Strong coupling between plasmonic Fabry–Pérot cavity mode and magnetic plasmon

We demonstrate strong coupling between the Fabry-Pérot cavity plasmons and magnetic nanowire plasmons. The strong coupling leads to drastic enhancement of magnetic field intensity beneath a silver nanowire inside a metallic cavity. A Rabi splitting of 280 meV and a magnetic field intensity enhancement of 845 times the incident is achieved using the proposed geometry. The theoretical prediction agrees well with rigorous full wave simulations. The effect provides efficient tools for applications such as magnetic nonlinearity and magnetic sensors.