圆艾里高斯涡旋光在各向异性非Kolmogorov湍流大气中的传输

Propagation of Ring Airy Gaussian Vortex Beams in Anisotropic Non-Kolmogorov Turbulence Atmosphere

采用非均匀采样与功率谱反演法产生与湍流尺度相关的各向异性非Kolmogorov湍流随机相位屏,进而利用空间光调制器模拟研究圆艾里高斯涡旋光束在大气湍流中的漂移特性和轨道角动量态变化。数值模拟和光学实验结果均表明,圆艾里高斯涡旋光束的漂移值随光束衰减系数、光束主半径、大气湍流外尺度和传输距离的增大而增大,随湍流各向异性系数和光束拓扑荷值的增大而减小,并且在湍流幂律值为3.3附近有极大值。此外,通过对比圆艾里高斯涡旋光束经过大气湍流前后的干涉条纹图样,发现整数阶时拓扑荷值越小,光束经过湍流之后拓扑荷值稳定性就越好。

The random phase screens in anisotropic non-Kolmogorov turbulence are generated by the non-uniform sampling and power spectral inversion method, and the spatial optical modulator is adopted to simulate the drift characteristics and the changes of the orbital angular momentum of ring Airy Gaussian vortex beams in atmospheric turbulence. Numerical simulation and optical experiment results show that the drift values of ring Airy Gaussian vortex beams increase with the increasing beam attenuation coefficients, radius of the primary ring, outer scale of the atmospheric turbulence, and transmission distance, and decrease with the increasing turbulent anisotropic coefficients and topological charge of the beams. There exists a maximum drift value near the turbulent power-law value of 3.3. Moreover, comparing the interference fringe patterns of ring Airy Gaussian bortex beams before and after propagating through the atmospheric turbulence, we find that the smaller the topological charge is, the better the stability of topological charge after beam propagating in the turbulence is.