All-optical ultrafast tunable linear absorption with a VO2 based metamaterial

The phase-dependent plasmonic response of a metamaterial platform composed of VO2 nanocrystals (NCs) embedded in an SiO2 matrix was investigated using ultrafast time-resolved spectroscopic ellipsometry. Localized surface plasmon resonances (LSPR) emerged upon excitation with 35 fs laser pulses at λ = 500 nm, which triggered the insulator-to-metal transition in the VO2 NCs. The study reveals the ultrafast dynamics mapped at the LSPR underlying the photoinduced optical tunability of the system, highlighting the potential of VO2 NCs for reconfigurable photonic applications such as tunable linear switching.