光学涡旋在湍流大气中产生和传输机理研究

When intensity fluctuation reaches certain degree, optical field can spontaneously generate optical vortices in turbulent atmosphere, which typically called phase branch points. This is because of the dirrection of non homogeneous random medium. The genetation and evolution of the optical vortices is a new phenomenon in the domain of light propagation in turblent atmosphere.In the condition of strong turbulence, optical vortices has potential and serious impacts on the electro-optical engineering, and significantly deteriorates the performance of the technology of adaptive optics, which geneally can correct the wavefront distortions in the weak and moderate turbulent atmosphere.. Based on the phase fluctuation and phase branch points of optical field proagating in turbulent atmosphere, we will investigate the generation and evolution of optical vortices and the evolution mechanism of topological charge in turbulent atmosphere, by adopting the theoretical analysis, numerical calculation and experiment. Then intensity and phase fluctuation of partially coherent vortex beams propagating in turbulent atmosphere and its orbital angular momentum will be discussed in detail, we also want to analyse and distinguishthe the difference between the resource vortex and the vortex produced in random propagation medium。It is more difficult for accurate phase unwraping in the presence of branch points. This project will study the infulence of optical vortices to the highly accurate phase unwraping technology.How to eliminate optical vortices generated in turbulent atmosphere is also dicussed. And finally, some potential application of the optical vortex will be propesed in consideration of their propagaion dynamics.. This project will emphasize on the theoretical and experimental research of the optical vortices propagaing in turbulent atmosphere. The research result would be helpful for the high accurate detection and recoving of phase in the adaptive optical techniques and would provide important reference for the technology of space laser communication and poential application of optical vortex.

光场在大气湍流中传输时，当光强起伏达到一定程度，光场可自发产生光学涡旋，也就是通常意义上所指的相位不连续。光学涡旋在大气湍流中的产生和发展是光波大气传输中的新现象，在强湍流情况下，明显恶化自适应光学校正大气湍流引起波前畸变的效果。本课题从光场在大气湍流中传输时的相位起伏和相位不连续性出发，利用数值解析、数值模拟和实验相结合的方法研究湍流大气中光学涡旋的产生、发展以及其拓扑荷的传输机制；研究涡旋光束在大气湍流中的光强分布以及轨道角动量的传输特性，分析光源中的涡旋和传输介质产生的光学涡旋在大气湍流中传输的异同点，并加以判别；光学涡旋的存在使得相位的准确复原更难，研究光学涡旋对相位高精度复原技术的影响；研究如何消除传输介质中产生的光学涡旋，分析利用光学涡旋传播动力学特征的潜在应用。该项目的研究有助于自适应光学技术中高精度的相位探测和复原，对空间激光通讯技术以及光学涡旋的应用具有重要意义。

光学涡旋作为独特的光场在诸如光学微操控技术和信息传递领域等方面的潜在应有价值，并引起了学术界的高度关注。近年来，光学涡旋的研究已经成为一个迅速发展的光学前沿热点。涡旋光束在空间光通信领域具有巨大的应用前景，因此研究光学涡旋在大气湍流中的传输特性具有重要的实用意义。本项目围绕光涡旋在大气湍流中传输特性的研究，采用了数值解析和数值模拟相结合的研究方法，研究了矢量平顶涡旋光束，部分相干的矢量拉盖尔-高斯涡旋光束以及标量贝塞尔高斯涡旋光束和椭圆涡旋光束在湍流大气中的动态传输演变特性，详细地研究了涡旋光的拓扑特性和相干特性以及偏振特性等对涡旋光在光涡旋在大气中传输时的光谱相干特性，光谱偏振特性以及光谱强度等特性的影响，研究发现通过调控涡旋光束的参数可以调制光涡旋在大气湍流中传输时的偏振特性。全邦加球光束（FP）由于在整个横截面内都包含有所有的光的偏振态而著称，由于其偏振奇异特性越来越受到学术界的关注。本项目基于空间光调制原理，构造了具有对称偏振奇点的FP光束，深入研究了在不同背景光场下涡旋对之间的旋转和湮灭。研究还发现当在FP光束的背景光场中置入不同的光学涡旋时，FP光束的传输特性就截然不同。在本项目资助下，共在国际国内学术期刊上发表论文4篇，其中SCI3篇，EI1篇；译著一部；联合培养硕士研究生3名。在本项目资助下，共参加国际学术会议1次。邀请国外专家来访1次。项目经费使用合理，完成项目预期研究计划.