Laser approaches to combustion diagnostics are of considerable interest due to their remote, non-intrusive and in-situ character, unlimited temperature capability, and potential for simultaneous temporal and spatial resolution. This book aims to make these powerful and important new tools in combustion research understandable. Focuses on spectroscopically-based, spatially-precise, laser techniques for temperature and chemical composition measurements in reacting and non-reacting flows. Following introductory chapters on basic spectroscopy, laser physics, experimental methods and practical considerations, treats each of the major techniques in some detail, replete with measurement examples and references. Concludes with a treatment of field methods which employs the various techniques to perform measurements simultaneously over a two-dimensional slice of the medium being probed.