自加速Airy相关光场的构建与传输特性研究

发布时间：2018-04-03 07:17

  本文选题：自加速Airy光束　切入点：光束漂移　出处：《苏州大学》2016年博士论文

【摘要】：在不考虑衍射扩散及相对论效应的情况下,人们普遍认为激光束在自由空间中都是沿直线传播。2007年,美国物理学家D.N.Christodoulides等提出了自加速激光束的概念,用来描述沿弯曲路径传播的光束。他们产生了在实验室范围内沿弯曲路径传播的一类新型激光束,称为自加速Airy激光束。该光束具有三大奇异的特性:(1)在传输过程中保持局域光场结构不变;(2)具有自我修复的功能;(3)在传播时能横向加速,可以绕过障碍物。这些特性使其在光学清扫、弯曲等离子体通道的产生、时空光子弹、电子加速、微粒操控、全光路由和成像等领域有重要应用。另一方面,由于激光技术的发展,激光光束在光学系统以及湍流大气中的传输和变换特性已经成为激光应用研究中的重要课题。因此,新型激光光束的出现促使人们迫切地去研究它的传输变换特性,从而为其应用提供理论支持。本论文主要研究自加速Airy相关光场的构建及其传输特性,论文提出了几种与Airy光束相关的光场模型并对其传输特性进行了探讨,讨论了Airy光束在湍流大气传输过程中的漂移特点并提出了有效降低其漂移的几种方案,最后在提出光束经障碍物传输后自愈合能力量化标准的基础上详细比较了自加速Airy光束与无衍射贝塞尔高斯光束的自愈合能力。在第一章中介绍了自加速Airy光束的产生、特性、应用及其传输特性的研究背景,同时介绍了本论文的主要研究内容和创新点。在第二章中介绍了激光传输的基本理论和Airy函数相关的数学理论。在第三章中,提出了和Airy光束相关的几种光场结构的理论模型,并且研究了这些光束的传输特性。首先,为解决Airy-Hermite-Gaussian激光模积分发散的问题,提出了有限能量的Airy-Hermite-Gaussian激光束模式,可以用来描述激光束通过弯曲波导结构后的光场,澄清了以前文献中的观点;其次,双Airy光束因可方便操控其会聚焦点而在等离子热点的控制等方面备受关注,但以前的研究一直直接从现象入手,没有合适的理论模型,论文提出了简洁而有效的数学模型,为研究其特性提供了方便;再次,目前由于受限于空间光调制器,实验产生Airy光束均为小功率,论文用高斯光束合成Airy光束并讨论了其在湍流大气中的传输特性,为产生大功率的Airy光束提供了新思路,为其在大气通信中的应用打下了基础;最后,失调对激光束在精密光学系统中的传输影响很大,论文讨论了自加速Airy光束通过失调光学系统的传输特性。在第四章中,研究了自加速Airy光束经过湍流大气传输后的光束漂移问题。论文另辟蹊径,探讨光束漂移和表示光束平滑特性的K参数之间的关系,发现无论Airy光束的特征尺度及波长、传输距离、湍流的内尺度如何变化,Airy光束的漂移均在K=4.3时达到最大值。同时,发现降低Airy光束的相干性和加载涡旋位相可以有效降低Airy光束的漂移。论文还发现阵列的Airy光束比单个Airy光束以及相同阵列的高斯光束的漂移要明显减小。这些结果为实际Airy光束在大气通信中的应用提供了一些理论依据。在第五章中,量化研究了自加速Airy光束通过障碍物传输后的自愈合能力。无衍射激光束一般都有较强的自愈合能力。但是,以前的研究都是从传输后的形状上大致判断其自愈合能力,标准不很明确。论文对光束自愈合能力的量化描述提出了探索性的思考,并借助数学上描述希尔伯特空间中两个矢量相似的数学工具来定量的比较不同光束的自愈合能力。由于无衍射贝塞尔高斯光束和自加速Airy光束是非常典型的结构光场,因此,详细研究了自加速Airy光束和无衍射贝塞尔-高斯光束的自愈合能力,发现在一定范围内,自加速Airy光束的自愈合能力比无衍射贝塞尔-高斯光束强。在第六章中我们进行了总结和展望。
[Abstract]:Without considering the diffraction diffusion and the relativity effect, people generally think that the laser beam in free space are spread along the straight line.2007, American physicist D.N.Christodoulides proposed the concept of self acceleration of the laser beam is used to describe the beam along the curved path of transmission. They produced in the laboratory range along the curved path a new type of laser beam, called self accelerating Airy laser beam. The beam has three properties: (1) the singular constant local light field structure in the transmission process; (2) with self repair function; (3) can spread in the lateral acceleration, can bypass the obstacles. These characteristics make in the optical clearing, bending of the plasma channel, spatiotemporal optical solitons, electron acceleration, particle manipulation, all-optical routing and imaging applications. On the other hand, with the development of laser technology, laser beam in the light Study of propagation and transformation characteristics of the system and the turbulent atmosphere has become an important research subject in laser application. Therefore, the emergence of new laser beam made it urgent to study its transmission characteristics, so as to provide theoretical support for its application. This paper mainly studies the self accelerating the construction of Airy light field and transmission characteristic. This paper puts forward several related Airy beam light field model and its transmission characteristics were discussed, discussed the drift characteristics of Airy beams in a turbulent atmosphere in the transmission process and puts forward some schemes to effectively reduce the drift, based on the proposed beam through the obstacle transmission after self-healing quantitative criteria for a detailed comparison with the self-healing non diffraction Bessel Gauss beam self accelerating Airy beam. The first chapter introduces the self accelerating