2-DIMENSIONAL SOLITONS WITH 2ND-ORDER NONLINEARITIES

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