Exciton-plasmon polaritons in WSe2/Au heterostructures are imaged, which show a strong coupling between excitons in WSe2 and surface plasmons on gold.
Significance and Impact
Due to the strong exciton-plasmon coupling, polaritons have shown a record-high spatial confinement and a strong field enhancement. These highly-confined and strongly-enhanced polaritons are desirable for future applications in nanophotonic sensing and signal processing.
- Interference fringes from exciton-plasmon polaritons were imaged at various excitation energies.
- The dispersion diagram of the polaritons demonstrate a strong exciton-plasmon coupling.
- The polariton wavelength can be controlled by varying the WSe2 thickness. It can reach as low as 210 nm, 4 times smaller than the photon wavelength.
R. B. Iyer, Y. Luan, R. Shinar, J. Shinar, Z. Fei, “Nano-optical imaging of exciton-plasmon polaritons in WSe2/Au heterostructures,” Nanoscale 14, 15663 (2022). https://doi.org/10.1039/D2NR04321A