Multi-frequency spatial solitons in Kerr media

Abstract

We investigate an expanded class of self-guided beams (or spatial solitons), which consist of two or more different optical frequencies, in Kerr media. We show both analytically and numerically that when the nonlinearity is focussing, these solitons are all very stable and may be excited by end-fire launching, while in defocussing media, they are all unstable and break into filaments on propagation. We also show that the variational method with simple trial functions, which is quite useful in describing single-frequency self-guided beams, does not give a satisfactory description of the interaction between two or more self-guided beams at different frequencies.