腔内像散扰动对正支共焦腔模式影响的数值分析  

Numerical analysis of mode properties for confocal unstable resonators with intracavity astigmatism-aberrated perturbation

作　　者：张翔[1] 蔡青[1] 朱兴华[1] 

机构地区：[1]成都信息工程学院光电技术系,成都610225

出　　处：《强激光与粒子束》2009年第3期345-349,共5页High Power Laser and Particle Beams

基　　金：国家高技术发展计划项目

摘　　要：针对激光器出光过程中腔内像差扰动带来的输出光束质量和光束能量下降问题,分析了腔内像差扰动对非稳腔模式的影响,并采用数值迭代法计算了理想情形和腔内像散扰动对无源正支共焦腔输出模式强度和相位分布的影响,进一步采用Zernike模式法对光束相位进行了像差拟合,得到了前35阶Zernike像差系数、点扩散函数(PSF)分布和环围能量曲线,计算了腔内像散扰动量与远场Strehl比的关系。结果表明:对小菲涅耳数正支共焦腔,腔内像散扰动对输出光束强度和相位分布均有明显影响,相位分布中一些高阶Zerni-ke像差也有所增大。因此在进行腔内像差校正时,应优先考虑此类像差的校正。For a laser resonator cavitiy using an unstable resonator configuration, experiments have proved that the intracavity perturbation is an important influencing factor for degrading the output energy and the beam quality. The influence on eigenmode properties for passive unstable resonators has been analyzed. The effect of the intracavity astigmatism-tilted perturbation on the mode properties for positive-branch confocal unstable resonators has been calculated numerically by using an iterative method. The phase structure of the output beam is analyzed by adopting the Zernike mode-reconstruction theory; and Zernike aberration coefficients of the first 35 order, integrated relative far-field intensity, and point spread function（PSF） are all obtained. These numerical results illustrate that small phase-tilted aberrations have a remarkable influence on the output beam intensity and phase properties for the unstable resonator with a small Fresnel number, and higher-order Zernike aberrations such as A3, A3 , and A10 will also increase in the beam phase structure. When beam wavefront correctors of adaptive optics are used for intracavity aberration compensation, the correction for astigmatism aberration should be performed at first.

关 键 词：信息光学 正支共焦非稳腔 腔内像差扰动 光束质量 Zernike像差特性 

分 类 号：TN243[电子电信—物理电子学]