Nonlinear optical properties of Au-Ag core-shell nanorods for all-optical switching

摘要

Au-Ag core-shell nanorods with surface plasmon resonance wavelengths of 760-840 nm were prepared. Wavelength-dependent nonlinear absorption coefficients (beta) and nonlinear refractive indices (gamma) of the nanorods were measured by using Z-scan techniques. The corresponding one-photon and two-photon figures of merit (W and T) were calculated from beta and.. The results show that the requirements of W > 1 and T < 1 for the application of all-optical switching could be achieved for all the samples over a broad wavelength range. These observations make the Au-Ag core-shell nanorods a good candidate for all-optical switching devices.