摘要
准连续激光二极管(LD)泵浦的激光晶体中存在着温度升降的变化过程。为解决准连续LD端面泵浦Nd∶YAG薄片时变热效应问题,基于热传导方程,采用特征函数法和常数变异法得到了准连续超高斯光束端面泵浦Nd∶YAG薄片的瞬态温度场一般解析表达式。定量分析了准连续泵浦光脉宽和占空比对Nd∶YAG薄片瞬态温度场的影响。研究结果表明,准连续LD端面泵浦Nd∶YAG薄片时,薄片内温度场随时间呈波浪状分布,再经过一段时间后呈现出稳定周期性分布,此时的瞬态温度场围绕连续LD泵浦时稳态温度波动,波动幅度为12.1℃,薄片的瞬态温升量将随准连续LD泵浦脉宽与占空比的增大而升高。研究方法和所得结果还可以应用到激光系统的其他瞬态热问题研究中,对解决激光系统热问题具有理论指导作用。
The transient processes of temperature rise and fall exist in laser crystal pumped by quasi-CW laser diode（LD）.Based on the heat conducting equation,a general analytical transient temperature filed expression of Nd∶ YAG microchip end-pumped by the quasi-CW supper-Gaussian beam was obtained by the methods of the eigen-function and the constant variation.Meanwhile,the influence of the quasi-CW pump beam with different waist radius and pulse widths on the transient temperature filed of Nd∶ YAG microchip were quantitatively analyzed.The results show that when quasi-CW LD end-pumps the Nd∶ YAG microchip,the temperature distribution of Nd∶ YAG microchip will undulate with pump pulse.And after a period of time,the temperature field will present stable periodic distribution.The transient temperature field of microchip will undulate around the temperature field end-pumped by CW LD.The fluctuant amplitude of temperature field is 12.1 ℃.And the temperature rise of microchip increases with the pump width or duty cycle of the quasi-CW LD.The research methods and results can also be used to analyze other transient thermal problems in laser systems.
出处
《激光与红外》
CAS
CSCD
北大核心
2012年第4期377-381,共5页
Laser & Infrared
基金
西安市科技局创新支撑项目(No.CXY1015(6))
陕西省工业攻关项目(No.2008K05-15)资助
