Plasmon-induced magnetization of metallic nanostructures

Plasmon-induced magnetism of nanostructured metallic samples has been studied. Magnetic force microscopy measurements show that magnetization of a nanohole array can be achieved by illumination of the structure at the wavelengths corresponding to various surface plasmon excitations. This second-order nonlinear optical effect appears to affect propagation of light through an array of such nanoholes in a gold film as observed by spectroscopic measurements in external magnetic field. This effect can find numerous applications in magneto-optical data storage and optical communication and computing.