Spectroscopic Properties of Rare Earths in Optical Materials Aimed at researchers and graduate students this book provides up to date information about the electronic interactions that impact the optical properties of rare earth ions in solids. Its goal is to establish a connection between fundamental principles and the materials properties of rare earth activated luminescent and laser optical materials. The theoretical survey and introduction to spectroscopic properties covers electronic energy level structure intensities of optical transitions ion phonon interactions line broadening and energy transfer and up conversion. An important aspect of the book lies in its deep and detailed discussions of materials properties and the potential of new applications such as optical storage information processing nanophotonics and molecular probes that have been identified in recent experimental studies. This volume will be a valuable reference book on advanced topics of rare earth spectroscopy and materials science.