特殊关联部分相干光束传输与紧聚焦特性的理论研究

发布时间：2018-01-03 08:44

本文关键词：特殊关联部分相干光束传输与紧聚焦特性的理论研究　出处：《中国科学技术大学》2016年博士论文　论文类型：学位论文

【摘要】：激光束因具有方向性强、单色性好、高相干性和高能量等优点,因而在激光通信、成像以及光学捕获等领域有着重要的实际应用。但在某些方面,部分相干光束比完全相干光束表现出独特的优越性,因而受到众多学者的广泛关注。在过去的几十年里,人们对部分相干光束的研究大多数都是基于传统的高斯谢尔模关联函数,其空间关联结构满足高斯函数分布。但部分相干光束的空间关联结构不仅只是局限于高斯函数的分布形式,可以通过一定的手段来对其空间关联结构进行调控,使其具有特殊的空间关联结构分布。自Gori等人提出了构建具有特殊关联空间结构的部分相干光束的充分条件,一系列特殊关联空间结构的部分相干光束的理论模型相继被提出并于实验上产生。由于其独特的空间结构相干特性,该类特殊关联部分相干光束表现出新颖的传输和聚焦特性。近年来,具有非传统关联结构的部分相干光束在各种介质中传输与聚焦特性引起众多学者的广泛关注。本论文主要是研究此类特殊关联部分相干光束在大气湍流和晶体介质中的传输特性,以及在通过高数值孔径透镜后的紧聚焦特性和对微粒的捕获力。本论文主要内容包括：第一章首先介绍了部分相干光束的研究背景和基本理论,再引入具有特殊关联空间结构的部分相干光束的构建基本理论、研究现状和研究意义,简要概况了本论文的研究思路和研究内容。第二章基于拓展惠更斯ˇ菲涅尔原理和魏格纳分布函数的二阶矩理论,理论推导出余弦高斯关联谢尔模(CGSM)光束在non-Kolmogorov湍流中传输因子的解析表达式,具体分析了不同光束参数和湍流参数对方均根角宽发散和归一化传输因子的影响,并与传统部分相干光束的传输特性进行比较,探求改善光束传输性能和减小湍流负效应的方法。第三章基于傍轴矢量传输理论,推导出正交余弦高斯谢尔模(OCGSM)光束在各向异性单轴晶体中垂直于光轴传输的解析表达式,数值计算并分析了OCGSM光束在单轴晶体中传输时其光强、偏振度和相干度的分布情况,并与传统的部分相干光束在单轴晶体中的传输特性进行比较。最后分析了不同光束参数和晶体折射率比对传输特性的影响。第四章基于Richards-Wolf矢量衍射理论,研究了拉盖尔ˇ高斯关联谢尔模(LGCSM)光束通过高数值孔径透镜系统后的紧聚焦特性,具体分析了LGCSM光束在焦平面处的聚焦光强,偏振度和相干度分布,比较此类具有特殊关联空间结构的部分相干光束与传统部分相干光束的紧聚焦特性不同之处,详细分析了光束各参量对聚焦特性的影响。第五章基于Richards-Wolf矢量衍射理论,主要研究了径向偏振窄宽环形光束通过高数孔径透镜后的紧聚焦特性及其对微粒的辐射力。提出了一种改善捕获效率的新型且简便的方法,将一块圆形挡板巧妙地放置在聚焦透镜前,当一束径向偏振光束经过圆形挡板时形成径向偏振窄宽环形光束,在紧聚焦条件下可以形成更小的聚焦光斑和更长的焦深。在捕获微粒时,通过适当调节圆形挡板的半径改变光束的环形因子,可以增强横向上的光阱刚度和拓宽轴向的捕获范围。第六章是通过利用张量方法,理论推导了部分相干空心光束通过ABCD光学系统的传输解析式,研究了部分相干空心光束的聚焦特性及其对瑞利电介质粒子的辐射力,详细讨论了不同的光束参数对辐射力和光阱刚度的影响,以及有效捕获粒子的稳定条件。第七章是对我的研究工作进行总结与展望。
[Abstract]:The laser beam with strong directivity, good monochromaticity, has the advantages of high coherence and high energy, so in laser communication, imaging and optical trapping and other fields have important practical applications. But in some respects, partially coherent beams than fully coherent beams exhibit a unique superiority, which attracted widespread attention of many scholars in the past few decades, the research of coherent beam on the part of most people are the traditional Gauss Schell model correlation function based on the spatial correlation structure satisfies Gauss distribution function. But the spatial correlation of partially coherent light beams distribution structure is not confined to the Gauss function, through some means to control the spatial correlation structure, which has a special structure of the distribution of spatial association. Since Gori et al. Proposed construction has special relevance of spatial structure of the partially coherent light beam filling strip A series of special relevance, the spatial structure of the theoretical model of the coherent beam have been proposed and experimentally generated. Because of its unique characteristics of coherent spatial structure, the special relationship between the partially coherent beams exhibit propagation and focusing properties of the novel. In recent years, with the non beam transmission in a variety of media and traditional focusing characteristics the relational structure of partially coherent attracted extensive attention of many scholars. This thesis is propagating in atmospheric turbulence and crystal medium of such special relevance and tight focusing properties of partially coherent, in the high numerical aperture lens and on particle trapping force. The main contents of this paper include: the first chapter introduces partially coherent light beam research background and basic theory, then introduce construction has