  We develop a new model of laser-matter interaction based on Optical Bloch
Equations, which includes photo-ionization, impact ionization, and various
relaxation processes typical of dielectric materials. This approach is able to
describe the temporal evolution of the electron dynamics in the conduction band
driven by few-cycle laser pulses of any wavelength. Moreover, the nonlinear
polarization response of both centrosymmetric and non-centrosymmetric materials
can be described while ensuring the proper selection rules for the harmonics
emission.
