Infrared and Millimeter Waves, Volume 1: Sources of Radiation explores modern sources of radiation available for use in the far-infrared and near-millimeter wavelength range of the spectrum. This book describes the operating principles and comparative performances of all three types of device: electron tubes, solid state devices, and optically pumped lasers. This volume is comprised of seven chapters; the first of which reviews the developments in the design and construction of high-power, high-efficiency millimeter sources and in the nonlinear theory for cyclotron masers. The second chapter deals with IMPATT devices for millimeter-wave power generation, with emphasis on device physics design considerations as well as cw and pulsed operations of IMPATT oscillators and amplifiers at millimeter frequencies. The chapters that follow focus on optically pumped lasers, backward wave oscillators, the Ledatron, and infrared and submillimeter-wave waveguides. This book concludes with a discussion on free electron lasers based on stimulated scattering from relativistic electron beams. An original reformulation of stimulated scattering theory that attempts to encompass all previous treatments is described and compared with available experimental data. This text also presents a semi-qualitative analysis of nonlinear saturation. This book will appeal to scientists and professional engineers.