Control of Rabi-splitting energies of exciton polaritons in CuI microcavities
- 295 Downloads
We have investigated the active-layer-thickness dependence of exciton-photon interactions in CuI microcavities. The active layer thickness was changed from λ/2 to 2λ, where λ corresponds to an effective resonant wavelength of the lowest-lying exciton. In the CuI active layer, thermal strain removes the degeneracy of the heavy-hole (HH) and light-hole (LH) excitons at the Γ point. Angle-resolved reflectance spectra measured at 10 K demonstrate the strong coupling between the HH and LH excitons and cavity photon, resulting in the formation of three cavity-polariton branches: the lower, middle, and upper polariton branches. The energies of the three cavity-polariton modes as a function of incidence angle are reasonably explained using a phenomenological Hamiltonian to describe the exciton-photon strong coupling. It is found that the interaction energies of the cavity-polariton modes, the so-called vacuum Rabi-splitting energies, are systematically controlled from 29 (50) to 48 (84) meV for the LH (HH) exciton by changing the active layer thickness from λ/2 to 2λ. The active-layer-thickness dependence of the Rabi-splitting energies is semi-quantitatively explained by a simple model.
KeywordsTopical issue: Excitonic Processes in Condensed Matter, Nanostructured and Molecular Materials. Guest editors: Maria Antonietta Loi, Jasper Knoester and Paul H. M. van Loosdrecht
- 1.A.V. Kavokin, J.J. Baumberg, G. Malpuech, F.P. Laussy, Microcavities (Oxford University Press, Oxford, 2007)Google Scholar
- 17.M. Ueta, H. Kanzaki, K. Kobayashi, Y. Toyozawa, E. Hanamura, Excitonic Processes in Solids (Springer, New York, 1986), p. 116.Google Scholar
- 31.C.F. Klingshirn, Semiconductor Optics (Springer, Berlin, 2007), p. 73Google Scholar