Optical amplifiers are indispensable in long-haul communication systems operating in a relatively broad range of electromagnetic spectra. Various forms of optical amplifiers and their advancements have been extensively discussed in the literature emphasizing the relative merits and demerits of different types of configurations and/or designs and also usefulness in specific applications. The book - Optical Amplifiers: A Few Different Dimensions - aims at reporting developments in these devices in the recent years. The contributed chapters in this book encompass both theoretical and experimental results covering various aspects in the relevant research directions. This somehow makes the volume useful to both experts and novice researchers. Finally, the expectation remains of the contents to be of some merit for the R&D scientists working in universities and research institutions.