射频激励CO,2激光器的流道设计与反射镜变形分析.pdf

华中科技大学
硕士学位论文
射频激励CO<,2>激光器的流道设计与反射镜变形分析
姓名:张焱
申请学位级别:硕士
专业:物理电子学
指导教师:唐霞辉
20090501
华中科技大学硕士学位论文
摘要
本文旨在研究射频激励扩散冷却CO2激光器平板电极的冷却水流道和反射镜镜面
曲率变化的补偿。通过对电极和反射镜进行仿真模拟,分析设计了一种合理有效的电
极冷却水流道;采用温度补偿的方法,修正了反射镜的热变形。
论文的主要内容包括:
(1) 针对射频激励扩散冷却CO2激光器电极的结构和热环境,对其进行了热平衡分
析计算,研究了电极的热工作环境及其与环境之间的热交换情况,并论述了电极温度
场分析的有限元原理。
(2) 设计了 U 形、S 形、蛇形和改进的蛇形等四种电极的冷却水流道方案,然后
通过仿真各种方案下电极的温度场分布并进行比较,得知最理想的流道方案为改进的
蛇形方案。采用该方案的冷却水流道时,电极的散热效果良好,整个电极的平均温度
约为 28℃,最大温差约为 8℃,证明该种冷却水流道的设计是可取的,满足电极散热
的要求。
(3) 针对反射镜的热变形问题,论述了热变形分析的机理和有限元法。采用数值仿
真模拟的方法,求出反射镜热变形导致的镜面曲率半径的变化值为毫米级,并分析了
镜面曲率变化对激光输出光束质量的影响。而后进行了温度补偿分析,通过温度补偿,
将反射镜镜面曲率半径的变化值降低了一个数量级,证明了温度补偿能够将镜面曲率
半径的变化修正至光腔参数允许的范围之内。
本文通过对射频激励扩散冷却CO2激光器的平板电极的温度场和反射镜的热变形
进行仿真研究,为研制优质、高效的大功率激光器提供了依据。




关键词:射频激励CO2激光器平板电极反射镜温度场热变形数值仿真

I
华中科技大学硕士学位论文
Abstract
The thesis aims to study the cooling water flow channel of the slab electrode, and the
deformation pensation of the reflector for RF-excited diffusion-cooled CO2 laser.
Through simulating the electrode and reflector of RF-excited CO2 laser, an optimum flow
channel of the electrode has been analyzed and designed. By using temperature
compensation, the thermal deformation of the reflector has been corrected.
The main content includes the following aspects:
(1) According to the structure and thermal environment of the electrode, the
electrode’s heat transfer has been calculated and analyzed, and the finite element theory of
temperature field has been discussed.
(2) U-shaped、s-shaped、snake-shaped and improved snake-shaped projects for flow
channel of the slab electrode have been designed. Then the temperature fields of the
electrode have been simulated. paring the results, the improved snake-like-shaped
project has been proved to be the optimum flow channel. When using this kind of flow
channel, the radiating effect was excellent, the average temperature of the whole electrode
was 28℃, and the cooling requirement of the elec