【作者】 王贺；

【导师】 周忠祥；

【作者基本信息】 哈尔滨工业大学 ， 光学， 2012， 博士

【摘要】 随着人们对科技领域探索的深入，激光在信息通讯、军事武器、航天、生产生活等领域发挥着越来越多的作用。因为在不同领域需要应用激光的不同特性，各种各样的激光光束应运而生。而径向偏振光束具有特殊的性质，其在原子捕获、激光通信等领域引起人们的关注。本文以径向偏振光束的实际应用为背景，选取径向偏振部分相干光束（radially polarized partiallycoherent beams-RPPCBs）为研究对象，重点研究径向偏振激光光束在湍流大气、光学系统、置于湍流大气中的光学系统以及单轴晶体中这几个典型的系统中的传输特性，主要工作包括：基于相干光束在湍流大气中传输的广义惠更斯-菲涅尔公式，研究了入射到湍流大气中径向偏振部分相干光束的传输特性。研究发现在近场传输时，径向偏振部分相干光束在湍流大气中的演化特性与在自由空间(C2n=0)是相似的；大气湍流加速光束在湍流大气中传输时的发散速度；在远场处，径向偏振部分相干光束的偏振度将趋向于零，光束的束腰逐渐扩大。基于相干与偏振的统一理论，采用矩阵方式研究了径向偏振部分相干光束在ABCD光学系统中传输时的演化特性。研究发现随着传输距离的增加，在远场处，径向偏振部分相干光束的偏振度将趋向于零，而在自由空间中(A=1，B=z)传输的径向偏振部分相干光束的局域最小相干度为零，其原因为随着传输距离的增加，相干度从负值逐渐增大为正值，同时在远场处，光束也将变为完全相干。综合考虑湍流大气和ABCD光学系统，研究了径向偏振部分相干光束在大气湍流环境内的ABCD光学系统中的传输性质,并研究了湍流大气对径向偏振部分相干光束的斯托克斯参数的影响。研究发现径向偏振部分相干光束在置于湍流大气中的光学系统中传输时的演化特性与径向偏振完全相干光束(σ=xx σ=yyinf)的演化特性是类似的；研究还发现径向偏振部分相干光束经过在置于湍流大气中的ABCD光学系统中的传输后，在远场处将变为完全非相干光束。基于相干光束在单轴晶体中沿着垂直于光轴方向传输的傍轴近似公式，分析了在单轴晶体中，径向偏振部分相干光垂直光轴方向入射时的传输特性。发现光束在x轴和y轴上具有不同的发散速度，在远场处，光束的偏振度将趋向于零。研究还发现单轴晶体的折射率比值ne no对径向偏振部分相干光束的相干度影响不明显。更多还原

【Abstract】 With exploration of the field of science and technology, laser playing anincreasing role in the field of information and communications, militaryweapons, aerospace, production and living. Because of the different characterused in different applications of laser, various new laser beams have beenintroduced. Radially polarized beams have been used in atom attractor, lasercommunication etc.. Considering the application background of radiallypolarized partially coherent beams (RPPCBs), the transmission characteristicsof the RPPCBs in turbulent atmosphere, ABCD optical system and uniaxialcrystals are studied. The main results are:Based on the extended Huygens-Fresnel integral formula in turbulentatmosphere, the propagation properties of RPPCBs propagating in turbulentatmosphere are studied. It is shown that the evolution properties of RPPCBs inturbulent atmosphere are similar to that in free space (C2n=0) in the near field,the beam spreads more rapidly because of turbulent atmosphere, and the degreeof polarization will be equal to zero in the far field and the beam waist enlargegradually.The propagation properties of RPPCBs propagating in ABCD opticalsystem are studied by using cross-spectral density matrix. With the increase inpropagation distance, we can find that the degree of polarization for RPPCBswill be equal to zero in the far field, the local minimums are equal to zero whenthe beam propagating in free space (A=1，B=z), the reason is as the distanceincreases, the degree of coherence is gradually increasing from negative topositive, while the degree of coherence will become full in the far field.Considering the beam propagating in the turbulent atmosphere and ABCDoptical system, the properties of RPPCBs propagating through ABCD opticalsystem in turbulent atmosphere are studied. We find that the evolution propertiesof RPPCBs through an optical system in turbulent atmosphere are similar toradially polarized fully coherent beam (σ=xx σ=yy inf) in the near field; and thedegree of coherence for RPPCBs propagating through an optical system inturbulent atmosphere will become fully incoherent beam in the far field. Theinfluence of atmospheric turbulence on the Stokes parameters of RPPCBs is alsoanalyzed.The transmission characteristics of RPPCBs propagating in uniaxialcrystals orthogonal to the optical axis are studied. We find that the beams will spread in different speed along x-axis or y-axis, and in the far field, the degreeof polarization will be equal to zero, and the affect ofne no on the degree ofcoherent is not obvious.更多还原