Effect of copper impurity on the optical loss and Nd3+ nonradiative energy loss of Nd-doped phosphate laser glass

N31-type phosphate laser glasses doped with different concentrations of Cu were prepared. Their optical loss coefficient at 1053 nm wavelength and nonradiative transition rate from the Nd3+4F3/2 state were determined and analyzed in detail. The optical loss coefficient per unit of Cu2+ (cm−1/ppmw) and the fluorescence decay rate (Hz/ppmw) caused by Cu2+ and Nd3+ interaction were 0.0024 and 7.9, respectively. Cu impurity affected both optical loss at 1053 nm and fluorescent emission of Nd3+4F3/2 state seriously in N31 laser glass.