Observation of non-classical light in semiconductor microcavities
  Semiconductor microcavities are widely used to study collective interactions of cavity exciton-polaritons leading to their condensation phenomenon. Exciton-light interaction is highly enhanced in such structures due to the resonance enhancement of the electromagnetic field inside the high quality cavity. Considerably lower interest is concerned to exciton states non-resonant with the cavity mode for which the exciton-photon interaction is strongly reduced due to the existence of the cavity. We point out here that these states are responsible for non-classical light generation in semiconductor microcavities. 
Mikhail Lebedev, Andrey Parakhonsky, Andrey Demenev
cond-mat.mes-hall cond-mat.quant-gas physics.optics