2-PHOTON ABSORPTION AND MAGNETOABSORPTION OF P-EXCITONS IN BETA-ZNP2

Electronic transitions in biaxial beta-ZnP2 are studied by two-photon absorption. The anisotropy of the crystal leads to a large energy spli tting of the P excitons. The energy shift of the P excitons and Landau transitions are observed in a magnetic field up to 6T. We present a t heory which describes the anisotropic P excitons in a magnetic field. The analysis of the experimental data allows the determination of the anisotropic dielectric constants and effective masses of the valence a nd conduction bands.