THz electromagnetic wave radiation from semiconductor microcavities in nonperturbative regime

Coherent coupling between the excitons in the quantum well and the cavity-m ode photons in high-Q semiconductor microcavities brings about the formatio n of cavity-polariton modes. In such a system, periodic energy exchange bet ween the excitons and photons, instead of the monotonical decay of the exci ton population following the Fermi's golden rule, can be triggered by the s imultaneous excitation of the two polariton modes by a short laser pulse. T he periodic energy exchange results in the nutation of the exciton populati on. We demonstrate, in this paper, that THz-electromagnetic waves are radia ted from the oscillation of the exciton population in high-Q microcavities where the inversion symmetry of the exciton is broken by a static electric field. (C) 1999 Elsevier Science B.V. All rights reserved.