【作者】 吴慧云；

【导师】 赵伊君； 陈金宝； 许晓军；

【作者基本信息】 国防科学技术大学 ， 光学工程， 2012， 博士

【摘要】 中继镜技术是近年来备受各方瞩目的一项重要的新型激光系统作战概念，在军事上具有独特的应用背景。论文从中继镜技术的基本概念出发，围绕中继镜系统的光束传输理论、应用可行性、上行链路能量耦合效率及优化提升方法和双自适应光学装置的影响等内容，采用理论分析、数值模拟和缩比实验验证方法展开了较为系统的研究。首先，开展了中继镜系统光束传输理论和应用可行性研究。根据现有的研究资料分析了中继镜系统的结构组成，从光束传输性能角度分析了最优上行传输方式。在此基础上，分析了中继镜系统光束传输理论，详细推导了真空和湍流条件下激光中继镜传输过程的等效菲涅耳数以及靶面光斑峰值强度与传输过程等效菲涅耳数之间的关系。分析了激光中继镜传输可行的判断条件以及应用优势范围的计算方法，分别以天基激光、机载激光和地基激光中继镜系统为具体场景进行了模拟计算。在实验室条件下，以“光源波长1.064μm，望远镜口径1.2m，上行传输距离30km，下行传输距离10km”的中继镜系统为原型，以传输过程等菲涅耳数为准则，搭建了中继镜系统光束传输缩比实验装置，开展了实验研究。理论和实验结果表明：中继镜系统能提升激光对远距离目标的打击效果，拓展激光的作用范围。其次，开展了双自适应光学装置对中继镜系统性能影响的理论研究。根据中继镜系统两套自适应装置不同的工作条件和用途，结合自适应光学装置的主要类型和特点，分析了中继镜系统两套自适应装置宜选取的类型，得出：位于光源处的自适应装置宜选用共轭式自适应光学系统，位于飞行平台上的自适应装置宜选用优化式自适应光学系统。在此基础上，以“Hufnagel-Valley5/7模型湍流条件下，目标高度25km，飞行平台高度30km”的地基激光中继镜系统为模型，模拟计算了不同校正精度条件下中继镜系统的打击性能，结果显示：“闭环”理想校正时，目标靶面光斑的一倍衍射极限桶中功率比（与初始光源功率之比）为61.44％，是“开环”条件下的3.6倍。再次，开展了中继镜系统上行链路能量耦合效率分析及其优化提升方法研究。理论方面，模拟分析了中继镜系统上行链路能量损耗情况及造成能量损耗的主要原因；分析了利用光束全场整形、阵列光束相干合成和涡旋光源三种方法提升中继镜系统上行链路能量耦合效率的基本原理，模拟了上述三种方法对中继镜系统上行链路能量耦合效率的提升效果。主要结果为：“闭环”工作时，上行链路能量耦合效率为84.46％；通过光束全场整形，上行链路能量耦合效率由84.46％提升至99.73％；通过阵列光束相干合成，上行链路能量耦合效率由84.46％提升至95.02％；通过涡旋光源，上行链路能量耦合效率由84.46％提升至98.04％。实验方面，搭建了中继镜系统光束传输缩比实验装置，实验分析了中继镜系统上行链路能量损耗情况；利用液晶空间光调制器和缩比实验装置开展了光束全场整形和涡旋光源对中继镜系统上行链路能量耦合效率提升效果的实验研究。主要实验结果为：缩比中继镜系统上行链路能量耦合效率为71.89％；通过光束整形，上行链路能量耦合效率由71.89％提升至87.88％，目标靶面光斑5像素（半径32.25μm）桶中功率比由44.52％提升至52.78％；通过涡旋光源方法，上行链路能量耦合效率由71.89％提升至90.60％。最后，开展了光束控制优化方法对中继镜系统性能提升效果的理论研究。以光束整形为例，分析了光束控制优化方法对中继镜系统性能的提升效果，在H-V5/7模型湍流条件下，以“目标高度25km，飞行平台高度30km”的地基激光中继镜系统为模型，模拟计算了不同校正精度条件下，光束整形对中继镜系统上行链路能量耦合效率和系统打击性能的提升效果。论文的研究结果有望对中继镜系统的论证和设计提供一定的参考，论文提出的光束整形、阵列光束相干合成和涡旋光源三种方法可在激光空间自由通信系统等光学系统中拓展应用。更多还原

