使用离焦望远镜系统合成轴上平顶光束的一种新方法

提出了用平顶多高斯光束作为理想光束和使用离焦望远镜系统合成轴上平顶光束的一种新方法.在近轴近似下，基于柯林斯衍射积分公式推导出轴上光场和入射光场的解析表达式，并做了物理分析.光束阶数N，平顶长度参数L，平顶中心位置z_c和纵向中心空间频率S_c对轴上光强分布的影响用数值计算例做了说明.比较表明，该方法优于文献中使用矩形函数模拟理想光束合成轴上平顶光束的方法. 关键词： 轴上平顶光束 平顶多高斯光束 离焦望远镜系统 傅里叶变换

A new synthesis method for synthesizing on-axis flat-topped beams by using a defocusing telescope system

A new method for synthesizing on-axis flat-topped beams by using a defocusing telescope system is proposed, where the flat-topped multi-Gaussian beam is chosen as the ideal beam. Within the framework of the paraxial approximation and based on the Collins diffraction integral formula, the analytical expressions for the on-axis field and incident field are derived and analyzed physically. The effect of beam order N, flat-top length parameter L, position of the flat-top centre z_c and central longitudinal spatial frequency S_c on the on-axis intensity distribution is illustrated by numerical examples. A comparison of our results with the method for simulating the ideal beam by use of the rectangular function shows the advantages of our method.