session A « Micro laser sources » [A3]International audienceWe present experimental results on a Er3+/Yb3+ doped microspherical laser. Our experiments have been focused on the 4I13/2 → 4I15/2 transition at 1550 nm of erbium ions in phosphate glass spheres. We also report on the effects that the interaction between the WGM modes of the glass sphere and an external metallic mirror has on the laser emission