Optimization of concentration and length of laser medium in diode-end-pumped solid-state lasers considering energy-transfer-upconversion effects

The influence of energy-transfer-upconversion effects and the divergence angle of pump beam on the laser performance of diode-end-pumped solid-state lasers are investigated. Based on it, the doping concentration and length of laser medium are optimized for diode-end-pumped Nd:YVO4 laser taking into account the thermal effect with ETU effects and the intrinsic loss of laser medium. The theoretical results are rather in good agreement with the published experimental data. The theoretical prediction of optimum neodymium doping concentration and the optimum length of Nd:YVO4 crystal are 0.08% and 13 mm, respectively.