光学学报, 2010, 30 (3): 802, 网络出版: 2010-03-11
全固态Nd:YAG激光器热效应及输出光束波前像差分析
Analysis of Thermal Effect and Experimental Test of Beam Wavefront Aberration in All Solid-State Nd:YAG Laser
激光技术 激光二极管抽运YAG激光器 热效应 Hartmann-Shack波前传感器 波前重构 Zernike像差 laser technique laser diode pumped YAG solid laser crystal thermal effect Hartmann-Shack wavefront sensor phase reconstruction Zernike aberration
摘要
高功率全固态激光器的诸多腔内扰动因素均会直接影响到激光输出功率和光束质量。首先采用传输矩阵方法简要讨论了在稳定腔情形下热透镜焦距与本征模式光斑尺寸的关系。进一步采用Hartmann-Shack波前传感器和模式法波前重构,对二极管抽运全固态声光调Q激光器输出倍频光束质量进行了分析,得到前35阶Zernike像差系数、波前峰谷值和均方根等畸变参量,计算还可得到点扩散函数分布和环围能量曲线等,从而全面了解输出光束质量和动态像差特性。分析表明输出倍频光的波前Zernike像差主要集中在前15 阶,由于晶体热效应及腔内其它扰动因素的影响,较显著波前像差有离焦系数Z3、低阶像散Z4和Z5,以及球差Z10等。
Abstract
Many factors of intracavity perturbation degrades the output power and beam quality for high power laser diode pumped solid laser. Firstly,the relation between the focal length of thermal lens and the beam spot size is analyzed by means of transmission matrix optics. Experiment on output beam quality of a LD pumped acousto-optic Q-switched laser has been also performed by adopting Hartmann-Shack wavefront sensor and mode method of wavefront reconstruction theory. Using this method,the peak-to-valey value and root mean square values of the aberration wavefront,the frontal 35-order Zernike aberrations can be acquired,and Strehl ratio curve of the output beam and the distribution of circle energy can also be obtained by calculation,so the mode properities can be fully understood. Experimental results show that the beam wavefront aberration is mainly concentrated in the frontal 15 orders of Zernike aberration,mainly including the defocus Z3,the low-order astigmatism Z4 and Z5,and the spherical aberration Z10 because of crystal thermal effect.
张翔, 苏礼坤, 蔡青. 全固态Nd:YAG激光器热效应及输出光束波前像差分析[J]. 光学学报, 2010, 30(3): 802. Zhang Xiang, Su Likun, Cai Qing. Analysis of Thermal Effect and Experimental Test of Beam Wavefront Aberration in All Solid-State Nd:YAG Laser[J]. Acta Optica Sinica, 2010, 30(3): 802.