Numerical simulation activities aim at supporting the experiments on High-order Harmonic Generation (HHG), carried out by the Attophysics Group on the AttoLab laser facility. To this end, we develop numerical tools describing the non-linear response of a dilute medium to a strong laser field, on the two spatio-temporal scales of the problem: the microscopic scale, accounting for the interaction of a single atom with the local field, and the macroscopic one, describing the interaction between the laser beam and the target. The microscopic response, i.e. the dipole, is given by the solution of the time-dependent Schrödinger equation, while the macroscopic response is calculated using the wave equation, with the microscopic dipole as a source term.
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Microscopic response |
Macroscopic response |