大气湍流中部分相干聚焦涡旋光束的传输特性

基于广义惠更斯-菲涅耳原理和相位结构函数的平方近似,研究了部分相干高斯-谢尔模型涡旋光束被聚焦后在大气湍流中的传输特性,得到了焦平面上光强解析表达式.利用该表达式,详细研究了该类光束在大气湍流中传输焦平面上的光强分布特性.结果表明：在大气湍流中,随着传输距离的增加,涡旋光束的奇异性逐渐降低.对于拓扑荷大的以及空间相干长度较长的涡旋光束,光束奇异性的保持相对要好.在一定的焦距长度和湍流大气条件下,我们可以通过调整光源的拓扑荷和相干长度控制焦面光强分布和焦斑大小.另外,有一定拓扑荷的涡旋光束可以在一定程度上降低大气湍流对传输光束焦面光强分布的影响.

Propagation Properties of Focused Partially Coherent Vortex Beams in Turbulent Atmosphere

The propagation properties of focused partially coherent Gauss-Schell model vortex beams in the turbulent atmosphere were investigated based on the extended Huygens-Fresnel principle and the quadratic approximation of phase structure function. Optical intensity expression on the focal plane was obtained. By use of the expression, the intensity distribution of such kind of beam on the focal plane in the turbulent atmosphere was studied. The results show that in the turbulent atmosphere, the singularity of the vortex beam lows down with the propagation distance increasing. The maintenance of singularity is better for the vortex beams with larger topological charge and longer spatially coherent length. When the focal length and turbulent strength are fixed, the topological charge and coherent length of the source can be adjusted to control the behavior of intensity distribution on the focal plane and size of the focal spot. Vortex beams with larger topological charge can be resistant to the turbulent effects on the intensity distribution on the focal plane to some extent.