Energy Level of Free Ions

Abstract

Most of the solid-state laser materials consist of insulators doped with a small amount of rare earth ion or transition-metal ion (optically active ions, which will be simply called active ions in all the discussions of this book). The spectra of all these materials have very close relationship with the energy level structure of free ion (atom) and the transition rules between these energy levels. Therefore, the basic knowledge of the atomic spectroscopy is very important for the investigation of laser materials.