A discussion of the theories, operating characteristics, and current technology of main fiber laser and amplifier devices based on rare-earth-doped silica and fluorozirconate fibers. It describes the principles, designs, and properties of the erbium-doped fiber amplifier and its role as the cornerstone component in optical communication systems. This second edition contains new and revised material reflecting major developments in academia and industry. "Praise for the first edition. . . . . .unreservedly recommend[ed]. It is written by acknowledged experts in the field covering everything from basic physics to system applications. Each chapter can be read independently and in application to a postgraduate or final year undergraduate teaching course this is a bonus. There is something in the text for everyone including the expert. . ..thoroughly recommend that anyone with the slightest interest in fiber lasers or amplifiers have this book readily to hand. "---Contemporary Physics ". . .sufficiently exhaustive to serve as a source of reference for experienced practitioners. . ..recommend this volume not only for personal use, but also to all libraries in universities and companies."---Optik "The book is suitable for beginners. . ..serve[s] as an excellent reference tool for experienced workers in the field."---Rare-earth Information Center (RIC)