本文提出了产生自成像局域空心光束(self-imaged bottle beams)的一种光学元件——液体轴棱锥.从衍射理论结合几何光学对经过轴棱锥后的光场进行了分析,得出注入液体折射率小于轴棱锥材料折射率时可产生自成像局域空心光束.并通过软件MathCAD模拟,得到一个完整周期光束的变换过程和局域空心光束的演变过程.研究发现液体轴棱锥产生的自成像局域空心光束具有周期及相干长度可调的特点.分析了如何利用自成像局域空心光束对粒子进行俘获,讨论了用自成像局域空心光束进行多层面粒子俘获的优势.
We propose an novel optical element-liquid axicon-to generate self-imaged bottle beams in this paper. From the diffraction theory combined with geometrical optics the light field behind the liquid axicon is analyzed, and the result shows that when the refractive index of infused liquid is smaller than that of the axicon material, it can produce self-imaged optical bottle beams. Through simulation with software MathCAD, we obtain the conversion process of a complete self-imaged optical bottle beam cycle and the evolution process of the bottle beam. We find that the coherent length of self-imaged bottle beams generated by liquid axicon is adjustable. In this paper, we analyze how to use self-imaged bottle beams to capture the particles, and the advantages of capturing multilayer particles using self-imaged bottle beams are also discussed.