蝴蝶光束的焦散和波前特性

Caustics and Wavefronts of Butterfly-Shaped Beams

提出并实验产生一种基于衍射突变的新型蝴蝶光束。根据突变理论,该光束的光场结构由状态变量和控制变量共同构成的势函数所决定。由于蝴蝶突变的高维性,蝴蝶光场的焦散理论上表现为4维空间的超曲面,映射该光场到低维空间,其展现丰富多样的光场结构。此外,通过操纵控制参数,发现蝴蝶光束能调控成不同的光场结构。研究了蝴蝶光束的频谱,发现其谱振幅能用多项式形式表示。所得数值模拟结果与实验结果吻合。该光束具有弯曲的传播轨迹和丰富的光场结构,在波前控制、光学微操纵与生物医学方面有潜在应用。

A novel butterfly-shaped beam based on diffraction catastrophe is proposed and experimentally generated.According to the catastrophe theory,the light field structures of the beams are defined by the potential function composed of the state and control variables.The caustics of the beams are theoretically manifested as hypersurfaces in fourdimensional space due to the high dimensionality of the control variables,and these beams display diverse light field structures when they are mapped into a low-dimensional space.Furthermore,different light field structures of the beams can be obtained by manipulating the control variables.It is found that the spectral amplitudes of the beams can be expressed as polynomials.The experimental results are in good agreement with the numerical simulation ones.These beams have excellent properties including curved propagation trajectories and various light field structures,which are likely to be applied to wavefront control,optical micromanipulation,and biomedicine.