Determination of Ni2+ concentration dependence of the nonlinear refractive index of BaLiF3:Ni2+ crystal by the resonant Z-Scan method

The resonant Z-Scan technique was used to measure the real and imaginary parts of the nonlinear refractive index of a new material, the Ni2+ doped BaLiF3 crystal. We used four different dopant concentrations and could determine the concentration dependence behavior of the nonlinear macroscopic parameters. The microscopic (local) nonlinear parameters per ion were determined and for low Ni2+ concentrations they are constant. The excited state absorption cross section was estimated in first-order and it has the same magnitude of the ground state absorption cross section. (C) 1998 Elsevier Science Ltd. All rights reserved.