Surface Plasmon Resonance Tunability in Au−VO2 Thermochromic Nano-composites

A new type of photo-active nano-composite material appropriate for Ultra-fast Nonlinear Optical χ(3) (ω) applications has been synthesized and optically characterized. Compared to standard noble metal particles- oxide nano-composites exhibiting a superior effective χ(3) (ω) due to the enhancement of the local electric field, these Au−VO2 nano-composites display an additional reversibly tunable surface plasmon frequency under external temperature stimuli. Such a smart plasmon tunability is correlated to the Mott’s type semiconducting/metallic 1st order transition of the host VO2 matrix. The nano-gold surface plasmon wavelength shifts reversibly from 645 nm to 598nm when the Au−VO2 nano-composites temperature varies from 25°C to 120°C.