Observation of Multimode Solitons in Few-Mode Fiber
  We experimentally isolate and directly observe multimode solitons in few-mode graded-index fiber. By varying the input energy and modal composition of the launched pulse, we observe a continuous variation of multimode solitons with different spatiotemporal properties. They exhibit an energy-volume relation that is distinct from those of single-mode and fully spatiotemporal solitons. 
Zimu Zhu, Logan G. Wright, Demetrios N. Christodoulides, and Frank W.   Wise
physics.optics