A quantitative-accurate S-Matrix model for the description High-Order Harmonic Generation

We present an S-matrix based model that provides a quantitative description over a wide range of realistic situations. The generation of radiation of very high harmonic frequencies is a relevant feature arising in the interaction of intense lasers with matter. Besides its theoretical interest as a paradigm of a non-perturbative phenomenon, it also conveys a number of technological applications (generation of coherent high frequency radiation, attosecond pulse generation, etc.).