Er3+/Yb3+ co-doped lead germanate glasses for up-conversion luminescence temperature sensors

Er3+/Yb3+ co-doped lead germanate glasses have been examined for up-conversion luminescence temperature sensors. Up-conversion luminescence spectra corresponding to 2H11/2 → 4I15/2 and 4S3/2 → 4I15/2 transitions of Er3+ are changed with temperature. The fluorescence intensity ratio (FIR) and temperature sensitivity were determined. The maximum sensitivity is found to be 70 × 10−4 K−1 at T = 550 K in the temperature range of 300-600 K. It suggests that Er3+/Yb3+ co-doped lead germanate glass is promising for optical temperature sensors.