The effect of dispersion on existence of solitons is studied for the generalized massive Thirring model describing a nonlinear optical fiber with grating or parallel-coupled planar waveguides with misaligned axes. The Thirring solitons existing at zero dispersion are shown numerically to be separated by a finite dispersion gap from three isolated soliton branches. Inside the gap, there is an infinity of multi-soliton branches, which are presumably dynamically unstable. Thus, the Thirring solitons are structurally unstable. In another parameter region (far from the Thirring limit), solitons exist everywhere.
Additional information: Preprint of a paper later published by the American Physical Society (1998), Physical Review Letters, 80 (19), pp.4169-4172, ISSN 0031-9007
- Thirring solitons, dispersion, nonlinear optical fiber, generalized massive Thirring model, parallel-coupled planar waveguides