Jacques Lucas is a member of the French Academy of Sciences and Emeritus Professor at the University of Rennes, France. He has co-authored several books on glasses, ceramics, and optics. He has been involved in rare earths research (photonics) as well as teaching for more than 40 years. He published more than 450 articles and co-chaired several international conferences devoted to rare earths doped optical materials. He founded and headed the CNRS Glass and Ceramic laboratory at University of Rennes for 30 years. Three start-up companies were founded based on the laboratory discoveries. He has also been Associate professor at University of Arizona and invited Professor at Kyoto University, Japan as well as at Shanghai University, PR China. He is in close contact with Solvay, the world leading company in rare earth separation, as well as with the Chinese and Japanese rare earth scientific community.Pierre Lucas is a Professor of Materials Science and Engineering at the University of Arizona, Tucson, USA. He has led several funded research projects on rare-earth doped luminescent glasses. He has been temporarily employed as an analytical chemist at Rhodia's rare-earth refining plant in France. He is author of more than 60 peer-reviewed journal articles and book chapters in solid state physics and chemistry.Thierry Le Mercier is Head of the Functional Inorganic Materials Lab, Solvay, France. He specialises in solid state chemistry and optical properties of inorganic materials. He has been working for Solvay (previously Rhodia), a world-leading company in rare earths since 1998. He is currently the head of research and development department focused on new inorganic materials and breakthrough developments for energy applications and sustainable resources. He has been developing new rare earths phosphor materials for lighting and display systems. He is author of more than 30 patents is this field.Alain Rollat has been working in the rare earths industry (Rhône-Poulenc, Rhodia and Solvay) for more than 30 years, both in the Aubervilliers Research Center and in the La Rochelle plant. During this period, he has developed several processes in the field of rare earths separation and purification (12 patents) and participated in the design and start-up of new production units of rare earths in France and China. He is currently Technology Development Manager in charge of new processes implementation for the 5 plants of Solvay Rare Earth Systems, a Business Unit of Solvay group. He is also in charge of new rare earths sourcing for Solvay, and in this capacity, he has been working over the last 5 years with the main rare earths mining projects around the world.