Direct Detection of Nonlinear Ferromagnetic Resonance in Thin Films by the Magneto-Optical Kerr Effect

摘要

The longitudinal magneto-optical Kerr effect is used to obtain a calibrated measure of the dynamic magnetization response over the ferromagnetic resonance (FMR) profile for in-plane magnetized Permalloy films excited with high power in-plane transverse microwave fields at 1.25 to 3.75 GHz and in-plane precession angles up to about 20°. The data provide a profound demonstration of the Suhl threshold effect for parametric spin wave generation for angles above about 14°, the magnetization precession lock-up just above threshold, and the complicated response over the full FMR profile at very high powers.