title: Discrimination of resonant and nonresonant contributions to the nonlinear refraction spectroscopy of ion-doped solids.
abstract: Nonlinear refraction spectroscopy measurements were performed in resonance with absorption lines in Nd3+ and Cr3+ doped crystals. The observed line shapes can be explained by the interference of resonant and nonresonant contributions to the nonlinear refractive index. These effects were fully discriminated using a pump and probe configuration, in which a dispersive line shape was observed on the top of a plateau that was attributed to the polarizability difference between excited and ground states (Deltaalpha). A theoretical model was used to obtain Deltaalpha from the experimental data, and the results are in agreement with several previous experiments. Slow and fast light propagation are also discussed.
authors.affiliation: Universidade Estadual de Mato Grosso do Sul, 79420-970, Dourados, MS, Brazil.
authors.forename: S M
authors.initials: SM
authors.lastname: Lima
authors.forename: T
authors.initials: T
authors.lastname: Catunda