涡旋光束携带的轨道角动量可以传递给粒子实现对粒子的微操控, 利用轨道角动量可以对信息进行编码实现自由空间光通信, 因而涡旋光的传输特性成为了近年来的研究热点。根据ABCD光学矩阵原理对双涡旋光束的光强表达式进行了推导, 利用MATLAB软件对内外环拓扑荷值为整数且保持不变的双涡旋光束传输特性进行了仿真研究。实验结果表明, 传输过程中光斑中心的暗核能够完整地保留下来, 且不会影响涡旋光束的轨道角动量。这表明双涡旋光束在传输过程中具有稳定性, 适用于自由空间的光学通信系统。

The orbital angular momentum of vortex beams can be used to realize micromanipulation of the particles. It can also encode the particles to realize free space optical communication. Because of its wide potential applications, the characteristics of vortex beams have become a hot topic in recent years.In this paper, the propagation characteristic of integer order double-vortex beam is studied. The propagation expression of double-vortex beam is derived by using ABCD optical matrix firstly. Then under the condition of same topological charges, the evolution of double-vortex beam spotwith transmission distanceis observed by MATLAB software. The simulation results show that the spotcharacteristics of double-vortex beam can be preserved after propagation without affecting the orbital angular. It shows that the double-vortex beam is stable in the process of transmission, which is suitable for free-space optical communication system.