涡旋光束在水下湍流中传输的闪烁因子的实验研究

Experimental Study on Scintillation Index of Vortex Beam Propagation in Underwater Turbulence

为了研究涡旋光束和高斯光束在水下湍流中的闪烁特性,搭建了一套含有水下湍流的实验系统,利用循环泵控制水槽内湍流的强弱,使用闪烁仪测量光束的闪烁因子.利用这套实验系统,详细研究了涡旋光束和高斯光束在水下传输时的闪烁因子.研究结果表明,涡旋光束和高斯光束的闪烁因子随着传输距离的增大而增大,并且随着水下湍流强度增大,涡旋光束和高斯光束对应的闪烁因子也越大.在12.6 m的传播距离内,拓扑电荷m=2的涡旋光束的闪烁因子远大于高斯光束的闪烁因子.另外,在不同强度的水下湍流中,拓扑荷数m=6的涡旋光束传播到5.4 m时,其径向闪烁因子都先减小然后再增大.此外,拓扑荷数m=6的涡旋光束经过一定距离的传播后,其闪烁因子低于拓扑荷数m=4的涡旋光束的闪烁因子.本文研究结果对探索涡旋光束在海洋湍流中的应用具有重要价值.

In order to study the scintillation characteristics of vortex beam and Gaussian beam in underwater turbulence,an experimental system consisting of water turbulence have been set up.In the water tank,the intensity of turbulence is controlled by using a circulating pump,and the scintillation index of the beam is measured by using a scintilloscope.Using this experimental system,the scintillation index of vortex beams and Gaussian beams propagating in underwater turbulence are investigated in detail.It is found that the scintillation indices of vortex beams and Gaussian beams are getting bigger with the increasing of the transmission distance,as well as with the increase of the intensity of underwater turbulence.Within the propagation distance 12.6 meters,the scintillation index of vortex beam with topological charge m=2 is much bigger than that of Gaussian beam.At 5.4 meters,the radial scintillation index of vortex beam with m=6 decreases firstly and then increases in underwater turbulence.In addition,the scintillation index of a topological vortex beam with topological charge m=6 is lower than that of a topological vortex beam with topological charge m=4 after a certain distance of propagation.The research results obtained by our experiments have important value in exploring the application of vortex beam in oceanic turbulence.