大气湍流尺度对部分相干光传输特性的影响

本文在考虑湍流内外尺度的情况下,对部分相干高斯谢尔模型光束在大气湍流中的传输特性进行了研究.主要采用考虑湍流内外尺度的修正Von Karmon谱模型,推导了部分相干光在大气湍流中的平均光强分布、光束扩展均方根束宽和漂移方差的解析式.对比分析了不同湍流强度情况下,湍流内外尺度对部分相干光在大气湍流中水平和斜程路径上传输特性的影响.结果表明:相同条件下,光束在大气湍流中传输时,沿斜程传输时的抗湍流能力强于水平传输;相比于大气湍流内尺度,大气湍流外尺度对光束漂移影响较大,外尺度对光束扩展与光强分布的影响较小,当湍流外尺度增大时,漂移现象会越来越严重;相比于大气湍流外尺度,湍流内尺度对光束扩展与光强分布的影响较大,当内尺度减小时,光束扩展现象越来越严重,光强分布也更分散,内尺度对漂移几乎无影响.

Effect on the Partially Coherent Beam Propagation Properties in the Atmospheric Turbulence Considering Its Scales

Propagation properties of partially coherent Gaussian-Schell model beam, under the condition of considering the atmospheric turbulence of inner-scale and outer-scale, were studied in the atmospheric turbulence.Using the model of modified Von-Karmon spectrum which considers its inner-scale and outer-scale, the expressions of intensity distribution, wander variance and beam width of partially coherent beam were deduced in the atmospheric turbulence.The influence to partially coherent beam, on the turbulence along a slant path and a horizontal path considering the inner and outer scale, were analyzed in different turbulence intensity.The results show that, under the same condition, the anti-turbulence ability of the beam propagated in the atmosphere along a slant path is more better than the horizontal path.In addition, compared with the inner scale of the atmospheric turbulence, the outer-scales of the beam propagated in the atmosphere has a greater effect on the wander variance, the outer-scales have a minor effect on the intensity distribution and beam width, when the outer-scale increasing, wander variance is more serious.Furthermore, compared with the outer scale of the atmospheric turbulence, the inner-scales has more effect on intensity distribution and beam width.When the Inner-scales reduced, the beam expanding phenomenon is becoming more and more serious.Intensity distribution is more scattered, and inner-scales of wander variance almost has no effect.