轴对称偏振涡旋光束经介质面的聚焦特性毕业论文
2021-03-31 20:48:02
摘 要
本篇论文主要介绍了轴对称偏振涡旋光束经介质面的聚焦模型,并在聚焦模型的基础上探究了两种轴对称偏振涡旋光束:径向偏振和角向偏振涡旋光束的通过介质面的聚焦特性。同时本文也简单介绍了光学涡旋的研究历史,基本概念以及应用前景。光束涡旋是具有螺旋形波前的奇异光场,它具有很多与一般光场截然不同的性质。
论文主要研究了两种类型轴对称偏振涡旋光束在经过介质面时在聚焦场内的光强分布,根据光强分布在不同条件下的数值变化分析了其在经过介质面时的聚焦特性。
研究结果表明:径向偏振涡旋光束和角向偏振涡旋光束的整体光强都会随着拓扑电荷数的增大而减小,并且当拓扑电荷数ngt;1时,两种偏振涡旋光束都会在聚焦面内出现一个中心暗通道。径向偏振涡旋光束相较于角向偏振涡旋光束多出了轴向分量所以径向偏振涡旋光束在聚焦面内的整体光强要大于角向偏振涡旋光束。对于径向偏振涡旋光束而言改变介质面两边的折射率会改变其光强分布规律,而对于角向偏振涡旋光束而言改变介质面两边的折射率则只会改变其整体光强,对于光强分布规律并没有影响。
本文利用了数值分析,得出了不同条件下径向偏振涡旋光束和角向偏振涡旋光束在聚焦场内的光强分布图,并且加以对比,图文并茂的介绍了轴对称偏振涡旋光束经介质面的聚焦特性。
关键词:光学涡旋;轴对称偏振涡旋光束;聚焦特性;光强分布
Abstract
This paper mainly introduces the focusing model of the axisymmetric polarized vortex beam through the dielectric surface,and explores two kinds ofaxisymmetric polarized vortex beams on the basis of the focusing model: Radial polarization and angularly polarized vortex through the medium The focus of the face. At the same time,this paper also briefly introduces the research history,basic concepts and application prospects of optical vortex. Thebeam vortex is a singular light field with a helical wavefront,which has many properties that are distinct from the general light field.
In this paper,we study the intensity distribution of the two types of axisymmetric polarized vortex beams in the focusing field when passing through the dielectric surface. According to the numerical changes of the light intensity distribution under different conditions,the focusing characteristicsof the beam are analyzed.
The results show that the overall light intensity of the radial polarized vortex beam and the angularly polarized vortex beam decreases with the increase of the number of topological charges, and when the number of topological charges ngt;1,the two polarized vortex beams Will appear in thefocus of a center dark channel. The radial polarized vortex beam has more axial components than the angularly polarized vortex,so the radial intensity of the radially polarized vortex beam in the focal plane is greater than that of the angularly polarized vortex. For the radial polarization vortex beam to change the refractive index on both sides of the media surface will change its light intensity distribution law,and for the angular polarization vortex beam changes in the media surface on both sides of the refractive index will only change its overall light intensity,Which has no effect on the law of light intensity distribution.
In this paper,numerical analysis and simulation are used to obtain the intensity distribution of the radial polarized vortex beam and the angularly polarized vortex beam in the focusing field under different conditions,and the axial symmetric polarization vortices are introduced. Focusing characteristics of the rotating beam through the dielectric surface.
Key words: optical vortex;axisymmetric polarized vortex beam;focusing characteristic;light intensity distribution
目 录
摘要 I
Abstract II
第1章 绪论 1
1.1光学涡旋的发展历程 1
1.2涡旋光束 2
1.3光束的聚焦介绍 3
1.4 研究目标及内容安排 9
第2章 光学涡旋的基本概念及其应用前景 10
2.1光学涡旋的基本概念 10
2.2 光学涡旋的应用前景 11
2.3 本章小结 11
第3章 轴对称偏振涡旋光束聚焦原理及特性 13
3.1径向偏振涡旋光束的聚焦 13
3.2角向偏振涡旋光束的聚焦 15
3.3轴对称偏振涡旋光束经介质面的聚焦特性 15
第4章 总结与展望 26
4.1 总结 26
4.2 展望 26
参考文献 28
致谢 29
第1章 绪论
1.1光学涡旋的发展历程
早在1917年,在爱因斯坦对原子辐射的研究中就已经提出了受激辐射,并且预见了激光的产生[1]。而在爱因斯坦的研究基础上,世界上第一台红宝石激光器在1960年诞生,这宣告着光学的研究进入了一个新的历史阶段:现代光学正式的出现在了人类科学史中,现代光学一诞生便开始蓬勃发展,衍生出了很多各分支,例如量子光学、非线性光学、激光光谱学、激光材料和激光器物理学以及超强(超快)光学等等。
而对具有奇异性的光学现象研究则是近几年来学界的热点,很多与波前相位奇异性有关的效应以及具有奇异点的波前拓扑学等都是包括在其中,我们可以称具有奇异性的光场为奇异光场。和一般的光场所拥有的平滑波前相比较而言,奇异光场则具有着很多与一般光场截然不同的性质。