Voltage-induced beam switching by a geometric phase metasurface incorporated into a Tamm plasmon polariton structure

Diffraction orders at the Pancharatnam-Berry metasurface are efficiently switched by applying voltage. A liquid crystal layer introduced acts as a half-wave phase plate to exchange left- and right-circular polarizations of light. Applied voltage turns the polarization exchange on and off, causing redistribution of the intensity between the -1 and +1 diffraction orders. The proposed novel, to our knowledge, structure features a multilayer substrate that supports the Tamm plasmon polaritons, enabling the integration of both resonant and non-resonant phase-change mechanisms.