湍流大气中J_0相关部分相干平顶光束的传输特性

Propagation properties of J_0-correlated partially coherent flat-topped beams in a turbulent atmosphere

为了研究相干度为零阶贝塞耳函数的部分相干平顶光束的传输特性,采用广义惠更斯-菲涅耳公式得到了J_0相关部分相干平顶光束通过湍流大气的平均光强分布,并利用空间2阶矩法得到了均方根束宽的解析表达式;分析了传输距离、相干长度、大气折射率结构常数、阶数对光强分布特性和光束扩展的影响。结果表明,J_0部分相干平顶光束的阶数越高,相干长度越小,光束受湍流的影响就越小;改变光源的相干度可以使光束在湍流大气中的中心光强达到最大。

In order to study propagation properties of J0-correlated partially coherent flat-topped beams in atmospheric turbulence,the average intensity distribution were derived based on extended Huygens-Fresnel principle, and the analytical expression of beams waist width was obtained with the second-order moment method. Then, the effects of propagation distance , correlation lengths of source, structure constant and orders of flat-topped beams on average intensity distribution and beam width were analyzed. It was show that higher order flat-topped beam was less affected by atmospheric turbulence and it was less broadened. Results also show that maximum central intensity value can be obtained by adjusting the correlation lengths of source.