Effect of the pumping intensity on the resonant secondary emission spectra of optically aligned hot excitons in ZnTe crystals

The spectra for cleaved and mechanically polished surfaces of ZnTe single crystals at 90K were investigated. The results of polarization measurements show the dependence of the linear polarization degree (LPD) rho of multiphonon lines on the pumping intensity, with the polarization degree of the 6 LO-phonon line increasing from 0.10 to 0.35 with excitation level from 10 exp 19 to 3 x 10 exp 20 photons cm exp 2 s exp 1 . Also the rise of the pumping intensity from 2 x 10 exp 20 to 2 x 10 exp 21 photons cm exp 2 s exp 1 results in an increase of LPD for all multiphonon lines. The LPD increase with excitation intensity is connected with the decrease of the exciton elastic scattering probability.--J.J.P.