• 教学讨论 •

### 非傍轴近似条件下透镜的出射光场分布

1. 1. 湖南科技学院 理学院物理系，湖南 永州425199；2. 浏阳市第六中学，湖南 长沙410324
• 收稿日期:2022-09-13 修回日期:2022-11-17 出版日期:2023-07-01 发布日期:2023-07-11
• 作者简介:邢容（1978—），男，安徽无为人，湖南科技学院讲师，博士，主要从事近代物理实验与固体物理之教学及量子光学研究工作.E-mail:xingrongbird@hotmail.com

### The emergent light field of lens without paraxial approximation

XING Rong1, LI Ai-hua1, GUO Meng-jiao2

1. 1. Department of Physics, College of Science, Hunan University of Science and Engineering, Yongzhou, Hunan 425199, China;
2. The sixth middle school of Liuyang, Changsha, Hunan 410324, China
• Received:2022-09-13 Revised:2022-11-17 Online:2023-07-01 Published:2023-07-11

Abstract:  The equations of emergent light produced by a point object located on the axis of a len are derived without considering paraxial approximation by using a ray-tracing method. Based on the equations, the distribution diagrams of emergent light field are drawn by using Geometric Sketchpad. The results obtained by analyzing the diagrams show that when the len is convex, the energy of the actual emergent light field in the initial range behind the len is mainly distributed in the zone formed by a rotation surface with a special generatrix and a spin axis which is the optical axis. The border of the zone becomes more and more blurred as the distance from the lens increases. On each cross section perpendicular to the optical axis, the actual emergent light field presents three different characteristics successively with the distance from the len increasing. When the len is concave, there is not a zone where the light intensity is greatly stronger than another zones in the emergent light field, and the energy scatters in every cross section.