Metaphosphate glasses doped with five concentrations of ${\mathrm{Er}}^{3+}$ ions have been investigated through absorption and emission spectra, decay curves, and upconversion measurements. Judd–Ofelt parameters have been evaluated from absorption spectrum of the $1.0\text{mol.}\%$ ${\mathrm{Er}}^{3+}$ -doped glass, which are in turn used to predict radiative properties of some important luminescence levels of ${\mathrm{Er}}^{3+}$ ions in these glasses. Gain bandwidths of an optical amplifier have been evaluated and are compared with those of reported ${\mathrm{Er}}^{3+}$ :glass systems. Temperature dependence of the $1.5\mathrm{\mu }\mathrm{m}$ emission has been studied for the $2.0\text{mol.}\%$ ${\mathrm{Er}}^{3+}$ -doped glass from $13\mathrm{K}$ to room temperature. Lifetimes of the ${}^{4}I_{13∕2}$ level were measured and are found to decrease with concentration of ${\mathrm{Er}}^{3+}$ ions after $0.1\text{mol.}\%$ . Concentration quenching of lifetimes has been analyzed using the theory developed by Auzel et al. [ J. Lumin. 94–95, 293 (2001) ; Opt. Mater. 24, 103 (2003) ]. Infrared to visible upconversion was also measured for three concentrations of ${\mathrm{Er}}^{3+}$ -doped metaphosphate glasses with $794\mathrm{nm}$ excitation. A mechanism, involving excited state absorption and energy transfer upconversion, has been proposed to explain the upconversion process.