PRE’17, is the seventh event in the series of International Workshops covering a wide range of research topics concerning the properties and applications of rare-earth ions in optoelectronics and photonics. PRE Workshops aim at providing a forum for material scientists, chemists and physicists where to debate about the state of the art and the perspectives of the photonic materials based on rare earth ions. Both fundamental photoluminescence properties and application oriented material investigations are considered. Topics of interest include (but are not limited to): • Fundamental photoluminescence properties & spectroscopic measurements • Modeling, first-principles calculations • Photonic devices exploiting rare-earths characteristics • Rare-earth-doped crystalline materials • Transparent ceramics and glass-ceramic materials • Rare-earth optical amplifiers for telecommunication • Fiber lasers and micro-chip lasers • Phosphor materials for solid-state lighting • Persistent phosphors • Scintillators • Up- and down-conversion for photovoltaic applications • Rare-earth-doped materials for biological applications