【作者】 王小妮；

【导师】 朱林泉； 牛晋川；

【作者基本信息】 中北大学 ， 信号与信息处理， 2008， 硕士

【摘要】 动态光学波前误差是困扰光学界几百年的老问题,自适应光学技术提供了解决这一难题的途径。随着大型激光工程和光学系统的发展,对克服动态误差的需求日益迫切,自适应光学技术已经得到长足发展,应用领域正在从军事应用、科学研究扩展到民用领域。本文研究了自适应光学在无线激光通信中的应用。但是在无线激光通信中,由于所涉及的是随机的大气信道,其中除了大气对激光信号的吸收、散射外,大气湍流还使激光信号在传输过程中产生光斑闪烁、光束漂移和光斑分裂等现象,这将严重影响无线光通信系统的稳定性和可靠性。为了减小大气湍流效应的影响,提出了采用自适应光学技术的解决方案。本文在详细介绍自适应光学技术的基础上,阐述了自适应光学技术在无线激光通信中的应用。具体内容如下:(1)概述了自适应光学技术及其国内外发展动态。由于自适应光学技术发展历史较短,在已有的文献中,对自适应光学技术的定义描述较含糊,甚至把主动光学与自适应光学混为一谈。论文对被动光学、主动光学、自适应光学的技术特征作出了明确的界定,清楚地指出了三者的联系和区别,技术发展的沿革情况。(2)系统总结了自适应光学技术在空间探测、空间光通信、星基对地望远镜、核聚变装置、高能激光武器和视网膜检测六个领域中的应用。(3)针对光学天线在接收信号时会受到杂光的影响而产生背景噪声,对卡塞格伦光学天线进行了遮光罩的设计。对主遮光罩进行设计,选择了在主遮光罩内设置径向叶片来避免遮光罩过长,此设计可有效的抑制杂光源直接照射在系统主镜上产生的一次散射杂光;对主镜和次镜设计了锥状遮光筒,可防止杂光源辐射经主遮光罩散射后,直接穿过主镜中心开孔到达探测器,从而可最大限度地遮挡杂光辐射。(4)介绍了哈特曼传感器的工作原理,分析了影响其探测精度的因素;在对可变形镜重要技术指标分析的基础上,阐述了可变形镜反射镜的研究进展及发展趋势,并介绍了用于自适应光学系统的几种新型可变形反射镜。(5)分析了大气信道对激光通信的影响,研究了采用自适应光学技术来解决因大气湍流引起的光斑闪烁、光束漂移和光斑分裂等问题。明确界定了被动光学、主动光学、自适应光学的技术特征,清楚地指出了三者的联系和区别,技术发展的沿革情况;系统总结了自适应光学技术在各个领域中的应用;设计了卡塞格伦光学天线的遮光罩,并将自适应光学应用到无线激光通信中,具有一定的创新性和实用价值。更多还原

【Abstract】 The problem of dynamic optic wavefront aberration has puzzled human for hundreds years, and adaptive optics technology proposes an approach to solve this problem. with the development of large-scale laser engineering and optical system, the demand of overcoming dynamic error is urgent. Adaptive optics is used from military, scientific research to civil domain. In this paper, adaptive optics technology is applied in wireless laser communication.However, the channel of wireless optical communication is atmosphere channel, which could absorb and scatter the optical signal. What is worse, the atmospheric turbulence could induce scintting, excursion and splitting of facula during transmission. These phenomena will badly affect the stability and reliability of the wireless optical communication. A new adaptive optics technique is proposed to reduce the effect of atmospheric turbulence.In this thesis, adaptive optics technology is introduced in detail. Based on this, the application of adaptive optics on wireless laser communication is also expatiate. The main contents are as following:(1) Elaborated adaptive optics and its domestic and international development dynamic state. Because of the short development history of adaptive optics technology, in former literature, the definition of adaptive optics was obscure description, even more active optics and adaptive optics garbled. In this paper, the characters of passive optics, active optics and adaptive optics were specific definition, and their contacts and differences and the case of its development were denoted. (2) Summarized the applications of adaptive optical technology in six fields including space exploring, space laser communication, star-ground telescope, nuclear equipment, high-power laser weapon and retina detection.(3) Because background noise will be arose when optical antennas are incepting signals, designed a baffle of cassegrain optical antenna. Designed main baffle, selected radial leaves for ultra-short baffle as the design method which could realize stray radiation suppression. Besides, coneshaped shade tubes for main mirror and second mirror to shelter from stray radiation in maximum were designed.(4) Introduced the principle of Hartmann-Shack wave-front sensor, and analyzed the main factors of influencing sensor measurement accuracy; By discussing the research progresses and development trends of deformable mirrors, expatiated the research and development trends of deformable mirrors, and introduced several novel deformable mirrors which applied in adaptive optics system.(5) Analyzed the influence of atmosphere channel to wireless laser communication, and adopted adaptive optics technology to compensate some phenomenon such as scintting, excursion and splitting of facula induced by atmospheric turbulence during transmission.Specific definition of the characters of passive optics, active optics and adaptive optics and their contacts and differences and the case of its development were denoted; summarized the applications of adaptive optical technology in six fields; designed a baffle of cassegrain optical antenna and adopted adaptive optics technology in wireless laser communication all that bear originality and practicability.更多还原