激光大气传输相位不连续点的时空演化特征的数值计算

Numerical computation of temporal and spatial variation of branch points in laser propagation through atmosphere

利用激光大气传输4维程序对激光大气传输相位不连续点的时空演化特征进行了数值计算。仿真计算了相位不连续点随光波传输的产生和湮灭过程,以及某一固定传输位置处,畸变光场内的相位不连续点随时间的变化情况。计算结果表明,相位不连续点是随着波前运动的,并且可以成对地产生或湮灭;当传输路径中的某一位置固定时,垂直于传播方向的畸变光场内的相位不连续点所在的位置随时间的变化是不确定的,但在传输条件一定的情况下,该位置处的相位不连续点数目的统计平均值是可以确定的。

The temporal and spatial variation of branch points was computed by four-dimension code of laser propagating in atmosphere. The branch points originating and annihilating were emulated. The evolvement of branch points in some propagating range with time was emulated, too. The computational results indicate that branch points are moving along with the movement of a light wave in the space, and they originate and annihilate in pairs. The position of branch points of distorted optical field varies with time when the propagating range is fixed. When the condition of laser beam propagating in atmosphere is fixed, the ensemble average of branch points of distorted optical field can be definite at the fixed propagating range.