Editorial: Advances and applications of optical wireless communication in next-generation networks

LEO constellations. The work addresses practical challenges such as cloud blockage, beam alignment, and atmospheric turbulence, offering a realistic design pathway for secure and highrate inter-satellite optical networks. Carrasco-Casado et al. [2] contribute essential hardware-level innovation through the development and environmental qualification of a compact dual-stage EDFA integrating a high-power amplifier and low-noise amplifier for CubeSat-based OWC missions. Their system, designed for the CubeSOTA payload, achieves a 2-W output in a 0.56-kg footprint and withstands vacuum, thermal cycling, and vibration conditions. This work directly supports the miniaturization and scalability required for future large-constellation optical networks. b) OWC for Vehicular and Smart-City Applications: Garai et al. [3] explores the integration of VLC into intelligent transportation systems through a tree-structured VLC VANET architecture using hierarchical optical codewords for node identification. Their design reduces collisions, improves routing efficiency, and adapts to mobility variations using dynamic attachment and QoS mechanisms. Through mobility-model-based simulations, the authors demonstrate improved scalability, latency, and throughput-highlighting VLC's viability for next-generation V2X communication where RF congestion and latency remain critical bottlenecks. c) Hybrid OWC Architectures and Multiplexing Technologies: Singh et al. [4] propose a hybrid optical communication system combining FSO and single-mode fiber, enhanced by orbital angular momentum (OAM) multiplexing. Supporting four 10-Gbps channels under heterogeneous atmospheric and fiber conditions, their system demonstrates strong resilience, including under fog and turbulence. By enabling multi-user access and flexible connectivity, the work advances scalable hybrid optical networks suited for last-mile delivery, urban backhaul, and emergency links. Chaudhary et al. [5] investigated a hybrid Mode-Division-Multiplexed MIMO Radio-over-FSO system operating at an 80-GHz mm-wave carrier. Their results confirm that 4×4 MIMO-MDM configurations significantly improve spectral efficiency and BER performance under both weak and strong atmospheric scintillation. The work highlights the relevance of RoFSO links for highcapacity 5G/6G backhaul, emergency communications, and satellite integration, especially in environments where RF-only solutions struggle with blockage or attenuation.Collectively, the contributions in this Special Issue demonstrate the breadth, maturity, and accelerating pace of research in Optical Wireless Communication. From secure inter-satellite relays to smart vehicular VLC networks, from OAM-multiplexed hybrid architectures to MDM-MIMO RoFSO platforms and space-qualified amplifiers, the featured works advance OWC technologies across theoretical, simulation, and experimental domains. As 6G envisions unified terrestrial-non-terrestrial networks, OWC stands out as a key enabler of ultra-high-capacity connectivity, secure channels, and resilient communication in challenging environments. We hope this collection inspires further interdisciplinary collaboration and accelerates the integration of OWC into real-world networks.We thank all authors, reviewers, and contributors for their valuable efforts and look forward to future advancements in this rapidly evolving field.