The revised and updated fourth edition of a successful, clearly written Modern Spectroscopy introduces the reader to a wide range of spectroscopies and includes both the background theory and applications to structure determination and chemical analysis. It covers rotational, vibrational, electronic, photoelectron and Auger spectroscopy, as well as EXAFS, and the theory of lasers and laser spectroscopy. New material includes laser detection and ranging (LIDAR), cavity ring-down spectroscopy, femtosecond lasers, femtosecond spectroscopy and very high resolution fluorescence of large molecules. In addition, the clarity of figures has been greatly improved and Professor Ben van der Veken at the University of Antwerp has run some new infrared spectra especially for this new edition.