Discrimination of resonant and nonresonant contributions to n/sub 2/ in Cr and Nd doped crystals

E. V. Zharikov, S P Nasel'skiĭ, A. I. Riabov +1 more

S.M. Lima, T. Catunda

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.

K. Pattser

S.M. Lima, T. Catiinda

This work intends to distinguish resonant and nonresonant contributions to the nonlinear refractive index in ion doped solids using a two-color nonlinear technique. In this experiment, the alexandrite metastable excited state (/sup 2/E) is populated via the /sup 4/T/sub 2/ absorption band using a 514 nm pump beam (Ar/sup +/ laser), while the refractive index change is probed by a tunable dye laser, in resonance with the R lines (from ground to metastable transition at /spl lambda/ /spl sim/ 680 nm). The absorption spectrum with the two characteristic R lines is also shown just for comparison of the spectra. Observations reveal that an absorption saturation signal follows the linear absorption spectrum.

Bryan M. van der Ende

Karl K. Rebane