TE矢量高斯光束的二阶矩传输  

Second Order Moment Propagation of TE Vector Gaussian Beam

作　　者：周国泉[1,2] 王绍民 

机构地区：[1]浙江大学物理系 [2]浙江林学院信息物理系,浙江临安311300

出　　处：《中国激光》2005年第1期67-71,共5页Chinese Journal of Lasers

基　　金：国家自然科学基金(60276035);浙江林学院科研发展基金(69178);浙江省教育厅科研基金(20030571)资助项目

摘　　要：运用光束传输的非傍轴矢量矩理论,对TE矢量高斯光束的传输进行了研究,给出了束腰、横向发散角和光 束传输因子的积分表达式。基于能流二阶矩定义的横向光束宽度在传输过程中服从简单的双曲线变化规律。数 值计算表明,在高度非傍轴情形下,由于TE偏振导致两个横向存在不同的光束传输特性,且最大的横向发散度超 过了非傍轴标量高斯光束的发散度极限63.43°,接近于90°,这与波动光学理论相符合,其中x方向上的发散度略 比y方向上的大。而对于傍轴情形,在非傍轴标量高斯光束傍轴化条件下,TE矢量高斯光束的传输可简化为横基 模傍轴标量高斯光束,稍有区别的是其光束传输因子始终保持略大于1,且永远不能精确地等于1。Based on the nonparaxial vectorial moment theory of light beam propagation, the propagation of TE (transverse electric) vector Gaussian beam has been investigated, and the integral expressions of beam waist, transversal divergence angle and beam propagation factor have been presented. The results reveal that both the transversal beam widths defined as second order moment of energy flux follow a very simple hyperbolic law upon propagation. The numerical calculations show that TE polarization results in different propagating characteristic in the two transversal directions for highly nonparaxial case, and the maximum transverse divergences exceed the divergence angle limit of nonparaxial scalar Gaussian beam 63.43° and are close to 90°, which is in accordant with the theory of wave optics. Moreover, the divergence in the x direction is slightly larger than that in the y direction. Under paraxial condition of nonparaxial scalar Gaussian beam, the propagation of TE vector Gaussian beam is reduced to that of transversal fundamental mode paraxial scalar Gaussian beam for paraxial case. However, the beam propagation factor will always be greater than unity and cannot accurately equal to unity forever.

关 键 词：激光光学 矢量高斯光束 光束传输 非傍轴 二阶矩 

分 类 号：O436[机械工程—光学工程]