以经过圆形孔径截断的 Bessel涡旋光束和Bessel-Gauss涡旋光束为例,数值模拟了近似无衍射涡旋光束在湍流大气中传输时引起的光束扩展和畸变光场中相位奇点的变化。仿真结果表明,与Bessel涡旋光束相比,Bessel-Gauss涡旋光束由大气湍流引起的束宽扩展较小,且在一定条件下其相位奇点代数和与入射涡旋光束的拓扑荷数保持一致;在远距离传输时,Bessel-Gauss涡旋光束相位奇点代数和的起伏偏差远小于Bessel涡旋光束。 Bessel-Gauss涡旋光束在自由空间光通信中作为信息载体具有较大的优势。

Taking the Bessel and Bessel-Gauss vortex beams shaped by a circular aperture as examples, beam spreading and phase singularities' behavior of approximate non-diffracting vortex beams in turbulent atmosphere are numerically simulated. The simulation results show that, the spreading of Bessel-Gauss vortex beam caused by the atmospheric turbulence is less than that of the Bessel vortex beam, and the algebraic sum of the phase singularities of Bessel-Gauss vortex beams remains close to the topological charges of the input vortex beams. In addition, the algebraic sum fluctuation deviation of the phase singularities of Bessel-Gauss vortex beams is smaller than that of Bessel vortex beams in long distance propagation. As the information carrier, Bessel-Gauss vortex beams have potential application in free space optical communication.