Second-Harmonic Generation from a Magnetic Buried Interface Enhanced by an Interplay of Surface Plasma Resonances

Abstract

Magnetization-induced second-harmonic generation (SHG) enhanced by surface plasma resonances (SPRs) is studied in a Au/(Bi,Tm) iron garnet (IG) perforated magnetoplasmonic crystal capable of sustaining SPRs at both air/Au and Au/(Bi,Tm)IG interfaces. Asymmetry of a crossing point of the SPR branches is shown, demonstrating a significant difference in the SHG spectra at both sides of the complex resonance. Despite the thick (120 nm) Au layer, the sensitivity of the SHG to the SPR at the buried Au/garnet interface is demonstrated through observing an SHG magnetic contrast, when the SHG is amplified by an excitation of the SPR at the bottom interface.