Spatial channel network (SCN): implementation and feasibility demonstrations of modular spatial cross-connects using three types of packaged 19-core-fiber-based optical switches

We report the implementation and experimental feasibility demonstration of modular spatial cross-connects (SXCs) for spatial channel networks (SCNs) based on route-and-select architectures using packaged 19-core-fiber (19-CF)-based optical switches. The SXCs employ hermetically sealed core selective switches (CSSs), core selectors (CSs), and core port selectors (CPSs) integrated into a compact 1U rack-mount chassis with software-based polarity and core-arrangement management, enabling any-core-access, nondirectional, and contentionless spatial-channel (SCh) routing. We experimentally demonstrate hierarchical establishment, routing, and protection of SChs and wavelength channels; core-contention-free SCh establishment using CPS-based add/drop sections; and inter-domain SCh establishment and restoration in a heterogeneous 4-core-fiber (4-CF)/16-core-fiber (16-CF) SCN. The heterogeneous SCN is interconnected via a spatial gateway constructed using 19-CF CSSs and 4-C/19-C converters, with loss compensation provided by cladding-pumped 19-CF erbium-doped fiber amplifiers (EDFAs) and first-in-first-out-less core-pumped 4-CF EDFAs. Experimental results show low insertion loss, low inter-core crosstalk, a negligible optical-signal-to-noise-ratio penalty, and successful fault protection and restoration, demonstrating the practical feasibility and scalability of CSS-based modular SXCs for future large-scale SCNs.