OBSERVATION OF CROSS-PHASE INDUCED MODULATION INSTABILITY OF TRAVELING MAGNETOSTATIC WAVES IN FERROMAGNETIC-FILMS

Modulation instability, induced by the simultaneous propagation of two magnetostatic spin waves in ferromagnetic films, has been experimenta lly observed for the first time. The effect is caused by cross-phase m odulation and the spectra of transmitted waves contains sidebands, sym metrically positioned either side of the carrier frequency. They appea r as the wave power reaches a threshold value, and disappear when only one wave is present. This is the signature of cross-phase modulation. The dependence of the modulation frequency upon the wave power and fr equency is reported and a theoretical explanation of the observed phen omenon, using nonlinear Schrodinger coupled equations, is presented.