special relevance spatial structure of the partially coherent beams, the basic theory, research status A brief overview and the research significance, the research ideas and research content. The second chapter is based on the two order moment theory, Finel and Wegener extended Huygens principle of distribution function, derived from the theory of cosine Association Gauss Schell model (CGSM) analytical expressions for the propagation factor in non-Kolmogorov turbulence in the beam, analyzes the effect of different beam parameters and the other parameters are the root width of turbulent divergence and normalized transmission factor, and compared with the traditional transmission characteristics of partially coherent beams, the method seeks to improve the performance of beam transmission and reduce the negative effects of turbulence. In the third chapter, based on the paraxial vectorial theory, derived orthogonal cosine Gauss Schell model (OCGSM) beam in vertical analytic expression the anisotropic uniaxial crystal to the optical transmission, numerical calculation and analysis of the OCGSM beam propagating in uniaxial crystal when the intensity, degree of polarization and coherence The distribution of degree, and the traditional propagation properties of partially coherent beams in uniaxial crystals were compared. Finally, analyzed the influence of different beam parameters and the crystal refractive index ratio transmission characteristics. The fourth chapter is based on the Richards-Wolf vector diffraction theory, the study of Gauss, Laguerre correlation Schell model (LGCSM) beams through tight focusing properties the numerical aperture of the lens system, detailed analysis of the focusing intensity of LGCSM beam in the focal plane of the coherent polarization degree and degree distribution, compared with special relevance such spatial structure of partially coherent beams with the traditional partial dry tight focusing properties of beams are different, the effects of the parameters on the beam focusing characteristics are analyzed in detail. The fifth chapter is based on the Richards-Wolf vector diffraction theory, mainly studies the radially polarized narrow wide annular beam through the tight focusing properties of high aperture lens and the micro particle after The radiation force is proposed. The new method for improving the trapping efficiency and simple, a circular baffle cleverly placed on the focusing lens, when a beam of radially polarized beam through a circular baffle formed radially polarized narrow wide annular beam, under tight focusing conditions can form a small focal spot and long focal deep. In capturing particles, by adjusting the radius of circular baffle ring beam change factor, can enhance the lateral stiffness of the optical trap and widen axial capture range. The sixth chapter is by using the tensor method, the theory of partially coherent beams propagating through a hollow analytical formula of ABCD optical system is derived, on the focusing properties partially coherent hollow beam and radiation force of Rayleigh dielectric particles, the influence of different parameters on the beam radiation and optical trap stiffness is discussed in detail, and the effective capture particle stability The seventh chapter is a summary and Prospect of my research work.

【学位授予单位】：中国科学技术大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：O436

【相似文献】