Enhancement of Rabi splitting in a microcavity with an embedded superlattice - art. no. 155302

We have observed a large coupling between the excitonic and photonic modes of an AlAs/AlGaAs microcavity filled with an 84 Angstrom /20 Angstrom GaAs/ AlGaAs superlattice. Reflectivity measurements on the coupled cavity-superl attice system in the presence of a moderate electric field yielded Rabi spl ittings of 8.5 meV at T =293 K and 9.5 meV at T=238 K. This splitting is al most 50% larger than that found in comparable microcavities with quantum we lls placed at the antinodes only. We explain the enhancement by the larger density of optical absorbers in the superlattice, combined with the quasi-t wo-dimensional binding energy gy of field-localized excitons.