This book presents new frontiers in data communication. To transcend the physical limitations of current optical communication technologies, totally new multiplexing schemes beyond TDM/WDM, novel transmission optical fibers handling well above Pbit/s capacity, and next-generation optical submarine cable systems will need to be developed. The book offers researchers working at the forefront, as well as advanced Ph.D. students in the area of optical fiber communications systems and related fields, an essential guide to state-of-the-art optical transmission technologies. It explores promising new technologies for the exabit era; namely, the three “M technologies”: multi-level modulation, multi-core fiber, and multi-mode control.
Due to the renewed demand on data bandwidth imposed by the upcoming capacity crunch, optical communication (research and industry) community has oriented their effort to space division multiplexing (SDM) and particularly to mode division multiplexing (MDM). This is based on separate/independent and orthogonal spatial modes of optical fiber as data carriers along optical fiber. Orbital Angular Momentum (OAM) is one of the variants of MDM that showed promising features including the efficient enhancement of capacity transmission from Tbit to Pbit and substantial improvement of spectral efficiency up to hundreds (bs-1 Hz-1). In this chapter, we review the potentials of harnessing SDM as a promising solution for next generation global communications systems. We focus on different SDM approaches and we address specifically the MDM (different modes in optical fiber). Finally, we highlight the recent main works and achievements that have been conducted (in last decade) in OAM-MDM over optical fibers. We focus on main R&D activities incorporating specialty fibers that have been proposed, designed and demonstrating in order to handle appropriates OAM modes.
[ANGLÈS] The combination of Shannon's information theory and Kerr nonlinear effects present in single-mode fibers has recently revealed an approaching capacity crunch of current optical communication systems. A promising solution that is currently being studied relies on space division multiplexing (SDM), which explores the new spatial dimension given by novel few-mode fiber (FMF) or mutli-core fiber (MCF) designs. Along this work, we present two new distance records in wavelength- and space-division multiplexed (WDM-SDM) transmission based on few-mode fibers, at which novel low-loss spot-based multiplexers were used to launch the signals into the fiber modes. First, 5x3x2 wavelength-, space- and polarization-division multiplexed 40 Gb/s QPSK signals were transmitted along 209 km of a hybrid FMF span by means of distributed backwards Raman amplification. Next, a 700-km distance is achieved in a recirculating loop experiment transmitting an aggregate capacity of 4.8 Tb/s over a graded-index FMF span. In both fiber spans a DGD-compensating technique was applied to keep a reduced impulse response of the whole system. The performance observed in both experiments demonstrates the potential of FMF-based space-division multiplexing as a perfect candidate for future high-capacity optical communication transmission systems.
Optical fiber communication has emerged as a high potential substitute for communication methods such as twisted pair and coaxial wire. The main advantage of optical fiber over previous methods is to have higher capacity of data rate transmission. The conventional types of modulation and demodulation technique, which have been used through optical fiber communication system are Wavelength Division Multiplexing (WDM) technique and Dense Wavelength Division Multiplexing (DWDM) technique so far.
At the beginning of an exciting new era in optical communications, we review fundamentals as well as practical experimental aspects of MIMO-SDM: we discuss the importance of selectively addressing all modes of a coupled-mode SDM channel at transmitter and receiver in order to achieve reliable capacity gains and show that reasonable levels of mode-dependent loss (MDL) are acceptable without much loss of channel capacity. We then introduce MIMO-DSP techniques as an extension of familiar algorithms used in polarization-division multiplexed (PDM) digital coherent receivers and discuss their functionality and scalability. Finally, we review the design of mode multiplexers (MMUXs) that allow for the mapping of the individual transmission signals onto an orthogonal basis of waveguide mode, and discuss their performance in experimental demonstrations.
The spatial-division multiplexing (SDM) is a promising technique to increase capacity of the optical communications systems. These systems are currently approaching their fundamental limit. Therefore, a new paradigm is needed to keep up the demands in trafic growth. SDM takes advantage of the space dimension on the optic waveguides to send independent signals at the same time, hence the capacity can be increased considerably. In this work SDM is analyzed over few-mode fibers (FMFs) and multi-core fibers (MCFs). These waveguides are strongly coupled and multiple-input-multiple-output (MIMO) dig- ital signal processing (DSP) is required at the receiver to recover the transmitted signals. The least-mean square (LMS) adaptive algorithm and the fourth power algorithm are both explained and applied successfully to data obtained at the laboratory. Diferent experiments are reported in which the record single span 137-km transmission over FMF is achieved and up to 1200-km over MCF are reached. Moreover, the rst experimental mode-equalized optical distributed Raman amplication is demonstrated. The diffrent experimental results presented here confirm that SDM can provide the basis for a cost-, energy,- and spatial- ecient systems to increase the capacity of the ber-optic communications in the future.
