【摘要】 基于广义惠更斯-菲涅耳原理和Wigner分布函数二阶矩的定义,推导出直角坐标系下大气湍流中部分相干光的M2因子传输公式。以厄米-高斯(H-G)光束为例,给出了H-G光束通过大气湍流传输后M2因子的解析表达式,并采用Tatarskii谱,详细讨论了M2因子的主要影响因素。结果表明,M2因子主要由光束的束腰宽度、波长、光束阶数、大气湍流的折射率起伏结构常数和在湍流中传输距离决定。随着光束阶数、折射率起伏结构常数及传输距离的增大,M2因子明显增大,光束阶数越高,湍流对M2因子变化的影响越小。对于给定的传输距离,存在最佳初始束宽,使M2因子最小。更多还原

【Abstract】 Based on the extended Huygens-Fresnel principle and the definition of second-order moments of the Wigner distribution function,the propagation formula for the M2-factor of Hermite-Gaussian(H-G) beams propagating in turbulent atmosphere has been derived.Taking into account the Tatarskii spectrum,major factors affecting the M2-factor of H-G beams have been discussed.The results show that the M2-factor in turbulence depends mainly on the beam order,the waist size and wavelength of the beams,the structure constant of refractive-index fluctuations of turbulence and the propagation distance.The M2-factor of H-G beams in turbulent atmosphere increases obviously as the beam order,the structure constant of refractive-index fluctuations of turbulence and the propagation distance increase,but decreases with the increasing wavelength.However,for the H-G beams with higher beam order,the effect of turbulence is less.For a certain propagation distance,there is an optimal beam waist width,at which the minimum M2-factor appears.更多还原