Filtering and Modulation from Visible to Terahertz using Phase-Change Extraordinary Optical Transmission Metasurfaces

Abstract

Periodic arrays of sub-wavelength-scale holes in plasmonic metal films are known to provide resonant transmission/reflectance peaks via the extraordinary optical transmission (EOT) effect. Active control of the spectral position of such transmission/reflection peaks can be obtained by adding a layer of phase-change material (PCM) to the EOT device. Switching the PCM layer between its amorphous and crystalline states shifts the spectral position (and usually the amplitude too) of the resonance, so enabling potential applications in the fields of active filtering and sensing (e.g. for multispectral imaging) and optical modulation. Here we report the design, fabrication and characterization of active EOT devices targeted at various important regions of the optical spectrum