Surface lattice resonance-based magneto-plasmonic switch in NiFe patterned nano-structure

Abstract In this work, a 2D magneto-plasmonic grating structure combining materials with ferromagnetic and plasmonic properties is demonstrated. NiFe composite ferromagnetic material, as an active medium with tunable physical properties, and Au metal, as a plasmonic excitation layer, were the materials of choice. Here, we have experimentally investigated the active control of the plasmonic characteristics in Au/NiFe bilayer by the action of an external magnetic field, as well as the switching effect of the system. The active plasmonic control, can be achieved by the magnetization switching of the ferromagnetic material, opening a new path in the development of active plasmonic devices. To our best knowledge, this is the first demonstration of such a magneto-optical plasmonic switch based on the coupling of plasmons with magneto-optical active materials, in which the response time was estimated to be in the range of microseconds.