A terahertz Fabry-Pérot modulator using charge injection-induced insulator-metal transition in vanadium dioxide

Abstract

We report the use of Insulator-Metal Transition (IMT) of vanadium dioxide (VO₂) to modulate Fabry-Pérot resonances in a terahertz Fabry-Pérot resonator. Our two-plate Fabry-Pérot modulator consists of one partially reflecting plate of monolayer graphene on a polymer substrate, and another plate of VO₂-integrated copper electrodes. VO₂, a strongly correlated electron system, undergoes IMT upon application of external stimuli. In our Fabry-Pérot modulator device, we stimulated VO₂ IMT by injecting charges into the VO₂ via copper electrodes to realize a terahertz modulator. With 500mA DC at 12 V, we obtained 50% amplitude modulation depth at 0.884 THz.