Airy beam generation, characteristics and its application The research background of transmission characteristics, and introduces the main research contents and innovations. The second chapter introduces the basic theory of mathematical theory and the Airy function of laser transmission. In the third chapter, puts forward several related and Airy beam light field structure theory model, and the transmission characteristics of these beams the study. First, in order to solve the divergence problem of integral Airy-Hermite-Gaussian laser, Airy-Hermite-Gaussian laser beam model is proposed with finite energy, can be used to describe the laser beam through the waveguide structure after light field, clarify the views in the literature of the past; secondly, double Airy beam can be easily manipulated for its convergence and focus on hot plasma control has attracted much attention, but previous studies have directly from the start, no suitable theoretical models, this paper proposes a simple and effective mathematical model, Provide convenience for studying its characteristics; thirdly, at present, due to the limited spatial light modulator, the Airy beam generated for small power, with the synthesis of Airy and the Gauss beam beam in turbulent atmosphere transmission characteristics are discussed, and provides a new idea for the Airy beam from high power, for its application in atmospheric communication lay the foundation; finally, a great imbalance on the transmission effect of laser beam on the precision of optical system, this paper discusses the self accelerating Airy beam passing through a misaligned optical system characteristics. In the fourth chapter, the self accelerating Airy light beam through atmospheric turbulence after the beam drift problem. This is another way to explore the relationship between the beam drift and said beam smoothing characteristics of K parameters, found that the Airy beam characteristic scale and wavelength, transmission distance, how to scale turbulence changes, Airy beam drift in K =4.3 reached the maximum. At the same time, Airy were found to reduce the coherence of the beam and load the vortex phase can effectively reduce the Airy beam drift. The paper also found that Airy beam array to decrease than single Airy beam and Gauss beam drift the same array. These results provided some theoretical basis for the practical application of Airy beam in the atmosphere communication. In the fifth chapter, quantitative research on the self accelerating Airy beam through the self-healing obstacle after transmission ability. Without diffraction of a laser beam have strong self-healing ability. However, previous studies are from the transmission after the shape estimate the self healing ability, the standard is not very clear the paper on the beam. Quantitative self-healing description is proposed to explore thinking, and with the mathematical description of mathematical tools in Hilbert space two vector similar to the quantitative comparison of different light Beam self-healing ability. Due to the diffraction free Bessel Gauss beam and self accelerating Airy beam is very typical of the structure of the light field, therefore, a detailed study of the self accelerating Airy beam and the diffraction free Bessel - Gauss beam self-healing ability, to a certain extent, self healing Airy beam ability than non diffraction Bessel - Gauss beam. In the sixth chapter, we summarized and discussed.

【学位授予单位】：苏州大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：TN24
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本文编号：1704166