Parametric frequency mixing in the magneto-elastically driven   FMR-oscillator
  We demonstrate the nonlinear frequency conversion of ferromagnetic resonance (FMR) frequency by optically excited elastic waves in a thin metallic film on dielectric substrates. Time-resolved probing of the magnetization directly witnesses magneto-elastically driven second harmonic generation, sum- and difference frequency mixing from two distinct frequencies, as well as parametric downconversion of each individual drive frequency. Starting from the Landau-Lifshitz-Gilbert equations, we derive an analytical equation of an elastically driven nonlinear parametric oscillator and show that frequency mixing is dominated by the parametric modulation of FMR frequency. 
C.L. Chang, A.M. Lomonosov, J. Janusonis, V.S. Vlasov, V.V. Temnov,   R.I. Tobey
cond-mat.mtrl-sci