We propose a simple analytical formula that can quantitatively predict resonant light scattering from metal nanoparticles of arbitrary shape, whose sizes are too large for Rayleigh approximation to be applicable. The formula has been derived as an empirical extension of Mie’s rigorous calculation for light scattering from spheres. It can very well reproduce the experimental characteristics of light scattering from Au nanorods.
Light scattering by individual Ag nanoparticles and structures have been studied spectroscopically. Individual particles were selected and manipulated with a micromanipulator installed inside a scanning electron microscope (SEM). With typical particle dimensions of some 100 nm, the plasma resonances of particles and the coupled modes of particle pairs were observed in the visible region. The polarization dependence of the resonance frequencies strongly reflects the shape anisotropy; the effect that would be averaged out for experiments on ensembles. With a simple approximation to take the glass substrate into account, the results are in good agreement with the analytical calculations by Mie scattering, and with numerical calculations by the finite-difference time-domain method, both of which are performed with the morphological parameters obtained from the SEM observation for the corresponding particle or particle pair.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.