Reviewing the development of optical fibre lasers and amplifiers over the past few years, this book is a compilation of chapters written by several contributors. Chapter 1 presents an overview and an historical introduction to the field. Chapter 2 is theoretical and introduces the concepts of energy levels and of lasing. Chapter 3 then discusses the fabrication of rare-earth doped optical fibres whilst chapter 4 covers the spectroscopy of rare-earth dopants in these fibres. Chapter 5 emphasizes the practical aspects of the laser amplifier. Chapter 6 moves on to the operation of erbium amplifiers in optical systems and a comparison is made here with other alternatives amplifying devices. Chapter 7 reviews work on fibre laser oscillators made in silica fibre, while chapter 8 covers similar work using fluoride glass fibres, an alternative glass host. Chapter 9 describes Q-switching and mode-locking in fibre lasers, and finally chapter 10 examines future prospects for these devices and discusses potential developments such as distributed fibre amplifiers, soliton propagation and the general use of fibre lasers in optical sensors.