Remarkably sustained advances in the development of new lasers and their applications in spectroscopy have prompted this revised and expanded edition of the highly successful Introduction to Laser Spectroscopy, first published in 1995. In the new edition the editors have preserved the basic concept and structure, with the involvement of some new authors - all recognized experts in laser spectroscopy. Each chapter addresses a different technique, providing a review and analysis of the current status, and reporting some of the latest achievements. With the key formulas and methods detailed in many sections, this text represents a practicable handbook of its subject. It will be a valuable tool both for specialists to keep abreast of developments and for newcomers to the field needing an accessible introduction to specific methods of laser spectroscopy - and also as a resource for primary references. The first two chapters lay out the technical details of the main laser systems now employed for spectroscopy, and then the principles and applications of absorption and fluorescence measurements. Following a description of Raman scattering, the development of pump-probe techniques is then traced. The next chapters deal more specifically with applications of laser-induced fluorescence, first addressing diagnostics for biochemical systems, and then applications to ordered systems. The use of tunable infrared lasers for the spectroscopy of transient species is discussed in the next chapter, followed by an introduction to optical nonlinearity focusing on its surface applications. The utilisation of nonlinear optics for tunable ultraviolet generation is then described and the penultimate chapter gives a description of femtosecond laser ionisation applied in mass spectrometry. The book concludes with a survey of the environmental applications of laser remote sensing.