携带轨道角动量(OAM)的分数阶涡旋光束是一种特殊螺旋结构的光束.利用空间光调制器加载传输方向与z轴夹角α干涉光栅,制备出了分数阶涡旋光束；利用水平与垂直叠加光栅,制备出具有不同拓扑荷数的光斑阵列.通过对比多组叠加实验图样,分析了不同拓扑荷数叠加涡旋光束轨道角动量序列的规律,发现分数阶涡旋光束作为载体加载信息时,较整数阶涡旋光束有更强的光强分布,其中不同分数阶涡旋光束阵列的轨道角动量序列传递信息效率较高,有利于信息的传输,为涡旋光束在自由空间通信中的复用奠定了理论基础和提供了实验依据.

Fractional vortex that carrys the orbital angular momentum is a kind of special vortex with spiral structure.Grating interference,which is made by vortex beams and the plane wave of the angle α with z axis,is used to make fractional vortex through spatial light modulator.Horizontal and vertical superposition grating is used to make the vortex arrays with different topological charge number.Through comparing the superposition of multiple sets of experimental design,the topological charge number vortex beam under the different topological superposition is analyzed.It is found that,as a carrier,the loading information fractional vortex beam is stronger than the integer vortex beam intensity,in which different fractional number,the maximum number of types of the transmission of information lays the theoretical foundation and provides the experimental basis for the reuse of vortex beam in free space communication.