相全息图产生任意阶无衍射光束阵列的理论和实验

Theory and experiments of generation of arbitrary order nondiffracting beams array by phase holograms

无衍射光束由于其中心光斑尺寸小、传播中无衍射等特性被广泛关注。提出了一种相位全息图产生任意阶次和位置的无衍射光束阵列的方法。设计具有相同特征值的相全息图阵列,即阵列中每幅相全息图在频谱面上产生相同半径的亮环,并把相全息图阵列写入空间光调制器,由于傅里叶变换平移不变性,相全息图阵列在频谱面上仍产生唯一能量集中的亮环,通过环形滤波器将其滤出,再次进行傅里叶变换,便得到无衍射光束阵列,并且每个无衍射光束的位置和阶次都可以任意设置。理论分析和实验均证明了该方法的可行性。

Nondiffracting beams are of interest for optical potential applications owing to their properties of smaller central spot,longer propagation distance and so on.A phase-hologram-based method of generation of nondiffracting beams array with arbitrary order is proposed.If a phase-hologram-array that possesses the same eigenvalue is utilized,a unique bright annulus is generated in the Fourier plane because of the shift-invariance of Fourier transform and consistency of phase hologram design.Then through the Fourier transform again,a nondiffracting beams array is generated.Furthermore,the location and order of each individual nondiffracting beam can be customized according requirement.Experimental results are in good agreement with the numerical simulation and theoretical analysis.