LD侧面泵浦变热传导系数Nd:YAG晶体温场特性研究

Temperature Filed Characteristics Analysis of Nd:YAG Crystal with Variable Thermal-conductivity Coefficient by LD Side-pumped

为了解决LD侧面泵浦Nd:YAG晶体的热效应问题,建立了前后侧面、左右端面绝热、上下侧面恒温的Nd:YAG晶体热模型。考虑到Nd:YAG晶体热传导系数是随温度变化的函数,利用解析方法与Newton切线法相结合的方法对热传导方程进行求解,得到了LD侧面泵浦Nd:YAG晶体变热传导系数情况下温度场的一般表达式。定量计算了泵浦光功率、光斑半径对温度场分布的影响。研究结果表明:在将Nd:YAG晶体的热传导系数视为定值14W·m-1·K-1时,使用50W LD侧面中心入射Nd:YAG晶体时(掺Nd3+质量分数1.0%),晶体泵浦面的最大温升为164.689℃;而将热传导系数视为随温度变化的函数时,晶体泵浦面的最大温升为268.931℃。研究结果为正确计算Nd:YAG晶体温度场分布提供了方法,并为合理设计谐振腔提供了理论依据。

In order to solve thermal effect of Nd: YAG crystal by LD side-pumped,a thermal analysis model of Nd: YAG crystal with adiabatic before and after the side or end faces fixed boundary temperature is established. In view of the Nd: YAG crystal the function of temperature that thermal transfer coefficient,application of analytic and Newton tangent method is solved to the thermal model of heat conduction equations. Geting the variable of the thermal transfer coefficient is obtained by solving the equation of the side-pumped Nd: YAG crystal of the temperature field,While quantitative calculation effect of pump power and pump spot size in temperature field distribution. Results show that,when the constant value of thermal conductivity coefficient is 14 W·m-1·K-1,the output power of LD center-side-pumped Nd: YAG crystal( The crystal has 1. 0% neodymium-doped concentration) is 50 W,the Nd: YAG crystal pumped-faces maximum temperature of 164. 689℃; when the thermal transfer coefficient as a function with temperature change,the pumped-faces maximum temperature of 268. 931℃. The results can provide the correct calculation method of the temperature distribution of Nd: YAG and reasonably designing thermally stabilized cavity of solid-stated laser.