像散对轴棱锥衍射特性的影响与修正

光束斜入射到轴棱锥上引起的像散将导致其衍射光场发生畸变，由衍射理论出发推导了受像散影响的轴棱锥衍射光场表达式. 通过模拟不同像散的衍射光斑图和同一像散影响下随轴向距离变化的光强分布图，分析了轴外像散对轴棱锥衍射特性的影响. 提出修正像散的方法并通过实验验证利用可调精密旋转轴棱锥修正轴外像散导致的光束畸变，理论分析和实验结果相符合,研究结果使轴棱锥的应用更加广泛. 关键词： 像散 贝塞尔光 轴棱锥 光束畸变

Influence of astigmatism on the diffraction property of the axicon and its correction

The diffraction field will show aberration if an axicon has astigmatism for beams incident at an angle. In this paper, the diffractional optical field expression of an axicon with astigmatism was derived based on the diffraction integral theory. The influence of the astigmatism on the diffraction property of the axicon was analyzed through the numerical simulation of the diffraction pattern with different astigmatism and the optical intensity distribution along the propagation direction for a given astigmatism. The method of correcting the beam aberration caused by the astigmatism is proposed and realized by the experiment using a precise tunable rotator. Experimental results agree with the theoretical analysis. The result extends the field of applications of the axicon.