Brillouin light scattering from pumped uniform-precession and low-k magnons in Ni81Fe19
Ward L. Johnson, Sudook A. Kim, Stephen E. Russek, Pavel Kabos
A method is presented for performing Brillouin-light-scattering measurements on uniform-precession and low-wave-number (Iow-k) magnons excited by a microwave magnetic field in opaque magnetic specimens. The optical configuration is similar to that employed in conventional 180^0 backscattering measurements, except that the incident and specularly reflected beams pass through the collection lens along different parallel paths. Examples of spectra from Ni_81 Fe_19 are presented, which include the first observation of pumped low-$k$ magnons arising from microwave excitation in a metallic film.