激光聚焦光学系统设计中球差对光束参数的影响

使用二阶矩和熵束宽定义，对平顶光束通过球差透镜后的光束参数，包括束宽、远场发散角和光束质量因子的变化做了详细研究。结果表明：球差使像方光束参数与理想情况不同；束宽和远场发散角的相对误差随球差系数绝对值的增加和光束阶数的减小而增加；球差使平顶光束通过透镜后的光束质量因子增大；实际焦面上束腰宽度的相对误差与球差系数的正负有关，而几何焦面上束宽的相对误差与球差系数的正负无关。

Influence of spherical aberration on beam parameters in design of laser optical focusing systems

Using the second-order-moment and entropy-based definitions of the beam width, changes of the beam parameters including beam width, far-field divergence angle and beam quality factor of flat-topped beams passing through a spherically aberrated lens are studied. It is shown that the spherical aberration affects the beam parameters in the image space. The relative errors of the beam width and far-field divergence angle introduced by the spherical aberration increase with increasing spherical aberration coefficient and decreasing beam order. The spherical aberration results in an increase of the beam quality factor of flat-topped beams. The relative errors of the waist width at the real focal plane depend on the sign of the spherical aberration coefficient, whereas the relative errors of the