Localized Probe of Molecular Interaction under Strong Light-Matter Coupling

Area of Science:

• Quantum optics
• Physical chemistry
• Materials science

Background:

• Strong light-matter coupling yields hybrid polariton states, impacting molecular dynamics and reactivity.
• Polaritonic signatures are evident in spectra, but their effect on molecular-scale interactions is not fully understood.

Purpose of the Study:

• To investigate whether molecular-scale interactions are altered under strong light-matter coupling.
• To probe the localized environment of strongly coupled systems using electronic energy transfer (EET).

Main Methods:

• Utilized femtosecond transient absorption spectroscopy.
• Introduced a probe molecule to measure EET rates within a Fabry-Pérot cavity.
• Measured EET between the probe and strongly coupled molecules.

Main Results:

• Observed no change in the EET rate between the probe and coupled molecules.
• EET rates remained constant despite significant spectral modifications under strong coupling.
• Demonstrated that near-field interactions governing molecular energy transfer are largely unaffected.

Conclusions:

• Local molecular interactions are preserved even under strong coupling conditions.
• Photophysics in polaritonic systems often reflect the behavior of uncoupled molecules.
• The developed EET approach is a versatile tool for analyzing local interactions in polaritonic materials.