Modulation instability of ultrashort pulses in quadratic nonlinear media beyond the slowly varying envelope approximation

摘要

We report a modulational instability (MI) analysis of a mathematical model appropriate for ultrashort pulses in cascaded-quadratic-cubic nonlinear media beyond the so-called slowly varying envelope approximation. The study shows the possibility of controlling the generation of MI and formation of solitons in a cascaded-quadratic-cubic medium in the few-cycle regimes.