推导出被光阑衍射高阶贝塞尔-高斯脉冲光束的场和光强分布的解析公式,对其相位奇点的演化特性做了计算和分析。结果表明,高阶贝塞尔-高斯脉冲光束经光阑衍射后,中心光涡旋始终存在,拓扑电荷守恒。随脉冲频率和脉冲宽度增加,等相位线均沿逆时针方向旋转,涡旋核随脉冲频率增加而减小,而脉冲宽度对涡旋核大小几乎无影响。等相位线随截断参数和传输距离的增加分别沿逆时针和顺时针方向旋转,涡旋核大小随截断参数增加而变化,随传输距离和光束阶数的增加而增大。

The analytical expressions of the field and intensity distributions of higher-order Bessel-Gaussian pulsed beams diffracted by an aperture have been derived,which enables us to study the evolution of the phase singularities of the diffracted higher-order Bessel-Gaussian pulsed beams. It is shown that there always exists an optical vortex at the center of the beams and the topological charge is conserved. The phase contours rotate anti clockwise about the z-axis with the increasing pulse frequency and duration. The size of the vortex core decreases with the increasing pulse frequency,but is almost unaffected by pulse duration. The phase contours rotate anti clockwise and clockwise about the z-axis with the increasing truncation parameter and propagation distance respectively. The size of the vortex core varies with the increasing truncation parameter,and increases with the increasing propagation distance and beam order.