Multimode solitons and soliton trains driven by space-time inputs to multimode fibers

Expanding nonlinear optics in optical fibers to multimode fibers has allowed for observing and learning about significantly more complex phenomena, while also enabling control over processes like beam self-cleaning, supercontinuum generation, and soliton formation. Implicit in all of these investigations is the eventual development along nonlinear propagation of high-dimensional fields that are structured in space and time. In our work we consider the same physical system, i.e. a graded-index multimode fiber, but with input fields that already have their own space-time structure. In doing so we gain a much more explicit control over the highly nonlinear interactions, and can observe new effects such as multimode domain wall locking and especially a new form of multimode solitons, and trains of such solitons. We will discuss the formation and properties of these new nonlinear optical structures and the implications.