Plasmon resonance enhanced large third-order optical nonlinearity and ultrafast optical response in Au nanobipyramids

摘要: The third-order optical nonlinearity and response time of Au nanobipyramids have been investigated by using Kerr effect technique. Large nonlinear susceptibility (χ(3)) ultrafast obtained at the longitudinal surface plasmon resonance (LSPR) wavelength. As excitation laser wavelength varies from non-resonance 780 nm to LSPR 825 nm, χ(3) increases 7.4 × 10−14 3.9 × 10−13 esu, fast component decreases 141 ± 23 83 ± 8 fs ratio remains around 48%, while slow 3200 ± 200 2310 ± 158 fs. large enhancement is due local field caused resonance, shortening times are induced increased probability electron-electron electron-phonon scatterings in nanosystem. This significant property nanobi...