This book is a self-contained collection of scholarly papers targeting an audience of practicing researchers, academics, PhD students, and other scientists. This book describes the rapidly developing field of fiber laser technology filling the very important role of providing students, researchers, and technology managers with valuable, timely, and unbiased information on the subject. The objective of this book is to highlight recent progress and trends in fiber laser technology covering a wide range of topics, such as self-pulsing phenomena in high-power continuous wave (CW) Yb-doped fiber lasers, Q-switched fiber laser, mode-locked fiber laser using carbon nanotubes (CNT), properties of double-scale pulses in mode-locked fiber laser, Brillouin fiber laser, dual-wave length fiber laser (DWFL) for microwave (MHz) and terahertz (THz) radiation generation, tunable fiber laser based on twin core optical fiber, reflective semiconductor optical amplifier (RSOA)-based fiber laser, dissipative soliton phenomena in fiber lasers, noiselike pulses (NLPs) in Yb-doped fiber laser, ultra fast fiber laser, numerical simulation in Q-switched and mode-locked fiber laser, gain saturation in optical fiber laser amplifiers, heat generation and removal in fiber lasers, and different fiber laser based technologies for material processing. We hope that this book will be useful for students, researchers, and professionals, who work with fiber lasers. This book will also serve as an interesting and valuable reference that will impact, stimulate, and promote further advances in the area of fiber lasers