Academic Press Optical Fiber Telecommunications Volume A Components And Subsystems 5th Edition Feb 2008 ISBN 0123741718 pdf
Optical Fiber Telecommunications V A About the Editors
Ivan P. Kaminow retired from Bell Labs in 1996 after a 42-year career. He conducted seminal studies on electrooptic modulators and materials, Raman scatter- ing in ferroelectrics, integrated optics, semiconductor lasers (DBR, ridge-waveguide InGaAsP, and multi-frequency), birefringent optical fibers, and WDM networks. Later, he led research on WDM components (EDFAs, AWGs, and fiber Fabry-Perot Filters), and on WDM local and wide area networks. He is a member of the National Academy of Engineering and a recipient of the IEEE/OSA John Tyndall, OSA Charles Townes, and IEEE/LEOS Quantum Electronics Awards. Since 2004, he has been Adjunct Professor of Electrical Engineering at the University of California, Berkeley. Tingye Li retired from AT&T in 1998 after a 41-year career at Bell Labs and AT&T Labs. His seminal work on laser resonator modes is considered a classic. Since the late 1960s, he and his groups have conducted pioneering studies on lightwave technologies and systems. He led the work on amplified WDM trans- mission systems and championed their deployment for upgrading network capa- city. He is a member of the National Academy of Engineering and a foreign member of the Chinese Academy of Engineering. He is also a recipient of the
IEEE David Sarnoff Award, IEEE/OSA John Tyndall Award, OSA Ives Medal/ Quinn Endowment, AT&T Science and Technology Medal, and IEEE Photonics Award.
Alan E. Willner has worked at AT&T Bell Labs and Bellcore, and he is Professor of Electrical Engineering at the University of Southern California. He received the NSF Presidential Faculty Fellows Award from the White House, Packard Founda- tion Fellowship, NSF National Young Investigator Award, Fulbright Foundation Senior Scholar, IEEE LEOS Distinguished Lecturer, and USC University-Wide Award for Excellence in Teaching. He is a Fellow of IEEE and OSA, and he has been President of the IEEE LEOS, Editor-in-Chief of the IEEE/OSA J. of Lightwave Technology, Editor-in-Chief of Optics Letters, Co-Chair of the OSA Science & Engineering Council, and General Co-Chair of the Conference on Lasers and Electro-Optics.
Optical Fiber Telecommunications V A
Components and Subsystems Edited by Ivan P. Kaminow Tingye Li Alan E. Willner
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This page intentionally left blank Contents
Contributors ix
Chapter 1 Overview of OFT V Volumes A & B
1 Ivan P. Kaminow, Tingye Li, and Alan E. Willner
Chapter 2 Semiconductor Quantum Dots: Genesis—The Excitonic Zoo—Novel Devices for Future Applications
23 Dieter Bimberg
Chapter 3 High-Speed Low-Chirp Semiconductor Lasers
53 Shun Lien Chuang, Guobin Liu, and Piotr Konrad Kondratko
Chapter 4 Recent Advances in Surface-Emitting Lasers
81 Fumio Koyama
Chapter 5 Pump Diode Lasers 107 Christoph Harder Chapter 6 Ultrahigh-Speed Laser Modulation by Injection Locking 145 Connie J. Chang-Hasnain and Xiaoxue Zhao Chapter 7 Recent Developments in High-Speed Optical Modulators 183
Lars Thyle´n, Urban Westergren, Petter Holmstro¨m, Richard Schatz, and Peter Ja¨nes
Chapter 8 Advances in Photodetectors 221 Joe Charles Campbell Chapter 9 Planar Lightwave Circuits in Fiber-Optic Communications 269 Christopher R. Doerr and Katsunari Okamoto Chapter 10 III–V Photonic Integrated Circuits and Their Impact on Optical Network Architectures 343 Dave Welch, Chuck Joyner, Damien Lambert, Peter W. Evans, and Maura Raburn
Chapter 11 Silicon Photonics 381 Cary Gunn and Thomas L. Koch Chapter 12 Photonic Crystal Theory: Temporal Coupled-Mode Formalism 431
Shanhui Fan
Chapter 13 Photonic Crystal Technologies: Experiment 455 Susumu Noda Chapter 14 Photonic Crystal Fibers: Basics and Applications 485 Philip St John Russell Chapter 15 Specialty Fibers for Optical Communication Systems 523 Ming-Jun Li, Xin Chen, Daniel A. Nolan, Ji Wang, James A. West, and Karl W. Koch Chapter 16 Plastic Optical Fibers: Technologies and Communication Links 593
Yasuhiro Koike and Satoshi Takahashi
Chapter 17 Polarization Mode Dispersion 605 Misha Brodsky, Nicholas J. Frigo, and Moshe Tur Chapter 18 Electronic Signal Processing for Dispersion Compensation and Error Mitigation in Optical Transmission Networks 671 Abhijit Shanbhag, Qian Yu, and John Choma
Chapter 19 Microelectromechanical Systems for Lightwave Communication 713 Ming C. Wu, Olav Solgaard, and Joseph E. Ford Chapter 20 Nonlinear Optics in Communications: From Crippling Impairment to Ultrafast Tools 759 Stojan Radic, David J. Moss, and Benjamin J. Eggleton Chapter 21 Fiber-Optic Quantum Information Technologies 829 Prem Kumar, Jun Chen, Paul L. Voss, Xiaoying Li, Kim Fook Lee, and Jay E. Sharping Index to Volumes VA and VB 881
