The project joins in the development of miniaturized laser sources RGB for display and videoprojection, frequency conversion in solar cells.Fluoride glasses ZLAG ( ZrF4-LaF3-AlF3-GaF3) co-doped with rare earths were studied. This glass has a low phonon energy, a strong solubility of the rare earth ions and can be fabricated as thin films by PVD. It is also the precursor of transparent glass-ceramics. Similar emissions in both co-doped bulk and waveguides have been observed ; blue, orange, red emission for Pr3+-Yb3+ and blue, red emission for Tm3+-Yb3+. The RGB emission in bulk Tm3+-Er3+-Yb3+ tri-doped glass seems promising. Furthermore, the absorption cross section of Pr3+ and Yb3+ ions has been increased by 30% with the ceraming process.An energy transfer efficiency (ETE) of 92% has been obtained for co-doped glass with 0,5Pr3+-10Yb3+ for the conversion process of a blue photon into two infrared one.