Nonlinear polaritons in II–VI MQW heterostructures

The linear propagation of femtosecond pulses in the growth direction of excited II–VI semiconductor MQW heterostructures is studied by combining calculations of the nonlinear absorption of quantum wells from many-body theory with the transfer matrix method from classical electrodynamics. It is shown that the time-resolved transmission of the heterostructure is substantially modified in the presence of a nonvanishing quasi-equilibrium carrier density which is accompanied by characteristic changes of the optical absorption and refractive index.