viii Contents
Contributors
Dieter Bimberg, Institut fuer Festkoerperphysik and Center of Nanophotonics, Berlin, Germany, [email protected] Misha Brodsky, AT&T Labs – Research, Middletown, NJ, USA, [email protected] Joe Charles Campbell, School of Engineering and Applied Science, Department of Electrical and Computer Engineering, University of Virginia, Charlottesville, VA, USA, [email protected] Connie J. Chang-Hasnain, Department of Electrical Engineering and Computer Sciences, University of California, Berkeley, CA, USA, [email protected] Jun Chen, Center for Photonic Communication and Computing, EECS Department, Northwestern University, Evanston, IL, USA Xin Chen, Corning Inc., Corning, NY, USA, [email protected] John Choma, Scintera Inc., Sunnyvale, CA, USA, [email protected] Shun Lien Chuang, Department of ECE, University of Illinois, Urbana, IL, USA, [email protected] Christopher R. Doerr, Alcatel-Lucent, Holmdel, NJ, USA, [email protected] Benjamin J. Eggleton, ARC Centre of Excellence for Ultrahigh-bandwidth Devices for Optical Systems (CUDOS), School of Physics, University of Sydney, Australia, [email protected] Peter W. Evans, Infinera Inc., Sunnyvale, CA, USA, [email protected] Shanhui Fan, Ginzton Laboratory, Department of Electrical Engineering, Stanford, CA, USA, [email protected] Joseph E. Ford, Department of Electrical and Computer Engineering, x Contributors
Nicholas J. Frigo, Department of Physics, U.S. Naval Academy, Annapolis, MD, USA, [email protected] Cary Gunn, Chief Technology Officer, Luxtera, Inc., Carlsbad, CA, USA, [email protected] Christoph Harder, HPP, Etzelstrasse 58, Schindellegi, Switzerland, [email protected] Petter Holmstro¨m, Department of Microelectronics and Applied Physics, Royal Institute of Technology (KTH), Kista, Sweden, [email protected] Peter Ja¨nes, Proximion Fiber Systems AB, Kista, Sweden, [email protected] Chuck Joyner, Infinera Inc., Sunnyvale, CA, USA, [email protected] Ivan P. Kaminow, 254M Cory Hall #1770, University of California, Berkeley, CA, USA, [email protected] Karl W. Koch, Corning Inc., Corning, NY, USA, [email protected] Thomas L. Koch, Center for Optical Technologies, Sinclair Laboratory, Lehigh University, Bethlehem, PA, USA, [email protected] Yasuhiro Koike, Keio University ERATO Koike Photonics Polymer Project, Yokohama, Japan, [email protected] Piotr Konrad Kondratko, Department of ECE, University of Illinois, Urbana, IL, USA, [email protected] Fumio Koyama, Microsystem Research Center, P&I Lab, Tokyo Institute of Technology, Nagatsuta, Midori-ku, Yokohama, Japan, [email protected] Prem Kumar, Technological Institute, Northwestern University, Evanston, IL, USA, [email protected] Damien Lambert, Infinera Inc., Sunnyvale, CA, USA, [email protected] Kim Fook Lee, Center for Photonic Communication and Computing, EECS Department, Northwestern University, Evanston, IL, USA Ming-Jun Li, Corning Inc., Corning, NY, USA, [email protected]
Contributors xi
Xiaoying Li, Center for Photonic Communication and Computing, EECS Department, Northwestern University, Evanston, IL, USA Guobin Liu, Department of ECE, University of Illinois, Urbana, IL, USA, [email protected] David J. Moss, ARC Centre of Excellence for Ultrahigh-bandwidth Devices for Optical Systems (CUDOS), School of Physics, University of Sydney, Australia, [email protected] Susumu Noda, Department of Electronic Science and Engineering, Kyoto University, Kyoto, Japan, [email protected] Daniel A. Nolan, Corning Inc., Corning, NY, USA, [email protected] Katsunari Okamoto, Okamoto Laboratory, 2-1-33 Higashihara, Mito-shi, Ibaraki-ken, 310-0035, Japan, [email protected] Maura Raburn, Infinera Inc., Sunnyvale, CA, USA, [email protected] Stojan Radic, Department of Electrical and Computer Engineering, University of California, San Diego, La Jolla, CA, USA, [email protected] Philip St. John Russell, Max-Planck Research Group (IOIP), University of Erlangen-Nuremberg, Erlangen, Germany, [email protected] Richard Schatz, Department of Microelectronics and Applied Physics, Royal Institute of Technology (KTH), Kista, Sweden, [email protected] Abhijit Shanbhag, Scintera Inc., Sunnyvale, CA, USA, [email protected] Jay E. Sharping, University of California, Merced, CA, [email protected] Olav Solgaard, Department of Electrical Engineering, Edward L. Ginzton Laboratory, Stanford University, Stanford, CA, USA, [email protected] Satoshi Takahashi, The Application Group, Shin-Kawasaki Town Campus, Keio University, Kawasaki, Japan, [email protected] Lars Thyle´n, Department of Microelectronics and Applied Physics, Royal Institute of Technology (KTH), Kista, Sweden, [email protected] Moshe Tur, School of Electrical Engineering, Tel Aviv University, Ramat Aviv, Israel, [email protected] Paul L. Voss, Center for Photonic Communication and Computing, EECS xii Contributors