【Abstract】 The relay mirror technology is an important new laser system combat concept thathas unique application in military field, which has been under extensive research inrecent years. Begin with the basic concept, contents including theory of beampropagation in a relay mirror system, the feasibility of a relay mirror system, powercoupling efficiency of a relay mirror system and the methods used to improve uplinkpower coupling efficiency, influences induced by the two adaptive istallations areinvestigated in theory, simulation and experiment in this thesis.First, theory of beam propagation in a relay mirror system and the feasibility of arelay mirror system are investigated in theory and experiment. Based on the previousresearches on the relay mirror technology, components of a relay mirror system isanalyzed, the optimal mode of beam uplink propagation is analyzed with the emphasison the damage performance at the target. Based on the optimal mode, theory of beampropagation in a relay mirror system is analyzed, the equivalent Fresnel number of beampropagation in a relay mirror system under vacuum and turbulence conditions, therelations between the maximum beam intensity at the target and the equivalent Fresnelnumber are both ratiocinated in detail. The conditions in which a relay mirror system isfeasible is analyzed, the method used to compute the advantage scope of a relay mirrorsystem is illuminated. As examples, the advantage scopes of relay mirror systems withspace-based laser, airborne laser and ground-based laser are simulated. In the laboratory,a reduced-scale experimental installation is established with the same Fresnel number ofbeam propagation in a relay mirror system with1.064μm laser source,1.2m-diametertelescopes,30km uplink propagation distance and10km downlink propagation distance.With the experimental installation, the reduced-scale experiment is carried out. Thetheoretical results and the experimental results show that the relay mirror system canimprove the laser damage performance to the forane target and extend the laser’s range.Second, influences to the relay mirror system damage effect induced by the twoadaptive optics istallations are investigated in theory. According to the different workingconditions and different uses, styles of the two adaptive optics istallations used in arelay mirror system are analyzed with the characteristics and styles of the adaptiveoptics used in nowadays. We get that the adaptive optics istallation locates at the sourceshould use the conjugacy based adaptive optics, the adaptive optics istallation locates atthe platform should use the optimization algorithm based adaptive optics. Based on themodel of a ground-based laser relay mirror system under the Hufnagel-Valley5/7turbulent model condition and with the parameters as:25km target height and30kmplatform height, performances of the relay mirror system under different precisions ofthe adaptive optics istallations are simulated. The results show that proportion of power in bucket with diffraction limit radius is61.44％under the closed-loop and idealconditions, which is3.6times of the value under the open-loop.Then, power coupling efficiency of beam uplink propagation in a relay mirrorsystem and methods used to improve the uplink power coupling efficiency areinvestigated in theory and experiment. In theory, power coupling efficiency of beamuplink propagation in a relay mirror system is simulated, theories of three methods usedto improve the uplink power coupling efficiency including beam shaping, coherentbeams combination and vortex beams are analyzed, and performances of the abovemethods are simulated. The theoretical results show that uplink power couplingefficiency of the relay mirror system is84.46％, power coupling efficency is improvedfrom84.46％to99.73％by beam shaping; power coupling efficency is improved from84.46％to95.02％by coherent beams combination; power coupling efficency isimproved from84.46％to98.04％by using vortex source. In experiment, areduced-scale experimental installation is established, and the experiment of detectinguplink power coupling efficiency of the relay mirror system is carried out. By using twoliquid crystal spatial light modulators, the experiments of detecting uplink powercoupling efficiencies of the relay mirror system with beam shaping and vortex sourceare carried out. The experimental results show that uplink power coupling efficiency ofthe relay mirror system is71.89％, uplink power coupling efficency is improved from71.89％to87.88％, proportion of power in5pixelsbucket （32.25μm radius）isimproved from44.52％to52.78％by beam shaping; uplink power coupling efficencyis improved from71.89％to90.60％by using vortex source.At last, performances of beam control optimizations in a relay mirror system areinvestigated in theory. Taking beam shaping as an example, performances of a30km-height relay mirror system with different precisions adaptive optics istallations aresimulated under the Hufnagel-Valley5/7turbulent model.The results of this dissertation may provide some references for the design and thedevelopment of the relay mirror system, the three methods proposed in the paper thatused to improve uplink power coupling efficiency of the relay mirror system can beused in laser systems including laser communication systems, laser data transmittionsystems and so on.更多还原