Molecular cavity polariton formation using multimode resonator structures

Abstract

The strong coupling of cavity-confined photons and molecular electrons leads to the formation of hybrid light-matter states called cavity polaritons. While several groups have assessed the role of cavity polariton formation in important molecular photophysical processes, it remains unclear what resonator structures optimize control over ultrafast molecular dynamics and intermolecular interactions. In this talk, I will present results from our studies of cavity polariton formation and properties in multi-mode Fabry-Perot resonators loaded with porphyrin-based chromophores. For the first part of the presentation, I will discuss how changes in the structure of different multi-layer, multi-mode resonators affect the ultrafast radiative relaxation of copper (II) tetraphenylporphyrin. We show cavity polariton formation in the presence of strong, non-Condon vibronic coupling leads to the appearance of Lorentzian peaks in the photoluminescence spectra emitted by these samples. Using simple models, we show these features correspond to Herzberg-Teller (HT) polaritons, which possess deterministic characteristics consistent with our experimental data. In addition, we show how high-Q multimode cavities enhance coherent light emission from HT polaritons. For the second part of the talk, I will discuss our design, fabrication, and characterization of multi-layer, multi-mode Fabry-Perot resonators loaded with distinct porphyrin species. We show the near degeneracy of the electronic resonances of specific porphyrin pairs leads to the appearance of a middle polariton whose photonic content remains below 5%.