Ji Wang, Corning Inc., Corning, NY, USA, [email protected] Dave Welch, Infinera Inc., Sunnyvale, CA, USA, [email protected] James A. West, Corning Inc., Corning, NY, USA, [email protected] Urban Westergren, Department of Microelectronics and Applied Physics, Royal Institute of Technology (KTH), Kista, Sweden, [email protected] Alan E. Willner, Ming Hsieh Department of Electrical Engineering, Viterbi School of Engineering, University of Southern California, Los Angeles, CA, USA, [email protected] Ming C. Wu, Berkeley Sensor and Actuator Center (BSAC) and Electrical Engineering & Computer Science Department, University of California, Berkeley, CA, USA, [email protected] Qian Yu, Scintera Inc., Sunnyvale, CA, USA, [email protected] Xiaoxue Zhao, Department of Electrical Engineering and Computer Sciences, University of California, Berkeley, CA, USA, [email protected]
1 Overview of OFT V volumes A & B
† ‡ *
Ivan P. Kaminow , Tingye Li , and Alan E. Willner
- University of California, Berkeley, CA, USA
† Boulder, CO, USA
‡ University of Southern California, Los Angeles, CA, USA
Optical Fiber Telecommunications V (OFT V) is the fifth installment of the OFT series. Now 29 years old, the series is a compilation by the research and devel- opment community of progress in optical fiber communications. Each edition reflects the current state-of-the-art at the time. As Editors, we started with a clean slate of chapters and authors. Our goal was to update topics from OFT IV that are still relevant as well as to elucidate topics that have emerged since the last edition.
1.1 FIVE EDITIONS
Installments of the series have been published roughly every 6–8 years and chronicle the natural evolution of the field:
- In the late 1970s, the original OFT (Chenoweth and Miller, 1979) was concerned with enabling a simple optical link, in which reliable fibers, connectors, lasers, and detectors played the major roles.
- In the late 1980s, OFT II (Miller and Kaminow, 1988) was published after the first field trials and deployments of simple optical links. By this time, the advantages of multiuser optical networking had captured the imagination of the community and were highlighted in the book.
- OFT III (Kaminow and Koch, 1997) explored the explosion in transmission capacity in the early-to-mid 1990s, made possible by the erbium-doped fiber amplifier (EDFA), wavelength division multiplexing (WDM), and dispersion management.
Optical Fiber Telecommunications V A: Components and Subsystems
Ivan P. Kaminow et al.
- By 2002, OFT IV (Kaminow and Li, 2002) dealt with extending the distance and capacity envelope of transmission systems. Subtle nonlinear and disper- sive effects, requiring mitigation or compensation in the optical and electrical domains, were explored.
- The present edition of OFT, V, (Kaminow, Li, and Willner, 2008) moves the series into the realm of network management and services, as well as employ- ing optical communications for ever-shorter distances. Using the high band- width capacity in a cost-effective manner for customer applications takes center stage. In addition, many of the topics from earlier volumes are brought up to date; and new areas of research which show promise of impact are featured.
Although each edition has added new topics, it is also true that new challenges emerge as they relate to older topics. Typically, certain devices may have ade- quately solved transmission problems for the systems of that era. However, as systems become more complex, critical device technologies that might have been considered a “solved problem” previously have new requirements placed upon them and need a fresh technical treatment. For this reason, each edition has grown in sheer size, i.e., adding the new and, if necessary, reexamining the old.
An example of this circular feedback mechanism relates to the fiber itself. At first, systems simply required low-loss fiber. However, long-distance transmission enabled by EDFAs drove research on low-dispersion fiber. Further, advances in WDM and the problems of nonlinear effects necessitated development of nonzero dispersion fiber. Cost considerations and ultra-high-performance systems, respectively, are driv- ing research in plastic fibers and ultra-low-polarization-dependent fibers. We believe that these cycles will continue. Each volume includes a CD-ROM with all the figures from that volume. Select figures are in color. The volume B CD-ROM also has some supplementary Powerpoint slides to accompany Chapter 19 of that volume.
