部分相干平顶光束在非Kolmogorov大气湍流中湍流距离的变化

Change of Turbulence Distance for Partially Coherent Flat-Topped Beams Propagating Through Non-Kolmogorov Turbulence

为了说明部分相干平顶(PCFT)光束在非Kolmogorov(非K)大气湍流中湍流距离的变化,基于广义惠更斯-菲涅耳原理和利用相对M2因子定义的湍流距离,推导出部分相干平顶光束在非K大气湍流中传输的湍流距离的解析表达式。部分相干平顶光束在非K大气湍流中的湍流距离由非K大气湍流参数即广义指数参数、湍流内外尺度和部分相干平顶光束在z=0处的初始二阶矩即光束参数(包含光束阶数、波长、相干度以及束腰宽度)决定。研究结果表明,PCFT光束在非K大气湍流中的湍流距离随广义指数参数的增加先减小达到最小值后再增大,随部分相干平顶光束的阶数和波长的增加而增大,随光束相干性的减弱而增大,随光束束腰宽度的增加做先减小后增大的非单调变化。

In order to illustrate the change of turbulence distance for partially coherent flat-topped（PCFT）beams propagating through non-Kolmogorov（non-K）turbulence,based on the extended Huygens-Fresnel principle and the definition of turbulence distance using relative M2-factor,the analytical expression for turbulence distance of PCFT beams through non-Kolmogorov turbulence is derived.The turbulence distance of PCFT beams through non-Kolmogorov turbulence depends on the generalized exponent parameter,inner scale and outer scale of turbulence and the initial second order moments at the plane of z=0（namely,beam parameters including beam order,wavelength,coherence degree and beam waist width）.The results show that the turbulence distance of PCFT beams through non-Kolmogorov turbulence firstly decreases towards a minimum and then increases with the increasing of generalized exponent parameter,increases with the increasing of beam order and wavelength and decreasing of coherence property,and does not monotonously vary that the turbulence distance firstly decreases and then increases with the increasing of beam waist width.