A Comment on Non-Linear Depolarization Effects under the Giant Two-Photon Excitation of Excitonic Molecules in CuCl

Abstract

Photo-induced depolarization effect of linearly polarized beam in the giant two-photon absorption (GTA) band of excitonic molecules was examined in CuCl with the use of non-linear ellipsometry. After the careful elimination of the instrumental optical anisotropy, no depolarization was observed under the excitation of 1 MW/cm 2 . The stability of the linearly polarized state was also studied by measuring the polarization character for a slightly elliptical beam and a partially polarized beam. Growth of the depolarization was found in both cases and thus the linear polarization is concluded to be an unstable state in the GTA resonance.