Wide-range wavevector selectivity of magnon gases in Brillouin light scattering spectroscopy

摘要

Brillouin light scattering spectroscopy is a powerful technique for the studyof fast magnetization dynamics with both frequency- and wavevector resolution.Here, we report on a distinct improvement of this spectroscopic techniquetowards two-dimensional wide-range wavevector selectivity in a backwardscattering geometry. Spin-wave wavevectors oriented perpendicular to the biasmagnetic field are investigated by tilting the sample within the magnet gap.Wavevectors which are oriented parallel to the applied magnetic field areanalyzed by turning the entire setup, including the magnet system. The setupfeatures a wide selectivity of wavevectors up to 2.04\cdot 10E5 rad/cm for bothorientations, and allows selecting and measuring wavevectors of dipole- andexchange-dominated spin waves of any orientation to the magnetizationsimultaneously.