Interactions of Fundamental Mie Modes with Thin Epsilon-near-Zero Substrates

Strong Coupling of Resonant Metasurfaces with Epsilon-Near-Zero Guided Modes

“…It usually exhibits that the Rabi splitting strength will be enlarged as the thickness of the ITO layer increases (Supporting Information, Figure S3), which is consistent with previously reported results . Of concern is that LP shows lower transmittance compared to UP due to the loss of ITO as well as the asymmetry in the depth of the transmission resonance, which is consistent with the case of strong Mie-ENZ coupling in dielectric nanoresonators . Such a strong QBIC-ENZ coupling with large coupling strength can be attributed to the strong localized field around the nanorods and a sufficient field overlap at the QBIC resonance, leading to strong field enhancement at both UP and LP resonance within the ITO layer, as shown in Figure (e) (also see Figure S2 middle and right panel in Supporting Information for more details).…”

“…High-index dielectric nanoscale resonators represent an attractive alternative for the realization of strong-coupling-enhanced nonlinear effects . Compared to their plasmonic counterparts, dielectric nanostructures exhibit low optical losses combined with high radiation efficiency and complementary metal oxide semiconductor compatibility. − Importantly, dielectric nanostructures can support optical Mie resonances, allowing for enhancement of both the electric and magnetic near-fields. , Strong coupling between ENZ mode of an ultrathin ITO film and Mie resonances has been reported with a large effective optical nonlinear coefficients and ultrafast nonlinear response of the system at the coupled resonances. , …”