This paper proposes and demonstrates a multilayered epsilon-near-zero (ENZ) metamaterial using Si-compatible titanium nitride and indium-tin-oxide materials. The device achieves ultrafast (a few hundred femtoseconds) all-optical switching at two wavelengths (visible and near-infrared) using minimal energy via intraband pumping. This approach offers potential for low-power ultrafast all-optical terahertz modulation and new hybrid integrated photonic components.
