ABSTRACT
This chapter reviews the various aspects of the nanoscale realization of the All-optical switching (AOS), and demonstrates reproducible all-optical magnetic recording down to 50 nm. It shows that the magnetization reversal in GdFeCo nanostructures for dimensions as small as 200 nm after applying a single, linearly polarized femtosecond laser pulse and without applying any magnetic field. The chapter deals with the question of how structuring down to dimensions comparable to or smaller than the optical wavelength affects AOS key parameters, such as switching speed and fluence threshold. Employing the focusing properties of the structure itself, inhomogeneously absorbed laser energy is obtained at the nanoscale, which in turn triggers inhomogeneous magnetization dynamics. The magnetic state can be toggled back-and-forth deterministically, demonstrating that the optically induced switching is controllable on the nanoscale. The use of plasmonic antenna’s can be an essential ingredient in the realization of all-optical recording at the nanoscale.
