本文推导出了高斯列阵光束在非Kolmogorov大气湍流中传输的瑞利区间zR、湍流距离zT和远场发散角θ的解析表达式,研究了非Kolmogorov湍流的广义指数α和列阵光束的合成方式对高斯列阵光束扩展的影响.研究表明:不论相干还是非相干合成高斯列阵光束,zR,zT和θ均随着α的增加而呈非单调变化.当α=3.108时,zR和zT取极小值,而θ取极大值,即当α=3.108时高斯列阵光束扩展最厉害,光束扩展受湍流影响也最厉害.非相干合成高斯列阵光束扩展比相干合成的要大,但受非Kolmogorov湍流影响却要小.特别值得指出的是:当自由空间光束衍射较小时,有zT〈zR,即在瑞利区间范围内大气湍流就对光束扩展有影响;而当自由空间光束衍射较大时,有zT〉zR,即在瑞利区间范围内大气湍流对光束扩展几乎没有影响.
The expressions for the Rayleigh range za, the turbulence distance ZT and the far-field angle θ of Gaussian array beams propagating through non-Kolmogorov turbulence are derived. Influence of generalized exponent factor a of the atmospheric power spectrum and the type of beam combinations on the spreading of Gaussian array beams is studied. It is shown that for both coherent and incoherent combinations, the dependence of ZR, ZT and θ on a is not monotonic. When a = 3.108, za and ZT reach their minima, and θ reaches its maximum. This means that the spreading is largest, and the spreading is enormously affected by turbulence when a = 3.108. For the incoherent combination the spreading is larger than that for the coherent combination, but for the incoherent combination the spreading is less affected by turbulence than that for the coherent combination. It may be that, for the small free-space diffraction we have ZT 〈 ZR, i.e., the spreading is affected by turbulence within the Rayleigh range; for the large free-space diffraction we have ZT 〉 ZR, i.e., the spreading is less affected by the turbulence within the Rayleigh range.