| 斜程大气传输部分相干平顶光束的空间相干度 |
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| 引用本文： | 仓吉,张逸新.斜程大气传输部分相干平顶光束的空间相干度[J].激光技术,2009,33(5):518-521. |
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| 作者姓名： | 仓吉 张逸新 |
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| 作者单位： | 1.江南大学 理学院 无锡 214122 |
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| 摘 要： | 为了研究不同天顶角、传输距离、光源相干性以及湍流外尺度对接收面光束空间相干度的影响,采用广义惠更斯-菲涅耳原理和相位结构函数的平方近似,并运用张量积分的方法,得到了部分相干平顶光束通过斜程湍流大气传输后接收面光束空间相干度的解析表达式。结果表明,传输距离较短时,该光束空间相干度随两点距离的增加出现振荡现象,而传输距离较长时振荡现象消失;当传输距离给定时,天顶角越大,光束空间相干度的有效宽度相对较短。初始相干长度较短的该类光束其空间相干度的宽度不随传输距离的增加而减小;长距离传输后,光束空间相干性与光束初始相干长度不再有关。
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| 关 键 词： | 大气与海洋光学 部分相干平顶光束 空间相干性 斜程传输 |
| 收稿时间： | 2008-07-28 |
| 修稿时间： | 2008-11-03 |
Change in the spatial degree of coherence of partially coherent flattened beam in the slant atmosphere |
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| Abstract: | Based on the extended Huygens-Fresnel principle and the quadratic approximation of phase structure function, we have derived the analyticl expression of the spatial degree of coherence for partially coherent flattened beams propagating through the slant turbulent atmosphere with the help of tensor integral, then analyzed the effects of different zenith angle, propagation distance, coherence of source and outer scale of turbulence on the spatial degree of coherence on the receiver. Results show that the spatial degree of coherence of the beam appears the oscillating behavior with the increase of distance between two observed points for shorter propagation distance in slant atmosphere and the oscillating phenomenon disappears for longer propagation distance. When the propagation distance is fixed, the width of spatial degree of coherence is shorter for larger zenith angle. In the slant atmosphere, for the beams with shorter initial coherent length, the width of spatial degree of coherence dosen’t become shorter with the increase of propagation distance. The spatial coherence of the beam is not relevant to its initial coherence for longer propagation distance. |
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| Keywords: | Partially coherent flattened beam turbulent atmosphere spatial coherence slant propagation |
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