1.2 PERSPECTIVE OF THE PAST 6 YEARS
Our field has experienced an unprecedented upheaval since 2002. The irrational exuberance and despair of the technology “bubble-and-bust” had poured untold sums of money into development and supply of optical technologies, which was followed by a depression-like period of over supply. We are happy to say that, by nearly all accounts, the field is gaining strength again and appears to be entering a stage of rational growth.
What caused this upheaval? A basis seems to be related to a fundamental discontinuity in economic drivers. Around 2001, worldwide telecom traffic ceased being dominated by the slow-growing voice traffic and was overtaken by the rapidly growing Internet traffic. The business community over-estimated the
1. Overview of OFT V Volumes A & B
growth rate, which generated enthusiasm and demand, leading to unsustainable expectations. Could such a discontinuity happen again? Perhaps, but chastened investors now seem to be following a more gradual and sensible path. Throughout the “bubble-and-bust” until the present, the actual demand for bandwidth has grown at a very healthy
80% per year globally; thus, real traffic demand experienced no bubble at all. The growth and capacity needs are real, and should continue in the future.
As a final comment, we note that optical fiber communications is firmly entrenched as part of the global information infrastructure. The only question is how deeply will it penetrate and complement other forms of communications, e.g., wireless, access, and on-premises networks, interconnects, satellites, etc. This prospect is in stark contrast to the voice-based future seen by OFT, published in 1979, before the first commercial intercontinental or transatlantic cable systems were deployed in the 1980s. We now have Tb/s systems for metro and long-haul networks. It is interesting to contemplate what topics and concerns might appear in OFT VI .
1.3 OFT V VOLUME A: COMPONENTS AND SUBSYSTEMS
1.3.1 Chapter 1. Overview of OFT V volumes A & B
( Ivan P. Kaminow, Tingye Li, and Alan E. Willner)
This chapter briefly reviews herewith all the chapters contained in both volumes of OFT V.
1.3.2 Chapter 2. Semiconductor quantum dots: Genesis—The Excitonic Zoo—novel devices for future applications ( Dieter Bimberg)
The ultimate class of semiconductor nanostructures, i.e., “quantum dots” (QDs), is based on “dots” smaller than the de Broglie wavelength in all three dimensions. They constitute nanometer-sized clusters that are embedded in the dielectric matrix of another semiconductor. They are often self-similar and can be formed by self-organized growth on surfaces. Single or few quantum dots enable novel devices for quantum information processing, and billions of them enable active centers in optoelectronic devices like QD lasers or QD optical amplifiers. This chapter covers the area of quantum dots from growth via various band structures to optoelectronic device applications. In addition, high-speed laser and amplifier operations are described.
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1.3.3 Chapter 3. High-speed low-chirp semiconductor lasers
( Shun Lien Chuang, Guobin Liu, and Piotr Konrad
Kondratko)One advantage of using quantum wells and quantum dots for the active region of lasers is the lower induced chirp when such lasers are directly modulated, permit- ting direct laser modulation that can save on the cost of separate external modulators. This chapter provides a comparison of InAlGaAs with InGaAsP long-wavelength quantum-well lasers in terms of high-speed performance, and extracts the important parameters such as gain, differential gain, photon lifetime, temperature dependence, and chirp. Both DC characteristics and high-speed direct modulation of quantum-well lasers are presented, and a comparison with theore- tical models is made. The chapter also provides insights into novel quantum-dot lasers for high-speed operation, including the ideas of p-type doping vs tunneling injection for broadband operation.
1.3.4 Chapter 4. Recent advances in surface-emitting lasers
( Fumio Koyama)Vertical cavity surface-emitting lasers (VCSELs) have a number of special proper- ties (compared with the more familiar edge-emitting lasers) that permit some novel applications. This chapter begins with an introduction which briefly surveys recent advances in VCSELs, several of that are then treated in detail. These include techniques for realizing long-wavelength operation (as earlier VCSELs were limited to operation near 850 nm), the performance of dense VCSEL arrays that emit a range of discrete wavelengths (as large as 110 in number), and MEMS- based athermal VCSELs. Also, plasmonic VCSELs that produce subwavelength spots for high-density data storage and detection are examined. Finally, work on all-optical signal processing and slow light is presented.
1.3.5 Chapter 5. Pump diode lasers ( Christoph Harder)
Erbium-doped fiber amplifiers (EDFAs) pumped by bulky argon lasers were known for several years before telecom system designers took them seriously; the key development was a compact, high-power semiconductor pump laser. Considerable effort and investment have gone into today’s practical pump lasers, driven by the importance of EDFAs in realizing dense wavelength division multi- plexed (DWDM) systems. The emphasis has been on high power, efficiency, and reliability. The two main wavelength ranges are in the neighborhood of 980 nm for low noise and 1400 nm for remote pumping of EDFAs. The 1400-nm band is also suitable for Raman amplifiers, for which very high power is needed.
