Transient polarization state of four-wave-mixing signals: identification of higher-order correlations

Summary form only given. Recently, four-wave-mixing (FWM) experiments on semiconductors have been extended by time-resolved analysis of the polarization state of the diffracted pulses. It was found that the seemingly unpolarized fraction of the signal observed in time-integrated data is caused by averaging over a pulse having a perfect polarization state which, however, changes in time. Since in certain configurations the occurrence of a time dependent polarization is due to processes of higher than third order in the driving fields, the measurement of its intensity dependence allows for a sensitive test of theories which include higher-order correlations as is presented below. The experiments are conducted on a ZnSe/ZnMgSSe single quantum wells.