Enhanced magnetic second-harmonic generation in an ultra-compact plasmonic nanocavity.

ABSTRACT: Observation of the second-harmonic generation (SHG) from subwavelength metallic structures is often hindered by the interrelations of higher-order multipolar contributions. In particular, the magnetic Lorentz contribution to SHG is often neglected due to the ineffective magnetic field enhancement in electrically resonant structures. Here, we demonstrate a strong Lorentz-driven SHG output at the plasmon-induced magnetic dipolar resonance in inversion-symmetry-broken plasmonic nanocavities. We observe experimentally tenfold enhancement in the SHG intensity when the magnetic dipole mode is excited, with polarization-resolved measurements confirming the significant role of the hydrodynamic Lorentz-driven second-order nonlinear response. The enhancement originates from a significant spatial ove

SUBMITTER: Wang Y 

PROVIDER: S-EPMC12411620 | biostudies-literature | 2025 Sep

REPOSITORIES: biostudies-literature