Compensation of nonlinear self-focusing in high-power lasers

We report on experimental results and the numerical modeling of the compensation of nonlinear self-focusing effects occurring in a high-power Nd:glass laser system at intensities above 1 GW/cm/sup 2/. A GaAs wafer with a negative nonlinear refractive index was used for the cancellation of the accumulated phase difference along the beam direction in a nonlinear medium (B integral). A numerical model is developed to calculate the behavior of the experimental setup.