1. Overview of OFT V Volumes A & B
This chapter details the many lessons learned in the design for manufacture of commercial pump lasers in the two bands. Based on the performance developed for telecom, numerous other commercial applications for high-power lasers have emerged in manufacturing and printing; these applications are also discussed.
1.3.6 Chapter 6. Ultrahigh-speed laser modulation by
injection locking ( Connie J. Chang-Hasnain and
Xiaoxue Zhao)It has been known for decades that one oscillator (the slave) can be locked in frequency and phase to an external oscillator (the master) coupled to it. Current studies of injection-locked lasers show that the dynamic characteristics of the directly modulated slave are much improved over the same laser when freely running. Substantial improvements are found in modulation bandwidth for analog and digital modulation, in linearity, in chirp reduction and in noise performance.
In this chapter, theoretical and experimental aspects of injection locking in all lasers are reviewed with emphasis on the authors’ research on VCSELs (vertical cavity surface-emitting lasers). A recent promising application in passive optical networks for fiber to the home (FTTH) is also discussed.
1.3.7 Chapter 7. Recent developments in high-speed optical modulators ( Lars Thyle´n, Urban Westergren,
Petter Holmstro¨m, Richard Schatz, and Peter Ja¨nes)
Current high-speed lightwave systems make use of electro-optic modulators based on lithium niobate or electroabsorption modulators based on semiconductor materi- als. In commercial systems, the very high-speed lithium niobate devices often require a traveling wave structure, while the semiconductor devices are usually lumped.
This chapter reviews the theory of high-speed modulators (at rates of 100 Gb/s) and then considers practical design approaches, including comparison of lumped and traveling-wave designs. The main emphasis is on electroabsorption devices based on Franz–Keldysh effect, quantum-confined Stark effect and intersubband absorption. A number of novel designs are described and experimental results given.
1.3.8 Chapter 8. Advances in photodetectors ( Joe Charles Campbell)
As a key element in optical fiber communications systems, photodetectors belong to a well developed sector of photonics technology. Silicon p–i–n and avalanche photo- diodes deployed in first-generation lightwave transmission systems operating at 0.82-
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were developed and commercialized for systems that operated at 1.3- and 1.5- mm wavelengths, albeit the avalanche photodiodes (APDs) were expensive and nonideal. Introduction of erbium-doped fiber amplifiers and WDM technology in the 1990s relegated APDs to the background, as p–i–n photoreceivers performed well in amplified systems, whereas APDs were plagued by the amplified spontaneous emission noise. Future advanced systems and special applications will require sophisticated devices involving deep understanding of device physics and technology. This chapter focuses on three primary topics: high-speed waveguide photodiodes for systems that operate at 100 Gb/s and beyond, photodiodes with high saturation current for high-power applica- tions, and recent advances of APDs for applications in telecommunications.
1.3.9 Chapter 9. Planar lightwave circuits in fiber-optic communications ( Christopher R. Doerr and Katsunari Okamoto)
The realization of one or more optical waveguide components on a planar substrate has been under study for over 35 years. Today, individual components such as splitters and arrayed waveguide grating routers (AWGRs) are in widespread commercial use. Sophisticated functions, such as reconfigurable add–drop multiplexers (ROADMs) and high-performance filters, have been demonstrated by integrating elaborate combinations of such components on a single chip. For the most part, these photonic integrated circuits (PICs), or planar lightwave circuits (PLCs), are based on passive waveguides in lower index materials, such as silica.
This chapter deals with the theory and design of such PICs. The following two chapters (Chapters 11 and 12) also deal with PICs; however, they are designed to be integrated with silicon electronic ICs, either in hybrid fashion by short wire bonds to an InP PIC or directly to a silicon PIC.
1.3.10 Chapter 10. III–V photonic integrated circuits and their impact on optical network architectures ( Dave Welch, Chuck Joyner, Damien Lambert, Peter W. Evans, and Maura Raburn)
InP-based semiconductors are unique in their capability to support all the photonic components required for wavelength division multiplexed (WDM) transmitters and receivers in the telecom band at 1550 nm. Present subsystems have connected these individual components by fibers or lenses to form hybrid transmitters and receivers for each channel.
Recently, integrated InP WDM transmitter and receiver chips that provide
1. Overview of OFT V Volumes A & B
economically viable for deployment in commercial WDM systems. The photonic integrated circuits are wire-bonded to adjacent silicon ICs. Thus a single board provides optoelectronic regeneration for 10 channels, dramatically reducing interconnection complexity and equipment space. In addition, as in legacy single- channel systems, the “digital” approach for transmission (as compared to “all-optical”) offers ease of network monitoring and management. This chapter covers the technology of InP photonic integrated circuits (PICs) and their commercial application. The impact on optical network architecture and operation is discussed and technology advances for future systems are presented.
1.3.11 Chapter 11. Silicon photonics ( Cary Gunn and Thomas L. Koch)
Huge amounts of money have been invested in silicon processing technology, thanks to a steady stream of applications that justified the next stage of proces- sing development. In addition to investment, innovative design, process disci- pline and large-volume runs made for economic success. The InP PICs described in the previous chapter owe their success to lessons learned in silicon IC processing.
