Polarization control of the nonlinear emission of semiconductor microcavities -: art. no. 077402

The degree of circular polarization (p) of the nonlinear emission in semiconductor microcavities is controlled by changing the exciton-cavity detuning. The polariton relaxation towards Ksimilar to0 cavitylike states is governed by final-state stimulated scattering. The helicity of the emission is selected due to the lifting of the degeneracy of the +/-1 spin levels at Ksimilar to0. At short times after a pulsed excitation p reaches very large values, either positive or negative, as a result of stimulated scattering to the spin level of lowest energy (+1/-1 spin for positive/negative detuning).