Spatiotemporal Mode-Locking is Generalized Mode-Locking

In mode-locking, light in a resonator self-organizes into a nonlinear attractor, the dissipative soliton, often with rich dynamics. Mode-locking has enabled a myriad of applications through ultrashort duration pulses, high peak intensity, and broad frequency comb spectra. Virtually all work on the topic has considered light propagating on only one dimension, as in single-mode fiber. We recently demonstrated spatiotemporal mode-locking [1], the self-organized locking of many spatial and longitudinal modes into coherent pulses, i.e., three-dimensional mode-locking. Adding new dimensions to light’s self-organization gives rise to new ways to control the light field. Here, we outline a general theory of spatiotemporal mode-locking, showing it to be a generalization of mode-locking, and present new experimental measurements of qualitatively new mode-locked states, comprising nearly 30 million locked modes. Additionally, we predict numerous other novel forms of mode-locking, and phenomena, such as spatiotemporal dissipative soliton competition.
1. L.G. Wright, D.N. Christodoulides, & F.W. Wise (2017). Spatiotemporal mode-locking in multimode fiber lasers. Science, 358(6359), 94-97.