Many people have been attracted by the prospects of fabricating PICs using silicon alone to capitalize on the investment and success of silicon ICs. To succeed one requires a large-volume application and a design that can be made in an operating silicon IC foundry facility. A further potential advantage is the oppor- tunity to incorporate on the same photonic chip electronic signal processing. The application to interconnects for high-performance computers is a foremost motiva- tion for this work.
While silicon has proven to be the ideal material for electronic ICs, it is far from ideal for PICs. The main shortcoming is the inability so far to make a good light source or photodetector in silicon. This chapter discusses the successes and challenges encountered in realizing silicon PICs to date.
1.3.12 Chapter 12. Photonic crystal theory: Temporal coupled-mode formalism ( Shanhui Fan)
Photonic crystal structures have an artificially created optical bandgap that is introduced by a periodic array of perturbations, and different types of wave- guides and cavities can be fabricated that uniquely use the band gap-based confinement. These artificially created materials have been of great interest for potential optical information processing applications, in part because they pro- vide a common platform to miniaturize a large number of optical components on-chip down to single wavelength scale. For this purpose, many devices can be
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designed using such a material with a photonic bandgap and, subsequently, introducing line and point defect states into the gap. Various functional devices, such as filters, switches, modulators and delay lines, can be created by control- ling the coupling between these defect states. This chapter reviews the temporal coupled-mode theory formalism that provides the theoretical foundation of many of these devices.
1.3.13 Chapter 13. Photonic crystal technologies: Experiment ( Susumu Noda)
Photonic crystals belong to a class of optical nanostructures characterized by the formation of band structures with respect to photon energy. In 3D photonic crystals, a complete photonic band gap is formed; the presence of light with frequencies lying in the band gap is not allowed. This chapter describes the application of various types of materials engineering to photonic crystals, with particular focus on the band gap/defect, the band edge, and the transmission band within each band structure. The manipulation of photons in a variety of ways becomes possible. Moreover, this chapter discusses the recent introduction of “photonic heterostructures” as well as recent developments concerning two- and three-dimensional photonic crystals.
1.3.14 Chapter 14. Photonic crystal fibers: Basics and applications ( Philip St John Russell)
Photonic crystal fibers (PCFs)—fibers with a periodic transverse microstructure— first emerged as practical low-loss waveguides in early 1996. The initial demon- stration took 4 years of technological development, and since then the fabrication techniques have become more and more sophisticated. It is now possible to manufacture the microstructure in air–glass PCFs to accuracies of 10 nm on the scale of 1 mm, which allows remarkable control of key optical properties such as dispersion, birefringence, nonlinearity and the position and width of the photonic band gaps (PBGs) in the periodic “photonic crystal” cladding. PCF has in this way extended the range of possibilities in optical fibers, both by improving well- established properties and introducing new features such as low-loss guidance in a hollow core.
In this chapter, the properties of the various types of PCFs are introduced, followed by a detailed discussion of their established or emerging applications. The chapter describes in detail the fabrication, theory, numerical modeling, optical properties, and guiding mechanisms of PCFs. Applications of photonic crystal fibers include lasers, amplifiers, dispersion compensators, and nonlinear
1. Overview of OFT V Volumes A & B
1.3.15 Chapter 15. Specialty fibers for optical
communication systems ( Ming-Jun Li, Xin Chen,
Daniel A. Nolan, Ji Wang, James A. West, and
Karl W. Koch)Specialty fibers are designed by changing fiber glass composition, refractive index profile, or coating to achieve certain unique properties and functionalities. Some of the common specialty fibers include active fibers, polarization control fibers, dispersion compensation fibers, highly nonlinear fibers, coupling or bridge fibers, high-numerical-aperture fibers, fiber Bragg gratings, and special single mode fibers. In this chapter, the design and performance of various specialty fibers are discussed. Special attention is paid to dispersion compensation fibers, polarization- maintaining and single-polarization fibers, highly nonlinear fibers, double clad fiber for high-power lasers and amplifiers, and photonic crystal fibers. Moreover, there is a brief discussion of the applications of these specialty fibers.
1.3.16 Chapter 16. Plastic optical fibers: Technologies
and communication links ( Yasuhiro Koike and
Satoshi Takahashi)Plastic optical fiber (POF) consists of a plastic core that is surrounded by a plastic cladding of a refractive index lower than that of the core. POFs have very large core diameters compared to glass optical fibers, and yet they are quite flexible. These features enable easy installation and safe handling. Moreover, the large-core fibers can be connected without high-precision accuracy and with low cost. POFs have been used extensively in short-distance datacom applications, such as in digital audio interfaces. POFs are also used for data transmission within equipment and for control signal transmission in machine tools. During the late 1990s, POFs were used as the transmission medium in the data bus within automobiles. As we move into the future, high-speed communication will be required in the home, and POFs are a promising candidate for home network wiring. This chapter describes the POF design and fabrication, the specific fiber properties of attenuation, band- width and thermal stability, and various communications applications, concluding with a discussion of recent developments in graded-index POFs.
