  We demonstrate an efficient switching between strong and weak exciton-photon
coupling regimes in microcavity-embedded asymmetric double quantum wells,
controlled by an applied electric field. We show that a fine tuning of the
electric field leads to drastic changes in the polariton properties, with the
polariton ground state being red-shifted by a few meV and having acquired
prominent features of a spatially indirect dipolar exciton. We study the
properties of dipolar exciton polaritons, called dipolaritons, on a microscopic
level and show that, unlike recent findings, they are not dark polaritons but,
owing to the finite size of the excition, are mixed states with comparable
contribution of the cavity photon, bright direct, and long-living indirect
exciton modes.
