"The book is an indispensable reference for researchers, development engineers, and system designers in fiber-optic communications...It will excel as an introductory text in upper-level undergraduate and graduate courses on system applications of fiber optics." - "Optik". "One of the most comprehensive and detailed accounts of the physics and fundamental principles of erbium-doped fiber amplifiers...I do not hesitate to recommend the book enthusiastically to anyone having an interest in EDFAs and their applications." - "Physics Today". Erbium-doped fiber amplifiers are an important technology for lightwave voice, video, and data transmission. The first volume of "Erbium-Doped Fiber Amplifiers: Principles and Applications" offered an important exploration of the then-infant technology of erbium-doped fiber amplifiers. The passage of the 1996 Telecommunications Act and the growth of the Internet have sparked intense demand for expanded bandwidth in all network layers, resulting in significant advances in EFDA technology. "Erbium-Doped Fiber Amplifiers: Device and System Developments" brings telecommunications professionals up to date. Combining the contributions from four international experts in EDFAs, this new volume expands the reader's conceptual understanding of EDFAs and covers the developmental issues of EDFAs that are relevant to modern telecom applications. The authors review: new aspects in EDFA modeling, including the standard confined-doping, the transcendental-power-equation, and average-inversion-level models; design concepts for EDFAs in terrestrial and submarine WDM systems; transmission fiber design and dispersion-management techniques for terabit/s systems; amplified submarine-cable systems, including a brief history of submarine cable communications and the investigation of terabit/s system technologies; and advanced concepts in the physics of noise in amplified light, noise figure definitions, entropy and ultimate capacity limits. Delving into fundamental concepts (including a wealth of previously unpublished materials) as well as important breakthroughs, this much-needed resource will place telecom engineers in a position to take advantage of every aspect in the broad potential of EDFAs.