部分相干双涡旋光束在海洋湍流中的传输

基于广义惠更斯―菲涅耳原理,推导了部分相 干双涡旋光束在海洋湍流中传输时光强分布的理论表 达式,详细研究了部分相干双涡旋光束在海洋湍流中的传输特性。研究结果表明,在传输距 离较小的情况 下,双环结构扩展随着外环拓扑荷数的增加而增大,传输一定距离以后光束转化为空心分布 ,当传输距离 足够长后,光强分布转化为类高斯分布。研究还发现,双涡旋光束在海洋湍流中的强度分布 也受到海洋湍 流相关参数的影响,并且随着海洋湍流的相关参数的改变,光束转化为类高斯分布所需要的 传输距离也随 着改变。另外,在传输距离较短的情况下,光源的相干性越好,光束的双环结构越明显,并 且中间的“暗核” 越明显。所得结果对于部分相干双涡旋光束应用于水下湍流环境有着重要的意义。

Propagation of partially coherent double-vortex beam in the oceanic turbulence

On the basis of the extended Huygens-Fresnel principle,the formula f or the partially coherent double- vortex beam in the oceanic turbulence has been derived.Then the intensity of bea m propagation in the oceanic turbulence has been investigated in detail.It is shown that the spreading of the beam increases with increasing the charges of the outer ring,and the intensity distributions are double-rin g structure near the source plane.As the propagation distance increases,the intensity distribution will spread and c hange into the single ring.Then,the single ring gradually transforms into a Gaussian-like distribution when the propagation distance is long enough.It is also found that the intensity distributions of the double-vortex beams in the o cean turbulence are influenced by the oceanic turbulence correlation parameters.As the oceanic turbulence correlation parameters change,the propagation distance required to transform beam into a Gaussian-like distributi on also changes.In addition,in the case of short propagation distance,the better the coherence of the light source is,the more obvious the double-ring structure of the beam is.The obtained results are of great significance for the application of partially coherent double-vortex beams in the optical communication and underwater exploration in the ocean.