Polarization rotation and reflection/absorption control using metal-VO2-metal switchable plasmonic metasurface at infrared regime

A plasmonic switchable metasurface is proposed and computed to study multiband reflection/absorption control, polarization rotation and switching characteristics in the infrared regime. The metasurface is made of cylindrical discs of metal-VO2-metal layer pair (LP) with cylindrical air-holes placed appropriately to achieve tunable resonant reflection dips and polarization rotation. For semiconducting (SP) VO2 the metasurface shows double resonant reflection dips at ~ 0.8 and 2.5 microns (due to electric dipole resonance and magnetic resonance, respectively), while metallic (MP) VO2 shows only single resonant dip at ~ 0.8 micron (due to electric dipole resonance). Optimized metasurface (with SP VO2) is capable of rotating reflected light polarization highest by ~ 63° (for high wavelength resonance). In metallic phase (MP VO2), however, no rotation is observed. These observations clearly demonstrate the switching of reflection characteristics and polarization rotation that can be controlled dynamically using thermal excitation. In depth studies are carried out further by systematically varying structural parameters such as periods, LP, angle of incidence, polarization angle of incident light to understand the influential effect on the reflection characteristics and polarization rotation. The novel metasurface has potential implication in light modulation and sensing.