Thirring solitons in the presence of dispersion

The effect of dispersion or diffraction on zero-velocity solitons in 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/diffraction are shown numerically to be separated by a finite gap from three isolated soliton branches.Inside the gap, there is an infinity of multisoliton branches.Thus, the Thirring solitons are structurally unstable.In another parameter region (far from the Thirring limit), solitons exist everywhere.