Abstract
In the realm of spatial information transmission in multimode fiber (MMF), the MMF-based endoscopes and information encryption technologies have garnered considerable attention. However, existing designs are limited to establishing a single connection between one input node and one output node, thus constraining the capacity and application scenarios of MMF spatial information transmission. Here, we demonstrate a new concept of MMF-based physical networking for spatial information transmission, and develop a physical model and implementation method for establishing multi-node networking with various topological structures via cascading MMFs.We experimentally verify the feasibility of parallel transmission of spatial information at multiple nodes in an exemplary three-node MMF network with chain topology, showcasing its capability in transmitting color images through "node multiplexing" with significantly enhanced communication security through long-distance reprogrammable optical encryption. Designing MMF networks based on different node quantities and topological structures can significantly expand the scenarios for MMF spatial information transmission, providing valuable paradigms for various applications such as minimally invasive panoramic endoscopy, low-cost distributed sensing, and scaling optical reservoir computing.