This book gives an overview on studies of physical, chemical and luminescent properties of pure and rare-earth doped group IV A oxide phosphors has been discussed. The oxides taken under consideration in present work is SiO2 and SnO2. SiO2 have been known for a long time as a convenient host for rare earths and have been widely used for the fabrication of solid-state lasers whereas SnO2 is a wide band gap n-type semiconductor with wide band gap of 2.5-3eV, which crystallizes in the rutile structure (tetragonal structure), SnO2 is a member of a special class of semiconductors that have direct...