Tutorial 2 - High-Capacity Optical Communications Using Space-Division Multiplexing

Space-division multiplexing (SDM) leverages the multiplicity of spatial channels to break the capacity limits of conventional single-mode optical communications. This tutorial explores the implementation of SDM in fiber-optic systems using few-mode fibers (FMFs) and multimode fibers (MMFs), with a specific focus on the utilization of Linearly Polarized (LP) modes and Orbital Angular Momentum (OAM) modes as independent data carriers. We examine the critical challenges, opportunities, and emerging applications of SDM, particularly the role of multiple-input and multiple-output (MIMO) equalization as an electronic solution to mitigate inherent mode crosstalk. To bring the computational complexity of MIMO processing to practical levels, we discuss essential optical strategies, including differential modal group delay (DMGD) management, the transition to strong mode coupling regimes, and the use of multicore fibers (MCFs). Furthermore, the tutorial addresses system-level bottlenecks involving both passive components, such as spatial (de)multiplexers, and active devices like few-mode/multicore optical amplifiers. Finally, we review the long-term prospects for SDM in scaling the next generation of high-capacity optical transmission and transparent networking.

  • Corresponding Author Information
    Yang Yue, Xi'an Jiaotong University, China
    Yang Yue is a Professor at the School of Information and Communications Engineering, Xi'an Jiaotong University. He earned his Ph.D. from the University of Southern California (2012) following degrees from Nankai University. Dr. Yue’s current research interest is intelligent photonics, including optical communications, optical perception, and optical chip. He has published >300 journal papers (including Science) and conference proceedings with >14,000 citations, two books (Elsevier, Springer Nature), eight edited books, two book chapters, >50 issued patents (including 30 U.S. patents and 6 European patents), >200 invited presentations (including 1 tutorial, >30 plenary and >100 keynote talks). Dr. Yue is a Fellow of Optica and SPIE. He is an Associate Editor for IEEE Access and Frontiers in Physics, Editor Board Member for four other scientific journals, Guest Editor for >10 journal special issues. He also served as Chair for >100 international conferences, Reviewer for >80 prestigious journals.

  • Speaker 1: Jian Zhao, Tianjin University, China
  • Title: Space-Division Multiplexing via LP Modes: From Fiber Physics to High-Capacity Systems
    Jian Zhao received the B.Eng. degree in optoelectrical engineering from Tianjin University, Tianjin, China, in 2003, the M.S. degree in optics from Nankai University, in 2006, and the Ph.D. degree in electronics and information engineering from The Hong Kong Polytechnic University, in 2010. From 2016 to 2017, he was a visiting scholar of the CREOL, The College of Optics and Photonics, University of Central Florida. He is currently an Associate Professor with the School of Precision Instruments and Optoelectronics Engineering, Tianjin University. He has authored or coauthored more than 100 articles in peer-reviewed journals and leading international conferences. His current research interests include space division multiplexing, coherent optical fiber communications, optical artificial intelligence, optical computing and optical AI chip. He was also the PI of the National Key Research and Development Program of China. He has been selected for Tianjin's "131" Innovative Talent Project and Jiangsu Province Double Innovation Talent.

  • Speaker 2: Yang Yue, Xi'an Jiaotong University, China
  • Title: Orbital Angular Momentum-Enabled Optical Communications and Networks
    Yang Yue is a Professor at the School of Information and Communications Engineering, Xi'an Jiaotong University. He earned his Ph.D. from the University of Southern California (2012) following degrees from Nankai University. Dr. Yue’s current research interest is intelligent photonics, including optical communications, optical perception, and optical chip. He has published >300 journal papers (including Science) and conference proceedings with >14,000 citations, two books (Elsevier, Springer Nature), eight edited books, two book chapters, >50 issued patents (including 30 U.S. patents and 6 European patents), >200 invited presentations (including 1 tutorial, >30 plenary and >100 keynote talks). Dr. Yue is a Fellow of Optica and SPIE. He is an Associate Editor for IEEE Access and Frontiers in Physics, Editor Board Member for four other scientific journals, Guest Editor for >10 journal special issues. He also served as Chair for >100 international conferences, Reviewer for >80 prestigious journals.