阶变折射率轴棱锥产生局域空心光束

提出利用折射率成阶跃性变化的轴棱锥产生局域空心光束(bottlebeam).讨论了折射率沿径向成阶跃式减小或增加两种模型,从几何光学角度分析了它们产生bottle beam的原理,利用衍射积分理论数值模拟两种轴棱锥光传输的光场分布和不同距离处的二维光斑图,研究结果表明折射率沿径向阶跃减小的轴棱锥产生单个bottle beam,而折射率沿径向阶跃增加的轴棱锥产生具有周期再现的bottle beams.bottle beam在原子引导和囚禁、光学俘获及光镊等方面有广泛的应用,因此本文的研究对bottlebeam的产生和实际应用具有指导意义.

A bottle beam generated by a step refractive index axicon

Step refractive index axicon for generating bottle beam is proposed for the first time, and the two kinds of models-refractive index step-increase or decrease in radial direction are discussed. The principle of the bottle beam generation is analyzed by geometrical optics. The optical field distribution and 2D light spot image at different propagation distance behind the two kinds of axicons are numerically simulated using the diffraction integral theory. Research result shows that the step-decrease refractive index axicon generates single bottle beam, and the step-increase refractive index axicon generates periodic bottle beams. Bottle beam has a wild application in atom guiding and trapping,optical capture and optical tweezers. Research results in this paper give the significant guidance for the practical applications of the bottle beam.