Abstract
We use femtosecond transient absorption spectroscopy to study the temporal dynamics of strongly coupled exciton-plasmon polaritons in metasurfaces of aluminum nanoantennas coated with J-aggregate molecules. Compared with the thermal nonlinearities of aluminum nanoantennas, the exciton-plasmon hybridization introduces strong ultrafast nonlinearities in the composite metasurfaces. Within femtoseconds after the pump excitation, the plasmonic resonance is broadened and shifted, showcasing its high sensitivity to excited-state modification of the molecular surroundings. In addition, we observe temporal oscillations due to the deep subangstrom acoustic breathing modes of the nanoantennas in both bare and hybrid metasurfaces. Finally, unlike the dynamics of hybrid states in optical microcavities, here, ground-state bleaching is observed with a significantly longer relaxation time at the upper polariton band.
| Original language | English |
|---|---|
| Pages (from-to) | 7675-7683 |
| Number of pages | 9 |
| Journal | Nano Letters |
| Volume | 17 |
| Issue number | 12 |
| DOIs | |
| State | Published - 13 Dec 2017 |
Keywords
- Plasmonics
- aluminum nanoantennas
- organic polaritons
- strong coupling
- temporal dynamics
- ultrafast photonics
All Science Journal Classification (ASJC) codes
- Bioengineering
- Chemistry(all)
- Materials Science(all)
- Condensed Matter Physics
- Mechanical Engineering