【摘要】 从能量透过率导出计算非线性吸收系数的理论公式,强调了探测光束脉冲波形在计算中的作用.用高功率磷酸盐钕玻璃激光系统对掺钕浓度为1.2wt%的样品棒进行了实验测量,结果为γ=1.2cm/TW.研究了非线性吸收对放大系统增益和激光脉冲的波形所引起的变化.定量计算表明,它的影响是显著的,例如,一个TW量级的大型激光系统,γ=1.2cm/TW和2.0cm/TW时,其总增益比γ=0时分别下降18.7%和27%,输出激光脉宽增大14%和23%.更多还原

【Abstract】 A rigorous formula for the calculation of the nonlinear absorption coefficient from the laser energy transmissivity was derived. Particular attention was paid to the role of the probe pulse shape playing in the calculation. A sample of glass rod with 1.2wt% Nd2O3 doping concentration was measured with a high power Nd:phosphate glass laser system. The nonlinear absorption coefficient γ= 1.2 cm TW was obtained. Furthermore, the variation of gain and laser pulse shape in the amplifier system, caused by the nonlinear absorption, was studied. The numerical calculation shows that the effect of nonlinear absorption is important. Namely, for a large laser system capable of TW order output, the total gain in case of γ= 1.2 and 2.0 cm TW will be 18.7% and 27% less than in case of γ= 0; also the output pulse duration will increase 14% and 23% more correspondingly.更多还原