Abstract

It was predicted serevai years ago that the balance between diffraction and self-focusing in a Kerr type nonlinear medium leads to the propagation of a spatially stable wave under suitable initial conditions (1). These waves named spatial or geometrical solitons have already been observed in liquids, gases, and glasses (2-4), and require twodimensional propagation. On the other hand it has been theoretically pointed out (5) that it is possible for a strong pump beam to induce the trapping of a probe wave superimposed on the pump by means of cross phase modulation. However this approach neglects the fact that inevitably a cylindrical beam breaks up under chaotic self-focusing in threedimensional propagation.

© 1990 Optical Society of America