Application of the Green's function formalism to the interplay between avalanche and multiphoton ionization induced by optical pulses

A fundamental brick of light-matter interaction at large optical intensities is the generation of a plasma. The optically induced plasma in turn plays a fundamental role in determining the optical propagation. The plasma generation is a result of the interplay between multiphoton, tunnel, and avalanche ionization. Here we use the basic rate equations to discuss an analytical model for the interaction between these physical effects. After defining a nonlinear impulse response for the system, we describe how the interplay depends on the features of the optical pulses. Our approach strongly simplifies the modeling of the propagation of ultrashort pulses, paving the way to a much easier and faster interpretation of experimental observations, with potential impact on the broad fields of ultrafast light-matter interaction and laser micromachining.