部分相干平顶光束在非Kolmogorov湍流中的湍流距离

给出了部分相干平顶光束通过非Kolmogorov湍流传输的湍流距离解析表达式,并研究了非Kolmogorov湍流的湍流广义指数、内尺度、外尺度和光束参数对部分相干平顶光束湍流距离的影响。研究表明:湍流距离随相干参数、束腰、外尺度(当湍流广义指数的取值为3.6~4.0时)的增大而减小;随光束阶数、内尺度的增大而增大;随湍流广义指数先减小后增大,且在湍流广义指数取3.11时存在极小值,即光束扩展的极大值。同时利用湍流广义指数及光束参数,具体比较了湍流距离与瑞利区间的大小,并指出光束参数及湍流广义指数决定了湍流是否在瑞利区间内就能对光束扩展构成明显的影响。

Turbulence distance of partially coherent flat-topped beams in non-Kolmogorov turbulence

The expressions for the turbulence distance of partially coherent Flat-topped beams propagating through non-Kolmogorov turbulence is derived, and the influence of generalized exponent parameter of the atmospheric power spectrum, inner scale, outer scale and the beam parameters on the turbulence distance is studied. It is shown that turbulence distance decreases with increasing coherence parameter, waist width and outer scale (for generalized exponent parameter of the atmospheric power spectrum in the range of 3.6-4.0), but increases with increasing beam orders and inner scale. However, turbulence distance does not monotonically vary with the increase of generalized exponent parameter of the atmospheric power spectrum, it decreases firstly and then increases. When the value of generalized exponent parameter of the atmospheric power spectrum is 3.11, turbulence distance reaches its minima, which means that the spreading of beams is the largest. The turbulence distance and Rayleigh range are compared by using generalized exponent parameter of the atmospheric power spectrum and the beam parameters, and it shows that whether the spreading is affected by turbulence within Rayleigh range is determined by generalized exponent parameter of the atmospheric power spectrum and the beam parameters. Key words: