Spectroscopy of dielectric nanocrystals doped by rare-earth and transition-metal ions

This paper reviews studies on the optical properties of dielectric nanocrystals doped by rare-earth and transition-metal ions. Manifestations of small nanocrystal size in the optical properties of impurity ions are considered. Two types of phenomena are discussed: (i) those associated with modification of the vibrational spectrum of small particles and (ii) those due to the interaction of impurity ions with the medium in which they are embedded.