5. Nonlinear Optics

Questions addressed: Description of pulse propagation in materials and media (air, water, cluster-gas)? Explanation and predictions for experiments on materials processing, environmental sciences and femto- chemistry in solutions? Analytical description beyond the variational approach?

We demonstrate that laser beam collapse in highly nonlinear media can be described, for a large number of experimental conditions, by the geometrical optics approximation within high accuracy. Taking into account this fact we succeed in constructing analytical solutions of the eikonal equation, which are exact on the beam axis and provide: i) a first-principles determination of the self-focusing position, thus replacing the widely used empirical Marburger formula, ii) a benchmark solution for numerical simulations, and iii) a tool for the experimental determination of the high-order nonlinear susceptibility. Successful comparison with several experiments is presented.

Methods: Renormalization group approach, variational approach, symmetry analysis

Publications: [73], [78] (see list of publications)