2D semiclassical model for high harmonic generation from gas

The electron behavior in laser field is described in detail. Based on the 1 D semiclassical model, a 2D semiclassical model is proposed analytically us ing 3D DC-tunneling ionization theory. Lots of harmonic features are explai ned by this model, including the analytical demonstration of the maximum el ectron energy 3.17 U-p. Finally, some experimental phenomena such as the in crease of the cutoff harmonic energy with the decrease of pulse duration an d the "anomalous" fluctuations in the cutoff region are explained by this m odel.