Galileo Unbound traces the journey that brought us from Galileo's law of free fall to today's geneticists measuring evolutionary drift, entangled quantum particles moving among many worlds, and our lives as trajectories traversing a health space with thousands of dimensions. Remarkably, common themes persist that predict the evolution of species as readily as the orbits of planets or the collapse of stars into black holes. This book tells the history of spaces of expanding dimension and increasing abstraction and how they continue today to give new insight into the physics of complex systems. Galileo published the first modern law of motion, the Law of Fall, that was ideal and simple, laying the foundation upon which Newton built the first theory of dynamics. Early in the twentieth century, geometry became the cause of motion rather than the result when Einstein envisioned the fabric of space-time warped by mass and energy, forcing light rays to bend past the Sun. Possibly more radical was Feynman's dilemma of quantum particles taking all paths at once — setting the stage for the modern fields of quantum field theory and quantum computing. Yet as concepts of motion have evolved, one thing has remained constant, the need to track ever more complex changes and to capture their essence, to find patterns in the chaos as we try to predict and control our world.
The first book on optical OFDM by the leading pioneers in the field The only book to cover error correction codes for optical OFDM Gives applications of OFDM to free-space communications, optical access networks, and metro and log haul transports show optical OFDM can be implemented Contains introductions to signal processing for optical engineers and optical communication fundamentals for wireless engineers This book gives a coherent and comprehensive introduction to the fundamentals of OFDM signal processing, with a distinctive focus on its broad range of applications. It evaluates the architecture, design and performance of a number of OFDM variations, discusses coded OFDM, and gives a detailed study of error correction codes for access networks, 100 Gb/s Ethernet and future optical networks. The emerging applications of optical OFDM, including single-mode fiber transmission, multimode fiber transmission, free space optical systems, and optical access networks are examined, with particular attention paid to passive optical networks, radio-over-fiber, WiMAX and UWB communications. Written by two of the leading contributors to the field, this book will be a unique reference for optical communications engineers and scientists. Students, technical managers and telecom executives seeking to understand this new technology for future-generation optical networks will find the book invaluable. William Shieh is an associate professor and reader in the electrical and electronic engineering department, The University of Melbourne, Australia. He received his M.S. degree in electrical engineering and Ph.D. degree in physics both from University of Southern California. Ivan Djordjevic is an Assistant Professor of Electrical and Computer Engineering at the University of Arizona, Tucson, where he directs the Optical Communications Systems Laboratory (OCSL). His current research interests include optical networks, error control coding, constrained coding, coded modulation, turbo equalization, OFDM applications, and quantum error correction. "This wonderful book is the first one to address the rapidly emerging optical OFDM field. Written by two leading researchers in the field, the book is structured to comprehensively cover any optical OFDM aspect one could possibly think of, from the most fundamental to the most specialized. The book adopts a coherent line of presentation, while striking a thoughtful balance between the various topics, gradually developing the optical-physics and communication-theoretic concepts required for deep comprehension of the topic, eventually treating the multiple optical OFDM methods, variations and applications. In my view this book will remain relevant for many years to come, and will be increasingly accessed by graduate students, accomplished researchers as well as telecommunication engineers and managers keen to attain a perspective on the emerging role of OFDM in the evolution of photonic networks." -- Prof. Moshe Nazarathy, EE Dept., Technion, Israel Institute of Technology The first book on optical OFDM by the leading pioneers in the field The only book to cover error correction codes for optical OFDM Applications of OFDM to free-space communications, optical access networks, and metro and log haul transports show optical OFDM can be implemented An introduction to signal processing for optical communications An introduction to optical communication fundamentals for the wireless engineer
This book analyzes novel possibilities offered to the telecommunication engineer in designing tomorrow’s optical networks. Currently, optical and optoelectronic technologies make possible the realization of high-performance optical fiber communication systems and networks with the adoption of WDM configurations and both linear and nonlinear optical amplifications. The last step for increasing network throughput is represented by the implementation of multidimensional modulation formats in coherent optical communication systems, which enable increasing the bit rate/channel toward 400 Gbit/s/channel and beyond. Following this approach, the main emphasis is placed on innovative optical modulations. Multidimensional Modulations in Optical Communication Systems is an essential guide to the world of innovative optical communications from the point of view of growing capacity and security. It guides researchers and industries with the aim to exploring future applications for optical communications.
The always increasing need for digital data bandwidth pushes the development of emerging technologies to increase network capacity, especially for optical fiber infrastructures. Among those technologies, spatial multiplexing is a promising way to multiply the capacity of current optical links. In this thesis, we are particularly interested in current spatial multiplexing using the orbital angular momentum of light as an orthogonal basis to distinguish between a few optical channels. We first introduce notions from electromagnetism and physic needed for the understanding of the later developments. We derive Maxwell's equations describing scalar and vector modes of optical fiber. We also present other modal properties like mode cutoff, group index, and dispersion. Orbital angular momentum is briefly explained, with emphasis on its applications to optical communications. In the second part, we propose the modal map as a tool that can help in the design of few mode fibers. We develop the vectorial solution of the ring-core fiber cutoff equation, then we extend those equations to all varieties of three-layer fiber profiles. Finally, we give some examples of the use of the modal map. In the third part of this thesis, we propose few fiber designs for the transmission of modes with an orbital angular momentum. The tools that were developed in the second part of this thesis are now used in the design process of those fibers. A first fiber design, characterized by a hollow center, is studied and demonstrated. Then a second design, a family of ring-core fibers, is studied. Effective indexes and group indexes are measured on the fabricated fibers, and compared to numerical simulations. The tools and the fibers developed in this thesis allowed a deeper comprehension of the transmission of orbital angular momentum modes in fiber. We hope that those achievements will help in the development of next generation optical communication systems using spatial multiplexing.
