Electro-optic Modulator Based on Vanadium Dioxide Epsilon-Near-Zero Nanorods Embedded in Silicon Slot Waveguide

We present an electro-optic modulator exploiting a metamaterial made of an array of vanadium dioxide nanorods operating in epsilon near zero regime as the active switching material in a silicon waveguide. The modulator takes advantage of the insulator-to-metal transition of vanadium dioxide together with epsilon near zero to achieve a robust modulation depth of 20.35 dB over a broad range of wavelengths. Using simulations, we demonstrate how the effective permittivity of metamaterial can be tuned to a near-zero value by varying the nanorod geometry. The results provide insight into the design of ultra-compact epsilon-near-zero modulators with high operation frequencies and low insertion losses.