Interrogating the Structure of Molecular Cavity Polaritons with Resonance Raman Scattering: An Experimentally Motivated Theoretical Description

The formation of exciton polaritons by strongly coupling molecular electronic transitions to spatially confined photons may change photochemical processes. However, the fundamental physical drivers of these proposed changes remain unclear. To understand the role of changes to the molecular structure caused by polariton formation in these photochemical processes, we develop an experimentally motivated theoretical description of resonance Raman scattering from exciton polaritons. By modeling the structural parameters of light absorption in zinc tetraphenyl porphyrin and exciton polaritons formed from this molecule in nanostructured Fabry-Perot cavities, we simulate resonance Raman scattering excitation spectra from exciton polaritons and assess how these spectra depend on the polariton characteristics. We find that the detuning of the cavity mode energy from that of the molecular transition can affect the structure of the resulting polaritonic states, as inferred from our simulated spectra. We also find previously unreported interference effects between the quantum paths contributing to the resonance Raman scattering pathways changes in the presence of exciton polaritons. Finally, we discuss possible experimental configurations capable of extracting the predicted polariton spectral signatures from the background of the signal from molecules not participating in strong cavity-molecule coupling. These results suggest resonance Raman spectroscopy could be a powerful tool to assess the role changes to the molecular structure plays in the amended photophysics and photochemistry of exciton polaritons.