of linear-to-circular polarization conversion in transmission mode. Meanwhile, as the dynamic and stretchable materials enable the active manipulation of conversion points, evident frequency shifts for circular polarization transformation were discovered by applying laser irradiation and tension. Hence the modulation of conversion points covered a broadband with combination of those two external excitations. This THz polarization convertor may find its applications in polarization controls and beam steering, which also provides a low-cost and large-scale manufacturable method to achieve versatile active THz devices.