Magnetization-induced optical second-harmonic generation and local surface plasmons in magnetic CoxAg1 x nanogranular films

granular films containing Co nanoparticles. A strong resonance of the magneticcontrast of the second-harmonic generation (SHG) intensity is observed in the two-photon energyrange from 3,8 eV to 4,5 eV. The local surface plasmons exited in magnetic Co nanogranules in thisspectral range assist MSHG and are responsible for a significant enhancement of the SHG magneticcontrast due to the resonances of local optical fields.