Book excerpt: This book describes advances in both experimental and theoretical treatments in the field of energy transfer processes that are relevant to various fields, such as spectroscopy, laser technology, phosphors, artificial solar energy conversion, and photobiology. It presents the principles and available techniques through specific examples. In addition, it examines current and possible applications, including the most recent developments, and projects future advances and research possibilities in the field. Contents: Fundamental Interactions Leading to Energy Transfer (B Di Bartolo); Energy Transfer Processes in Atoms and Molecules (W DemtrAder et al.); Advances in the Techniques for the Study of Energy Transfer (D Hulin); Upconversion Phenomena with Laser Applications (X Chen); New Applications of Ultrafast Spectroscopy (J M Hvam); Efficient Solid State Lasers (N P Barnes); Emission Efficiency and Energy Transfer in Color Centers at High Concentrations (G Baldacchini); Four-Wave Mixing Studies of Energy Transfer Processes (G Boulon); Upconventional Light Emissions in Rare-Earth Doped Solids (F Auzel); Photonic Molecular and Supramolecular Devices (J M Lehn); Reflections on the Theory of Everything (G Costa); Earthquakes, Measurements, and Mitigation of Seismic Risk (R Console); Site Selectivity of Defects in IIIOCoV Compounds by Local Mode Spectroscopy and Model Calculations (D N Talwar); The General Non-Radiative Energy Transfer Master Equations for Crystalline Materials, the Exact Solution and Current Modeling (L A D az-Torres et al.); and other papers. Readership: Researchers and graduate students in the fields of lasers and optics."