大气通信中部分相干径向偏振光束的束宽展宽和角扩展研究  

Width and Angular Spreading of Partially Coherent Radially Polarized Beam in Atmospheric Communication

作　　者：陈顺意[1] 丁攀峰(指导)[1] 蒲继雄[1] 

机构地区：[1]华侨大学信息科学与工程学院,福建省光传输与变换重点实验室,福建厦门361021

出　　处：《激光与光电子学进展》2015年第8期69-75,共7页Laser & Optoelectronics Progress

基　　金：国家自然科学基金(61307001、61178015);福建省自然科学基金(2013J05094、2014J05007)

摘　　要：根据广义惠更斯-菲涅耳原理及交叉谱密度矩阵推导出部分相干径向偏振光束及高斯光束在大气通信中二阶矩束宽的解析表达式,同时通过对比大气湍流强度、相干长度及光源波长对两种光束在大气通信中束宽展宽及角扩展的影响,说明部分相干径向偏振光束在大气通信中更具优越性。研究表明,部分相干径向偏振光束及高斯光束在大气湍流中的传输都满足如下规律:大气湍流强度越大,则束宽展宽越大,角扩展越大;光源相干长度越大,则光束受大气湍流的影响越大,角扩展越小;光源波长越长,光束受大气湍流的影响越小,角扩展越大。但大气湍流强度、光源相干长度及波长三方面对部分相干径向偏振光束束宽展宽的影响远小于其对高斯光束束宽展宽的影响,即同一参数下,高斯光束束宽展宽远大于部分相干径向偏振光束束宽展宽。此外,高斯光束的角扩展不仅与上述三参量有关,还受其光束束腰宽度影响,而光束的束腰宽度对部分相干径向偏振光束的角扩展并不产生影响。以上结论表明部分相干径向偏振光束相对于高斯光束更有利于在大气湍流中传输,同时关于大气湍流强度、光源相干长度及波长三参量的研究,对于部分相干径向偏振光束在大气光通信中的应用具有指导作用。Based on the theory of generalized Huygens-Fresnel and the cross-spectral density matrix, the analytic expressions of mean-squared beam width of partially coherent radially polarized （PCRP） beam and Gaussian Schell- mode （GSM） beam in atmospheric communication are derived. By comparing the influence of turbulence ,coherence length and source wavelength on the spreading of width and angular between the two kinds of beams, it shows that the PCRP beam has superiority in atmospheric communication than GSM beam.The result shows that the propagations of the PCRP beam and the GSM beam in turbulence follow the same rules. The larger the turbulence is, the larger the spreading of width and angular is. The larger the coherence length is, then the more the effect of turbulence on the PCRP beam is, the smaller the angular spreading is. The larger the source wavelength is, then the less the effect of turbulence on the PCRP beam is, the larger the angular spreading is. But the PCRP beam is far less affected by turbulence, coherence length and source wavelength than the GSM beam,which means the spreading of width of the GSM beam is larger than that of the PCRP beam. In addition, the spreading of angular of the GSM beam not only relates to the three parameters above, but also is affected by the width of the source beam which is nothing to do with the spreading of angular of the PCRP beam. The above conclusions show that the PCRP beam is more beneficial to atmospheric communication than the GSM beam, and the study about turbulence, coherence length and source wavelength has a guiding role for the application of PCRP beam in atmospheric communication.

关 键 词：大气通信 束宽展宽及角扩展 二阶矩束宽 径向偏振光束 

分 类 号：O436.1[机械工程—光学工程]