This book represents the first detailed description, including both theoretical aspects and experimental methods, of the interaction of rare-earth ions with surface plasmon polariton from the point of view of collective plasmon-photon interactions via resonance modes (metal nanoparticles or nanostructure arrays) with quantum emitters (rare-earth ions). These interactions are of particular interest for applications to optical telecommunications, optical displays, and laser solid state technologies. Thus, our main goal is to give a more precise overview of the rapidly emerging field of...