This book discusses the theories, fabrication techniques, physical properties, operating characteristics, and current technology associated with fiber laser and amplifier devices. Optical properties of rare-earth-doped glasses and rare-earth doped infrared-transmitting glass fibers are described as well as CW Silica Fiber Lasers and broadband fiber sources. Finally, Erbium-Doped Fiber Amplifiers, including basic physics, characteristics, and recent advances are discussed.