A dynamically tunable chiral mirror enabled by electrochromic metasurfaces operating at telecommunication wavelengths

In this paper we introduce the concept of tunable chiral mirror and provide an experimental evidence of its implementation. A chiral mirror, i.e., a device which reflects circularly polarized light of a single handedness without inverting it, has been synthesized by numerical optimization of a metasurface composed of non-centrosymmetric meta-atoms. Operation has been targeted to the telecommunication wavelength through a judicious rescaling and reshaping of the meta-atom geometry. Embedding an electrochromic material (V2O5) in the layer stack, dynamical reconfiguration of the chiral mirror has been achieved, with a theoretical modulation depth of more than 35 dB. Reconfiguration is self-holding and reversible, showing that electrochromism in V2O5 could prove to be a powerful tool to modulate the response of complex beam shaping and polarization handling metasurface-based ultrathin photonic components.