Infrared to visible upconversion luminescence in Er3+/Yb3+ doped titanate glass prepared by containerless processing

► Er3+/Yb3+ doped bulk titanate glasses were prepared by containerless method. ► Strong visible emissions were observed upon both 980 and 808 nm excitations. ► Upconversion emission mechanisms are found to be two-photon processes. ► Upconversion efficiency is enhanced by increasing the ZrO2 concentration.