【摘要】 针对脉冲激光二极管端面泵浦Nd:YAG圆棒晶体产生的热效应问题,考虑到导热系数与温度的函数关系,建立了端面绝热、周边恒温的晶体热模型,运用解析方法计算出Nd:YAG圆棒晶体温场分布。通过对激光晶体工作特点的分析,引入弦截法,得到变热传导系数Nd:YAG圆棒晶体的温场分布表达式。不仅定量分析了在不同脉冲宽度和光斑半径下Nd:YAG圆棒晶体内部温场时变情况,而且也计算了非稳态及准热平衡态时Nd:YAG圆棒晶体的温度场。计算结果表明,使用输出功率为60 W,脉冲频率为100Hz,脉宽为2ms的三阶超高斯光泵浦Nd:YAG圆棒晶体端面,则尺寸为φ4×8mm3的Nd:YAG的圆棒晶体在达到准热平衡状态时,晶体内部最高温和最低温分别为369.1K和340.5K。研究结果为如何减小激光晶体热效应提供了一定的参考价值。更多还原

【Abstract】 In order to study the thermal effect of Nd:YAG crystal end-pumped by pulse LD,the crystal thermal model was built under the condition of model of thermal isolation of the end face and constant peripheral temperature,furthmore,the distribution of temperature field of Nd:YAG rod crystal was studied by analytical methods,considering the function relation between the coefficient of thermal conductivity and temperature.By the analysis of the characteristics of the laser crystal work,the distribution of temperature field of Nd:YAG rod crystal of variable thermal-conductivity was obtained by secant method.The internal temperature field distribution of Nd:YAG rod crystal of variable thermal-conductivity was calculated not only in different pulse width and radius of light but also in unsteady and thermal dynamic equilibrium.The results show that the transient maximum and minimum temperature of Nd:YAG rod crystal are 369.1Kand 340.5Kwhen the crystal,whose size isφ4$8mm3,reaches thermal equilibrium state.And in that case,using the third order super-Gaussian light,whose output power is60 Wand pulse frequency is 100 Hz and pulse width is 2ms,pumps the end face of crystal.The results provides a certain reference value for the study about how to reduce the laser crystal thermal effect.更多还原