多高斯-谢尔模型光束在海洋湍流中的传输特性研究

Propagation Properties of Multi-Gaussian Schell-Model Beams through Oceanic Turbulence

基于最近发展的描述海洋湍流的空间功率谱函数和线性介质中广义惠更斯-菲涅耳积分公式，推导了多高斯-谢尔模型光束的光强、相干度及光束质量分子肝的解析表达式，研究了海洋湍流对多高斯谢尔模型光束传输特性的影响。数值计算结果表明，海洋湍流对多高斯-谢尔模型光束传输特性有着重要影响。适当地选择光束参数，在远场光强不仅可以形成平顶分布，而且这种平顶分布在湍流中能够保持相当长的距离，并且多高斯-谢尔模型光束的级次N越大，湍流诱导的光束扩展越小。

Based on the model developed recently for describing a spatial power spectrum function of clear oceanic water and the extended Huygens-Fresnel integral in linear media, the effects of oceanic turbulence on propagation properties of a multi-Gaussian Schell-model （MGSM） beam is studied. The analytic expressions such as the spectral density, the degree of coherence and the propagation factor M^2 of the beam are derived. Numerical results show that, the oceanic turbulence has a significant influence on propagation properties of a MGSM beam. With the suitable choice of beam parameters, the center of the intensity profile not only forms a plateau in the far-field but also the formed plateau can keep a long distance in oceanic turbulence. Furthermore, a MGSM beam with a large source parameter N could further reduce turbulence-induced spreading effect.