Abstract

There is a current interest in soliton formation and propagation sustained by pure parametric effects in quadratic media. Spatial trapping in the form of bright solitons has been demonstrated in second-harmonic generation.¹ The parametric amplification processes of the conservative type (i.e., in transparent cavityless media) support also topological solitons such as dark solitary waves or domain walls. However these turn out to be intrinsically unstable as a result of modulational instability of the background.² Conversely, we show here that stable topological parametric solitons do exist in the dissipative case. In particular, in a degenerate doubly resonant parametric oscillator (DOPO), one-dimensional solitons originate from the interplay of diffraction (or dispersion) and the phase-sensitive nature of the parametric process. Hence, they do not require any equivalent cubic nonlinearity, unlike the case of a singly resonant DOPO with filtering.³ We adopt path-averaged equations including diffraction to describe the DOPO dynamics⁴.

© 1997 Optical Society of America