Generation of Anti-Stokes Fluorescence in a Strongly Coupled Organic Semiconductor Microcavity

TL;DR

This paper demonstrates anti-Stokes fluorescence generation in strongly coupled organic microcavities, revealing a process involving thermal energy absorption and polariton dynamics, with potential implications for energy conversion and photonics.

Contribution

It introduces a novel mechanism for anti-Stokes fluorescence involving polariton states in organic microcavities, highlighting the role of cavity suppression of Stokes emission.

Findings

Observation of polariton emission along the lower polariton branch.

Evidence of thermal energy absorption from vibrationally excited molecules.

Suppression of Stokes-shifted fluorescence by the cavity.

Abstract

We explore the generation of anti-Stokes fluorescence from strongly coupled organic dye microcavities following resonant ground-state excitation. We observe polariton emission along the lower polariton branch, with our results indicating that this process involves a return to the exciton reservoir and the absorption of thermal energy from molecules in a vibrationally excited ground-state. We speculate that the generation of a population of "hot" polaritons is enhanced by the fact that the cavity supresses the emission of Stokes-shifted fluorescence, as it is located energetically below the cut-off frequency of the cavity.