Brillouin light scattering (BLS) is an optical measurement technique for the investigation of microscopic dynamics of solids. It is used to investigate the frequency of magnetization dynamics, e.g. propagating spin waves. The basic principle reposes on the inelastic scattering of photons with spin waves. This can be understood as the creation and annihilation of them. The result is energy win or loss of the scattered laser light and therefore a change in frequency, which is analyzed. The change in frequency of the laser light is equal to the frequency of the spin waves. For higher spatial resolution the light is focused by a microscope objective in BLS microscopy experiments (µBLS). Due to the distribution of the angles of incidence, the information about the wave vector of the spin waves becomes uncertain. The loss of this information can be recovered by phase resolved µBLS measurements.
HZDR Department of Magnetism - Junior Research Group Magnonics