Fig. 5: Spatiotemporal soliton formed from an input 235 fs pulse.
From: Conditions for walk-off soliton generation in a multimode fiber

The soliton is composed by three axial modes, propagating over 120 m of graded-index (GRIN) fiber, for the optimal input energy of 2.5 nJ. (a) modes power, (b) modes spectra.