STATIONARY WALKING SOLITONS IN BULK QUADRATIC NONLINEAR MEDIA

We study the mutual trapping of fundamental and second-harmonic light beams propagating in bulk quadratic nonlinear media in the presence of Poynting vector beam walk-off. We show numerically the existence of a two-parameter family of (2 + 1)-dimensional stationary, spatial walki ng solitons. We have found that the solitons exist at various values o f material parameters with different wave intensities and soliton velo cities. We discuss the differences between (2 + 1) and (1 + 1)-dimensi onal walking solitons and between walking and non-walking solitons.