1.3.17 Chapter 17. Polarization mode dispersion ( Misha Brodsky, Nicholas J. Frigo, and Moshe Tur)
Polarization-mode dispersion (PMD) has been well recognized for sometime as an impairment factor that limits the transmission speed and distance in high-speed lightwave systems. The complex properties of PMD have enjoyed scrutiny by
Ivan P. Kaminow et al.
theorists, experimentalists, network designers, field engineers and, during the “bubble” years, entrepreneurial technologists. A comprehensive treatment of the subject up to year 2002 is given in a chapter bearing the same title in Optical Fiber Telecommunications IVB, System and Impairments . The present chapter is an overview of PMD with special emphasis on the knowledge accumulated in the past 5 years. It begins with a review of PMD concepts, and proceeds to consider the “hinge” model used to describe field test results, which are presented and analyzed. The important subject of system penalties and outages due to first-order PMD is then examined, followed by deliberations of higher-order PMD, and interaction between fiber nonlinear effects and PMD.
1.3.18 Chapter 18. Electronic signal processing for
dispersion compensation and error mitigation in
optical transmission networks ( Abhijit Shanbhag, Qian Yu, and John Choma)Dispersion equalization has its origin in the early days of analog transmission of voice over copper wires where loading coils (filters) were distributed in the net- work to equalize the frequency response of the transmission line. Digital transmis- sion over twisted pairs was enabled by the invention of the transversal equalizer which extended greatly the bandwidth and reach. Sophisticated signal processing and modulation techniques have now made mobile telephones ubiquitous. How- ever, it was not until the mid 1990s that wide deployment of Gigabit Ethernet rendered silicon CMOS ICs economical for application in high-speed lightwave transmission. Most, if not all lightwave transmission systems deployed today, use electronic forward error correction and dispersion compensation to alleviate signal degradation due to noise and fiber dispersive effects.
This chapter presents an overview of various electronic equalization and adap- tation techniques, and discusses their high-speed implementation, specifically addressing 10-Gb/s applications for local-area, metro, and long-haul networks. It comprises a comprehensive survey of the role, scope, limitations, trends, and challenges of this very important and compelling technology.
1.3.19 Chapter 19. Microelectromechanical systems for
lightwave communication ( Ming C. Wu, Olav
Solgaard, and Joseph E. Ford)The earliest commercial applications of microelectromechanical systems (MEMS) were in digital displays employing arrays of tiny mirrors and in accelerometers for airbag sensors. This technology has now found a host of applications in lightwave communications. These applications usually require movable components, such as
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1. Overview of OFT V Volumes A & B
elements may be called for in some applications. Either a free-space or integrated layout may be used.
This chapter describes the recent lightwave system applications of MEMS. In telecommunications, MEMS switches can provide cross-connects with large numbers of ports. A variety of wavelength selective devices, such as reconfigurable optical add–drop multiplexers (ROADM) employ MEMS. More recent devices include tunable lasers and microdisk resonators.
1.3.20 Chapter 20. Nonlinear optics in communications: from crippling impairment to ultrafast tools ( Stojan
Radic, David J. Moss, and Benjamin J. Eggleton)
It is perhaps somewhat paradoxical that optical nonlinearities, whilst having posed significant limitations for long-haul WDM systems, also offer the promise of addres- sing the bandwidth bottleneck for signal processing for future optical networks as they evolve beyond 40 Gb/s. In particular, all-optical devices based on the 3rd order
(3)
optical nonlinearity offer a significant promise in this regard, not only because
(3) (3)
the intrinsic nonresonant is nearly instantaneous, but also because is responsible for a wide range of phenomena, including 3rd harmonic generation, stimulated Raman gain, four-wave mixing, optical phase conjugation, two-photon absorption, and the nonlinear refractive index. This plethora of physical processes has been the basis for a wide range of activity on all-optical signal processing devices.
This chapter focuses on breakthroughs in the past few years on approaches based on highly nonlinear silica fiber as well as chalcogenide-glass-based fiber and waveguide devices. The chapter contrasts two qualitatively different approaches to all-optical signal processing based on nonphase-matched and phase-matched pro- cesses. All-optical applications of 2R and 3R regeneration, wavelength conver- sion, parametric amplification, phase conjugation, delay, performance monitoring, and switching are reviewed.
1.3.21 Chapter 21. Fiber-optic quantum information technologies ( Prem Kumar, Jun Chen, Paul L. Voss,
Xiaoying Li, Kim Fook Lee, and Jay E. Sharping)
Quantum-mechanical (QM) rules are surprisingly simple: linear algebra and first- order partial differential equations. Yet, QM predictions are unimaginably precise and accurate when compared with experimental data. A “mysterious” feature of QM is the superposition principle and the ensuing quantum entanglement. The funda- mental difference between quantum entanglement and classical correlation lies in the fact that particles are quantum-mechanical objects which can exist not only in states
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can only exist in one of two deterministic states (i.e., “heads” or “tails”), and not something in between. In other words, the individual particle in quantum entangle- ment does not have a well-defined pure state before measurement.
