Time resolved nonlinear surface plasmon optics

A new surface-sensitive method of time-resolved optical studies is proposed. The method consists in the independent excitation of several surface electromagnetic waves (SEW) by two laser femtosecond pulse beams with varied time delay $\Delta\tau$ and distance $\Delta r$ between corresponding excitation regions on surface. To fulfill phase matching condition for plasmon-photon coupling metal grating is used. Due to nonlinear plasmon interaction, the optical radiation with $\omega_1+\omega_2$ and $2\omega_1-\omega_2$ (where $\omega_1,\, \omega_2 $ are correspondent laser beam frequency) is generated. The intensity of this nonlinear response versus $\Delta\tau$ and $\Delta r$ are studied. The direct measurements of the SEW temporal properties are presented. Experiments of this type are important for the development of the femtosecond surface plasmon optics.