All-Optical Multipulse Pump-Probe Method for Selective Control of Magnetization Precessions in Magnetic Multilayers

A method to all-optically selectively excite and probe individual resonances within a multimodal system is demonstrated. As an example, the method is applied to control spin waves within a multilayer magnetic structure. By tuning the timing of two femtosecond pump pulses, the magnetization precession of a particular spin wave resonance can be selectively quenched while maintaining the precession of the other. This control depends on the relative positions of the magnetization vectors within their precessional trajectory and on the power ratio of the pump pulses. A representation of the position of the vectors in the complex plane is introduced, which serves as a convenient means for manipulation of the systems.