Since the beginning of the 1990s, the field of quantum information and com- munication has expanded rapidly, with quantum entanglement being a critical aspect. Entanglement is still an unresolved “mystery,” but a new world of “quantum ideas” has been ignited and is actively being pursued. The focus of this chapter is the generation of correlated and entangled photons in the telecom band using the Kerr nonlinearity in dispersion-shifted fiber. Of particular interest are microstructure fibers, in which tailorable dispersion properties have allowed phase-matching and entanglement to be obtained over a wide range of wavelengths.
1.4 OFT V VOLUME B: SYSTEMS AND NETWORKS
1.4.1 Chapter 1. Overview of OFT V volumes A & B
( Ivan P. Kaminow, Tingye Li, and Alan E. Willner)
This chapter briefly reviews herewith all the chapters contained in both volumes of OFT V.
1.4.2 Chapter 2. Advanced optical modulation formats ( Peter J. Winzer and Rene´-Jean Essiambre)
Today, digital radio-frequency (rf) communication equipment employs sophisti- cated signal processing and communication theory technology to realize amazing performance; wireless telephones are a prime example. These implementations are made possible by the capabilities and low cost of silicon integrated circuits in high- volume consumer applications. Some of these techniques, such as forward error correction (FEC) and electronic dispersion compensation (EDC) are currently in use in lightwave communications to enhance signal-to-noise ratio and mitigate signal degradation. (See the chapter on “Electronic Signal Processing for Disper- sion Compensation and Error Mitigation in Optical Transmission Networks” by Abhijit Shanbhag, Qian Yu, and John Choma.) Advanced modulation formats that are robust to transmission impairments or able to improve spectral efficiency are being considered for next-generation lightwave systems.
This chapter provides a taxonomy of optical modulation formats, along with experimental techniques for realizing them. The discussion makes clear the sub- stantial distinctions between design conditions for optical and rf applications. Demodulation concepts for coherent and delay demodulation are also covered analytically.
1. Overview of OFT V Volumes A & B
1.4.3 Chapter 3. Coherent optical communication systems ( Kazuro Kikuchi)
The first generation of single-channel fiber optic networks used on-off keying and direct detection. Later, coherent systems, employing homodyne and heterodyne detection, were intensely researched with the aim of taking advantage of their improved sensitivity and WDM frequency selectivity. However, the quick success of EDFAs in the 1990s cut short the prospects for coherent systems.
Now, interest in coherent is being renewed as the need for greater spectral effi- ciency in achieving greater bandwidth per fiber has become apparent. This chapter reviews the theory of multilevel modulation formats that permit multiple bits/s of data per Hz of bandwidth. (See the chapter on “Advanced Modulation Formats” by Winzer and Essiambre.) The growing capabilities of silicon data signal processing (DSP) can be combined with digital coherent detection to provide dramatic improvements in spectral efficiency. Experimental results for such receivers are presented.
1.4.4 Chapter 4. Self-coherent optical transport systems
( Xiang Liu, Sethumadhavan Chandrasekhar, and
Andreas Leven)As stated above, coherent detection transmission systems were investigated in the 1980s for their improved receiver sensitivity and selectivity, and for the promise of possible postdetection dispersion compensation. However, the emergence of EDFAs and amplified WDM systems relegated the technically difficult coherent technology to the background. Now, as high-speed signal processing technology becomes technically and economically feasible, there is renewed interest in studying coherent and self- coherent systems, especially for their capability to increase spectral efficiency through the use of advanced multilevel modulation techniques and, more important, for the possibility of implementing postdetection equalization functionalities.
Self-coherent systems utilize differential direct detection that does not require a local oscillator. With high-speed analog-to-digital conversion and digital signal processing, both phase and amplitude of the received optical field can be recon- structed, thus offering unprecedented capability for implementing adaptive equaliza- tion of transmission impairments. This chapter is a comprehensive and in-depth treatment of self-coherent transmission systems, including theoretical considerations, receiver technologies, modulation formats, adaptive equalization techniques, and applications for capacity upgrades and cost reduction in future optical networks.
1.4.5 Chapter 5. High-bit-rate ETDM transmission systems ( Karsten Schuh and Eugen Lach)
Historically, it has been observed that the first cost of a (single-channel) transmis-
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observation has prompted the telecom industry to develop higher-speed systems for upgrading transport capacity. Indeed, there is a relentless drive to explore higher speed for multichannel amplified WDM transmission where, for a given speed of operation, the total system cost is roughly proportional to the number of channels plus a fixed cost. It is important to note that the cost of equalizing for signal impairment at higher speeds must be taken into account.