Domination of ‘neck’ instability over ‘snake’ one in type II second harmonic generation

Abstract

We investigate modulational instability (MI) of 1-dimensional three-wave parametric solitons in presence of normal group velocity dispersion. In particular, we show that the ‘snake’ instability is strongly suppressed by the ‘neck’ one. This result is in a sharp contrast with previously studied MI in Kerr and type I quadratic media.