Two-photon selective population of energy valleys in PbTe and jumps of the recombination-radiation polarization direction
Areshev I.P., Danyshevskii A.M., Kochegarov S.F., Subashiev V.K.
We report observation of linearly polarized stimulated recombination radiation (RR) from a lead telluride crystal following two-photon pumping with linearly polarized radiation of wavelength 10.6 μ. The direction of the RR experiences a jump of ~90° when the direction of the polarization of the pump radiation (PR) (from —8 to +8°) in the crystal plane (100) undergoes a small change relative to the [010] direction. When the direction of the PR polarization is varied in the range —45-0°, the degree of polarization of the RR changes from 0.85 to 0.15. These facts are attributed to the onset of selective population of the energy valleys.