Fig. 5: Rabi splitting as a function of frequency detuning between the PMMA vibrational mode and the metasurface resonances.
From: Trapping light in air with membrane metasurfaces for vibrational strong coupling
a Spectra showing the VSC between the PMMA molecules’ C = O vibrational transition (shaded gray) and the qBIC TM modes, which are spectrally tuned to various wavenumbers. Spectra collected before coating the metasurface with PMMA (dashed gray lines) and after coating (solid-colored lines) are shown. Experimentally measured spectral responses show polariton formation and Rabi splitting at varying values due to resonance detuning as the qBIC mode sweeps the C = O absorption band. Vertical offsets were applied to improve clarity. b The experimentally measured Rabi splitting values plotted as a function of resonance detuning show the zero-detuning wavenumber at the minimum Rabi splitting value. c, d The anti-crossing behavior, a signature of VSC, was observed both in experimental measurements (c) and simulation results (d). The gray dashed line represents PMMA C = O bond’s absorbance resonance and the pink dashed line represents unperturbed qBIC TM resonances, respectively.
