Investigation of the femtosecond inverse Faraday effect using paramagnetic Dy3Al5O12

Pump-probe experiments on the rare-earth paramagnet Dy3Al5O12 demonstrate that coupling between light and magnetism on the subpicosecond time scale cannot be adequately described by the thermodynamic model of the inverse Faraday effect but instead must be described microscopically by stimulated magneto-Raman scattering. Light-induced paramagnetic resonance, predicted by the thermodynamic theory, is not observed in Dy3Al5O12, however, the formation of a coherent superposition between other magnetic sublevels of the Dy3+-ion's ground-state multiplet is measured. It is shown that coherence can only be induced between magnetic levels which are connected by the Raman selection rules.