  We report the generation of multimode solitons in step-index fiber. The
solitons are superpositions of 5-10 temporally-aligned transverse modes, they
exhibit speckled beam profiles, and the spatio-spectral variation across the
soliton can be complex. Greater understanding of multimode solitons should
create a foundation for further research into complex multimode nonlinear
phenomena in step-index fibers. With energies of tens of nanojoules and
durations around 100 fs, the multimode solitons are speckled fields with peak
powers that can exceeed 300 kW, parameters which may be valuable in
applications.
