Two-dimensional solitons with second-order nonlinearities

We investigate the propagation of intense Gaussian beams in materials with quadratic nonlinearity. Excitation of (2 + 1) solitons is numerically predicted at finite phase mismatch and in the presence of linear walk-off between the fundamental and second-harmonic waves. The numerical results are interpreted in terms of the conserved quantities of the wave evolution, and the appropriate conditions for the experimental observation of the solitons are discussed.Peer ReviewedPostprint (published version