Triple excitonic mixing associated with recoupling of a Stark-localized state in coupled quantum wells confined by superlattices

The triple-coupling phenomena of excitonic states were found in the electroabsorption characteristics of GaAs asymmetric coupled quantum wells sandwiched by AlAs-GaAs superlattices. The peculiar optical characteristics can be explained by taking account of the effective recoupling of a Stark-localized state formed in the superlattice confinement region with the coupled states in the quantum wells. The interpretation, furthermore, was supported by a numerical calculation of the eigenenergies of the system in an electric field. numerical calculation of the eigenenergies of the system in an electric field.