Brillouin Light Scattering Revisited

Since the 80’s, when Brillouin light scattering emerged as a powerful tool for investigating magnetization dynamics in thin films and multilayers, it developed into a versatile microscopic probe for studying collective spin excitations. Following a short introduction on studies of millimeter-sized films, we will give examples how to investigate individual magnetic structures down to tens of nanometers in dimension. We will introduce the concepts of time- and phase-resolved Brillouin light scattering which give full access to the spatio-temporal evolution of the optically accessible spin-wave spectrum. During our talk, we will provide hands-on demonstrations how to drive spin waves via spin currents and microwave excitations in magnetic nanostructures using the build in dc/ac probe station in our laboratory and show the capabilities of Brillouin light scattering for quantifying spin-wave phenomena. Furthermore, we will highlight similarities and differences to other optical scanning probe techniques such as time-resolved magneto-optical Kerr microscopy and optically detected magnetic resonance based on vacancy centers. We will outline how those techniques can potentially be combined with Brillouin light scattering to access complementary information.