Recent progress in wavefront shaping has enabled control of light propagation inside linear media to focus and image through scattering objects. In particular, light propagation in multimode fibres comprises complex intermodal interactions and rich spatiotemporal dynamics. Control of physical phenomena in multimode fibres and its applications are in their infancy, opening opportunities to take advantage of complex nonlinear modal dynamics. Here, we demonstrate a wavefront shaping approach for controlling nonlinear phenomena in multimode fibres. Using a spatial light modulator at the fibre input, real-time spectral feedback and a genetic algorithm optimization, we control a highly nonlinear multimode stimulated Raman scattering cascade and its interplay with four-wave mixing via a flexible implicit control on the superposition of modes coupled into the fibre. We show versatile spectrum manipulations including shifts, suppression, and enhancement of Stokes and anti-Stokes peaks. These demonstrations illustrate the power of wavefront shaping to control and optimize nonlinear wave propagation.

波前整形技术的最新进展已使控制线性介质内部的光传播得以通过散射物体聚焦和成像。特别是，多模光纤中的光传播包括复杂的联运相互作用和丰富的时空动力学。多模光纤中物理现象的控制及其应用还处于起步阶段，这为利用复杂的非线性模态动力学提供了机会。在这里，我们演示了一种用于控制多模光纤中非线性现象的波阵面整形方法。在光纤输入端使用空间光调制器，实时光谱反馈和遗传算法优化，我们通过耦合到光纤中的模叠加的灵活隐式控制，来控制高度非线性的多模激发拉曼散射级联及其与四波混频的相互作用。我们展示了多种频谱操作，包括Stokes和Anti-Stokes峰值的偏移，抑制和增强。这些演示说明了波前整形对控制和优化非线性波传播的作用。