Optical-path-difference of propagated distorted wavefront is computed.It is confirmed that transform of beam wavefront is accelerated as beam passing through the vortex with low density.

• 计算受干扰波阵面的光程差以及抖动角，确定通过涡的低密度区后会加速波阵面的变形，单体涡对光束有散焦作用。