Physics of highly multimode nonlinear optical systems

• Published in: Nature physics Vol. 18; no. 9; pp. 1018 - 1030
• Main Authors: Wright, Logan G., Wu, Fan O., Christodoulides, Demetrios N., Wise, Frank W.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01.09.2022; Nature Publishing Group
• Subjects: 639/624/1075/187; 639/624/400/385; Atomic; Classical and Continuum Physics; Complex Systems; Condensed Matter Physics; Fiber lasers; Laser cavities; Machine learning; Mathematical and Computational Physics; Molecular; Nonlinear optics; Nonlinear systems; Nonlinearity; Optical and Plasma Physics; Physics; Physics and Astronomy; Review Article; Solitary waves; Statistical mechanics; Theoretical; Wave physics; Wave propagation; Waveguides
• ISSN: 1745-2473; 1745-2481
• DOI: 10.1038/s41567-022-01691-z

Linear multimode optical systems have enabled clean experimental observations and the applications of numerous phenomena that continually extend the boundaries of wave physics. The infrastructure that has enabled these studies facilitates the study of an even richer world of nonlinear multimode optical systems. Multimode nonlinear optical physics is full of emergent phenomena, including robust spatial attractors, multimode wave instabilities, and conservative and dissipative multimode solitons. Many of these effects push the limits of existing theoretical techniques, demanding new insights and approaches that could emerge from other fields, such as statistical mechanics, physics-informed machine learning, network science and beyond. Here we provide an overview of recent investigations of wave propagation in highly multimode nonlinear systems, principally multimode fibre waveguides and laser cavities. These systems, with their multifaceted control, low cost, scalability and ultrahigh bandwidth, are ideal physical platforms for exploring—and ultimately applying—high-dimensional nonlinear physics, from orderly but elusive objects like spatiotemporal solitons to dynamical complexity itself, both near and far from equilibrium. Nonlinearities allow the large number of modes in a multimode fibre to interact and create emergent phenomena. This Review presents the breadth of the high-dimensional nonlinear physics that can be studied in this platform.