Transverse nonlinear front (or domain wall) propagation in degenerate optical parametric oscillators, for positive detunings and in the presence of walk-off, is investigated. A quintic Ginzburg–Landau equation including diffraction and walk-off is derived close to subcritical bifurcation. A new threshold is found below the linear one, where nonlinear front propagation dominates the dynamics. The velocity and the wave number of these fronts are determined. Nonlinear absolute and convective instabilities are shown to strongly alter the hysteresis cycle, which completely vanishes when the walk-off exceeds some critical value.
© 2000 Optical Society of America
(190.0190) Nonlinear optics : Nonlinear optics
(190.4420) Nonlinear optics : Nonlinear optics, transverse effects in
(190.4970) Nonlinear optics : Parametric oscillators and amplifiers
(190.5530) Nonlinear optics : Pulse propagation and temporal solitons
Majid Taki, Najib Ouarzazi, Hélène Ward, and Pierre Glorieux, "Nonlinear front propagation in optical parametric oscillators," J. Opt. Soc. Am. B 17, 997-1003 (2000)