Predicting the linear optical response of J-aggregate microcavity exciton-polariton devices

We demonstrate that linear dispersion theory accurately predicts the linear optical response of strongly coupled microcavity exciton-polariton devices containing thin films of J aggregates of the cyanine dye [5,6-dichloro-2-[3-[5,6-dichloro-1-ethyl-3-(3-sulfopropyl)-2(3H)-benzimi dazolidene]-1-propenyl]-1-ethyl-3-(3-sulfopropyl) benzimidazolium hydroxide, inner salt, sodium salt] (TDBC) when a spectrally resolved complex index of refraction derived by model-free quasi-Kramers-Kronig regression is used for the J-aggregate thin film. We show that the Rabi splitting can be finely tuned through the J-aggregate film thickness, and we estimate that the minimum linewidth of lower branch exciton polaritons at room temperature in TDBC J-aggregate-based structures is 8.4 meV.