像散Bessel光束自重建特性的理论和实验研究  

Theoretical and experimental study of self-reconstruction property of astigmatic Bessel beam

作　　者：杨艳飞 陈婧 吴逢铁 胡润 张惠忠 胡汉青 Yang Yan-Fei;Chen Jing;Wu Feng-Tie;Hu Run;Zhang Hui-Zhong;Hu Han-Qing(Fujian Key Laboratory of Light Propagation and Transformation,College of Information Science and Engineering,Huaqiao University,Xiamen 361021,China)

机构地区：[1]华侨大学信息科学与工程学院,福建省光传输与变换重点实验室,厦门361021

出　　处：《物理学报》2018年第22期224-233,共10页Acta Physica Sinica

基　　金：国家自然科学基金(批准号：11774103); 国家自然科学青年基金(批准号：61605049,61802136)资助的课题

摘　　要：基于菲涅耳衍射积分理论和巴比涅原理,推导出像散Bessel光束经圆形障碍物后的光强分布一般表达式.数值模拟了像散Bessel光束经圆形障碍物遮挡后光场的自重建过程,并设计相关实验进行验证,实验结果与理论模拟基本符合.结果表明:零阶像散Bessel光束经过轴上和离轴障碍物后均会发生光束重建现象.随着传输距离的增加,像散Bessel光束的外轮廓尺寸变大、中心光点阵列数增多,逐渐重建出不同于障碍物前的完整光束.并且观察到光束在重建过程中横向和纵向的重建速度并不一致,存在一定的速度差.利用螺旋相位板产生高阶像散Bessel光束,验证了高阶像散Bessel光束经障碍物遮挡后同样具有自重建特性.研究结果对像散Bessel光束在多层面粒子操纵方面的应用具有参考价值.In this paper, the self-reconstruction property of astigmatic Bessel beam is studied experimentally and theoretically.Based on the Fresnel diffraction integral theory and Babinet principle, the general expression of the intensity distribution of astigmatic Bessel beams passing through a circular obstacle is derived. The cross-section light intensity at transmission distance of, 10, 30, and 80 mm after astigmatism of the astigmatic Bessel beam are occluded by circular obstacles. The self-reconstruction process of the light field is observed and verified by using an specially designed experimental setup. In the experiment, we choose He-Ne laser as a light source, collimate and expand the beam through a telescope system, and a zero-order astigmatic Bessel beam is generated by a beam vertically incident on the tilted axicon after the diaphragm.A circular obstacle with a radius of 0.2 mm is placed at a distance of 200 mm behind the axicon. Finally, the cross-section intensities at different distances are observed and recorded by a microscope. The experimental phenomena are in good agreement with the theoretical prediction. The results show that the reconstruction of the zero-order astigmatic Bessel beams will occur after passing through the on-axis and off-axis obstacles. And as the transmission distance increases, the outer contour size of the astigmatic Bessel beam becomes larger, and the number of central spot arrays increases, and the complete beam is gradually reconstructed. Particularly, this feature is different from the behavior of the non-diffracting Bessel beam, which maintains the light field unchanged during transmission and has a single central spot. It is expected to be applied to multi-layer multi-particle control. And a new optical property is discovered in the experiments： the reconstruction speed of the beam in the horizontal and vertical direction are not consistent in the reconstruction process,and there is a certain speed difference. Further, we add a spiral phase plate between the diaphragm and

关 键 词：菲涅耳衍射 像散Bessel光束 自重建 螺旋相位板 

分 类 号：O436[机械工程—光学工程]