一种新型的共轴叠加复合涡旋光束

A new-type composite vortex beam generated by coaxial superposition

利用束腰半径不同、拓扑电荷数不相等的两束拉盖尔高斯涡旋光束共轴叠加,产生了一种新型的复合涡旋光束。研究了束腰半径大小对光束分布的影响以及复合涡旋光束的空间传播特性。结果表明,通过改变其中一束拉盖尔高斯涡旋光束的束腰半径可以控制复合涡旋光束的明暗花瓣与光束中心间距离;复合涡旋光束在空间传播过程中表现出衍射展宽和古伊旋转等特性。基于反射式空间光调制器(SLM)的光电实验验证了上述结果。本文研究对深入理解复合涡旋光束的形成、分布特征以及其空间传播特性等提供了一定的理论和实验依据。

A new type of composite vortex beam is generated by the coaxial superposition of two Laguerre-Gaussian vortex beams with different waist parameters and different topological charge numbers. The offects of waist parameter on the beam distribution and space propagating property of composite vortex beam are respectively investigated in this paper. It＇s found that the change of waist parameter of one Laguerre-Gaussian vortex beam can control the distance from the beam center to dark petals （low intensity positions） or bright petals （high intensity positions） on the composite vortex beam. Furthermore,diffraction broadening and Gouy rotation properties can be observed during the space propagation of the new-type composite vortex beam. The optical experiment by a reflective-type spatial light modulator （SLM） verifies the aforementioned results. The research results may provide some theoretical and experimental foundations for deep knowledge of the formation, beam distribution characteristics and space propagating property of composite vortex beams.