Replacing independent single quantum wells inside a strongly-coupled
semiconductor microcavity with double quantum wells produces a special type of
polariton. Using asymmetric double quantum wells in devices processed into
mesas allows the alignment of the electron levels to be voltage-tuned. At the
resonant electronic tunnelling condition, we demonstrate that `oriented
polaritons' are formed, which possess greatly enhanced dipole moments. Since
the polariton-polariton scattering rate depends on this dipole moment, such
devices could reach polariton lasing, condensation and optical nonlinearities
at much lower threshold powers.Comment: 3 figure