Talk of Prof. Young-Chai Ko






Young-Chai Ko



Free Space Optical Communications: Enabling High-Speed Connectivity from Space to Servers

Abstract

Free Space Optical (FSO) communication is emerging as a key enabler of next-generation wireless networks. Utilizing laser beams for data transmission through the atmosphere or space, FSO systems offer significant advantages such as ultra-high data rates, extremely low latency, license-free spectrum use, and energy efficiency. These attributes make FSO highly attractive for various applications, ranging from space-based networks to terrestrial infrastructure. In particular, FSO is increasingly being adopted in inter-satellite links (ISLs), where the demand for high-capacity, secure, and low-latency communication between satellites is rapidly growing. Beyond space applications, FSO is also a compelling candidate for terrestrial cellular backhaul, where fiber deployment may be costly or infeasible. Additionally, with the growing demand for high-speed, short-range data transmission in high-performance computing (HPC) environments, FSO provides a promising alternative to traditional wired interconnects between servers. This keynote will begin by introducing the fundamental principles of FSO communication, followed by a detailed discussion of key technical challenges, including atmospheric channel modeling, beam pointing and alignment, and robust signal acquisition and tracking. State-of-the-art solutions to these challenges will be explored, highlighting recent research and technological advancements. The presentation will also examine the practical integration of FSO systems into current and future networks, illustrating how FSO can complement or enhance existing RF-based systems. Use cases will be presented to demonstrate the versatility of FSO technology, including its application in satellite constellations, mobile fronthaul/backhaul, and data center interconnects. The talk will conclude with insights into ongoing research directions and the future potential of FSO in enabling global, ultra-high-speed connectivity.




Biography

Professor Young-Chai Ko is a faculty member in the School of Electrical and Computer Engineering at Korea University, where he has been serving since March 2004. He has held numerous leadership roles throughout his career, both within the university and across Korea’s research and academic communities. From 2018 to 2020, he served as Associate Dean of the College of Engineering at Korea University, contributing to academic administration and strategic planning. From August 2022 to July 2024, he served as Program Director in the Division of Information and Convergence Technology at the National Research Foundation (NRF) of Korea, where he was responsible for guiding national R&D programs in next-generation ICT. Since May 2021, he has been the Director of the Radio Research Center for the Next Generation Satellite Communications (RRC-SatCom), a long-term national project funded by the Institute for Information & Communications Technology Planning & Evaluation (IITP), focused on advancing satellite communication technologies. He currently serves as Vice President of The Korean Institute of Communications and Information Sciences (KICS), an elected position for the 2023–2025 term, where he plays a leading role in promoting academic collaboration and technological innovation in Korea. In recognition of his international standing in the field, he has also been appointed as an Associate Editor for the IEEE Transactions on Vehicular Technology (TVT), beginning in August 2025. His primary research interests include channel modeling, free-space optical (FSO) communications, high-performance computing (HPC) wireless interconnects, and satellite communications. Through his academic and professional work, Professor Ko continues to contribute significantly to the advancement of next-generation wireless and satellite communication systems.