Abstract
With a high quality strain free ZnSe sample, the biexciton states are studied at 10K. The delay time dependences, spectral responses of the two-pulse four- wave mixing signal are examined in two polarization configurations. In orthogonal polarization configuration, biexciton two-photon resonance is clearly observed. The observed binding energy is 4 meV which is also confirmed by the nonlinear emission spectra associated with the biexciton destruction. The polarization dependences of the four-wave mixing signal are found to be a powerful tool to examine the biexciton contribution near the exciton resonance.