摘要
建立了激光二极管阵列(LDA)侧面泵浦棒状Nd:YAG增益介质时变热效应理论计算模型。采用有限元Ansys软件模拟分析了脉冲LDA侧面泵浦大能量固体激光器的时变热效应特性。研究结果表明,所研究的脉冲LDA侧面泵浦大能量Nd:YAG激光器热效应具有时变特性,介质横截面内中心点处的稳态温度场分布随时间呈锯齿形周期变化,锯齿形变化频率为LDA泵浦频率,脉冲LDA泵浦参数对介质稳态温度场分布有较大影响。分析和计算了介质内热梯度、应力双折射以及激光晶体端面效应等导致的晶体热透镜焦距。计算表明,介质的热焦距主要来源于介质内温度梯度引起的热透镜焦距。
In this paper, we study the thermal effects of side-pump large energy solid state laser. We set up a numerical model of LDA side pump Nd：YAG laser rod. Using Ansys program, the finite element method is adopted to analyze the time-var- ying thermal effect for pulse pump solid-state laser. The steady temperature field and the transient temperature field distribution are simulated, and the changing rule of the distribution of temperature field in the medium is summarized. We calculate the ther- mal focal length caused by thermal gradierit, stress birefringence, and the end effect of medium respectively. The research results show that the thermal effect of LDA side pump laser show time-varying characterictic, the center temperature in cross section of medium have a zigzag periodical change, and the frequency equals to LDA pump frequency. The steady-state distribution is influ- enced by LDA pump parameters greatly. The thermal lens effect is mainly caused by the temperature gradient in the medium. This study could provide a theoretical guidance for the design of thermal-stable laser resonator and compensation of thermal effect.
出处
《强激光与粒子束》
EI
CAS
CSCD
北大核心
2015年第6期24-31,共8页
High Power Laser and Particle Beams
基金
国防支撑项目
关键词
热效应
有限元法
固体激光器
时变温度分布
thermal effect finite element method solid-state laser time-varying temperature distribution
