激光在传输的过程中,光斑受到大气湍流的影响,会“破碎”成若干碎片。对发射光束取不同形状和不同光束质量时,在不同湍流强度情况下的传输进行了计算,并对碎斑特征进行统计分析。结果表明,随光束质量变差和湍流强度的增强,总光斑扩大,碎斑数目增多,占空比减小,而碎斑半径变化不大,约为真空衍射包含总能量63.2%的光桶半径。针对这一现象,从薄环光束真空衍射、双孔衍射、将光场分解为不同频率场的叠加和实心束强湍流等四种情况分别进行了讨论,给出了初步的理论分析。

The beam spot will break up into some cracks when the beam propagates through the turbulent atmosphere. The characteristic of the cracked beam spot are studied statistically for different emitting beam shapes and beam qualities, and with different turbulent effects. It is shown that, with the degeneration of the beam spot and the turbulence being stronger, the total radius of the beam spot and the number of the fragments will increase; meanwhile the radius of the fragments will keep invariable almost: about the radius of the bucket which contain 63% of the total energy. In order to understand this phenomenon, four different kind of situations: the diffraction of thin ring, diffraction of double apertures, decomposing the field into the superimposition of different frequencies and the propagation of solid beam with strong turbulent effects, are analyzed and primary explanation are given.