Abstract

We have studied diffraction effects on soliton formation using the semiclassical model of stimulated Raman scattering. We generate the soliton by placing a phase shift on the weak input Stokes field, and we study three-dimensional propagation effects in this system. Diffraction plays an unexpected role in enhancing the on-axis intensity of the Stokes field. The laser soliton is found to revert to its original on-axis intensity for Fresnel numbers around 10, and, at the same time, the on-axis Stokes field increases. This unusual phenomenon is accompanied by a narrowing of the Stokes and laser fields by a factor of five. These results will be explained, and further analysis will be presented.

© 1990 Optical Society of America