Omnidirectional tunable terahertz analog of electromagnetically induced transparency realized by isotropic vanadium dioxide metasurfaces

We present an isotropic active analog of electromagnetically induced transparency through conductivity tuning of vanadium dioxide at terahertz frequencies The unit cell of the designed metasurface consists of metallic split ring resonators and a metallic cross, which have identical resonance frequencies for the excitable lowest order modes but very different linewidths. By integrating vanadium dioxide into the bottom of the metasurface, an obvious tuning of the transparency window occurs under different conductivities. Calculated results show that resonant transmission frequency of the electromagnetically induced transparency remains stable with respect to the polarization and incident angle of electromagnetic waves. (C) 2018 The Japan Society of Applied Physics