Two‐Photon Absorption by Envelope–Hole Coupled Exciton States in Cubic ZnSe. II. Polarization Dependence in the Case of Degenerate Valence Bands

The general angular dependence of two‐photon absorption for elliptical polarization is given in terms of complex polarization vectors in the case of cubic and spherical symmetry. The two‐photon transition probability for p‐like envelope–hole coupled exciton states is treated within an extended two‐band model which, for the case of degenerate valence bands, includes Hd‐term contributions of the exciton Hamiltonian. By use of the effective Bohr radii, resulting from the envelope–hole coupled exciton wave functions, the experimental polarization ratios yield good quantitative agreement with the values predicted theoretically.