腔内扰动对虚共焦腔模式的影响及Zernike像差拟合  

Effect of intracavity perturbation on modes of virtual confocal resonators and Zernike aberration fit

作　　者：张翔[1] 蔡青[1] 

机构地区：[1]成都信息工程学院光电技术系,成都610225

出　　处：《激光技术》2009年第6期657-660,663,共5页Laser Technology

摘　　要：为实现高功率或高能激光器输出良好的光束质量和能量,分析了腔内像差扰动对非稳腔模式的影响,采用数值迭代法理论计算了腔内倾斜扰动对无源虚共焦非稳腔输出模式强度和相位分布的影响,并采用 Zernike 模式法对光束相位进行了像差拟合分解,得到了前35阶像差系数,通过进一步计算得到点扩散函数和环围能量曲线等,从而全面了解输出光束质量。结果表明,对小菲涅耳数虚共焦型非稳腔,腔内倾斜扰动不仅带来输出光强分布的不均匀性,且对相位分布有明显的影响,使相位中的一些高阶 Zernike 像差如 A_3,A_7和 A_(10)等增大。计算结果对研究高能激光器腔内像差校正有一定参考意义。In order to improve the output beam quality and energy for high power lasers, firstly, the influence of intraeavity aberrated perturbation on the eigenmode of unstable resonators was analyzed. Then,the effect of intracavity phase-tihed perturbation on the mode intensity and phase distribution for passive positive-branch confocal unstable resonators was calculated by means of numeric iterative method. Finally ,the phase property of the output beam was analyzed based on Zernike mode-reconstruction theory so that the front 35-order Zernike aberration coefficients, the point spread function （PSF） and the integrated relative far-field intensity were obtained. Now the laser beam quality was fully illustrated. The results illustrate that in a confocal unstable resonator with a small Fresnel number, small phase-tilted perturbation has not only a remarkable influence on the output beam intensity but a/so the phase structure,and it makes higher order Zernike aberration such as A3 ,A7 and A10 increase in the beam phase structure. The results are of some reference to further investigation on the intracavity aberration compensation for high power lasers.

关 键 词：激光光学 光束质量 迭代法 虚共焦非稳腔 腔内像差扰动 Zernike像差拟合 

分 类 号：TN243[电子电信—物理电子学]