Abstract

Spatial optical solitons are self-trapped optical beams which propagate without changing their spatial shape because of the competing effects of diffraction and self-focusing in a nonlinear medium¹. Self-trapped beams are known to be unstable in bulk media, and to lead to catastrophic self-focusing. They are stable, however, when diffraction is limited to one spatial dimension, such as in planar optical waveguides. The spatial soliton is described by the non;linear Schroedinger equation, and it is completely analogous to the temporal soliton in optical fibers. Spatial solitons have recently been reported in multimode CS₂ waveguides² and single mode glass waveguides³. The nonlinear contribution to the refractive index, essential for the observation of these solitons, can also give rise to interaction forces between pairs of solitons. These forces have been studied theoretically⁴ and have been experimentally observed in the temporal domain⁵. Here we report the first experimental observation of interaction between spatial solitons.

© 1990 Optical Society of America