近地面激光大气传输中, 由于强湍流的影响, 畸变波前中存在相位涡旋, 使得自适应光学系统校正效果下降甚至失效。通过建立近地面激光大气传输模型, 分析了不同闪烁强度下畸变波前中相位涡旋分布特性, 以及自适应光学系统校正效果。针对近地面相位涡旋不能被有效校正的问题, 分析了波前畸变被完全复原时不同单元数变形镜对含相位涡旋波前畸变的校正效果。研究表明: 采用直接斜率法的自适应光学系统只能校正畸变波前中的连续相位, 不能校正相位涡旋组成的不连续相位; 含相位涡旋的波前畸变被有效复原后, 连续表面变形镜能够校正不连续相位, 现阶段限制自适应光学系统近地面校正效果的关键因素是波前畸变能否被有效复原。

When laser beam propagates through the strong turbulent atmosphere, phase vortex existing in the distorted wavefront makes the correction of adaptive optics system decline. By establishing a near ground laser propagation model, the distribution characteristics of phase vortex under different scintillation levels and the correction of adaptive optics system were analyzed. In order to investigate the reason why the phase vortex cannot be effectively corrected, the correction result of deformable mirrors with different number of actuators is analyzed when the wavefront distortion is completely restored. Results show that the adaptive optics system using the direct slope method can only correct the continuous phase, but not the discontinuous phase composed of phase vortices. And after the wavefront distortion with phase vortices is effectively restored, the continuous surface deformable mirror can correct the discontinuous phase. At this stage, the key factor limiting the correction effect of the adaptive optics is whether the wavefront distortion can be effectively restored.