用非相干叠加法研究部分相干光在湍流大气中的光束扩展

Study on the Spreading of Partially Coherent Beams in Turbulent Atmosphere by Using Incoherent Superposition Method

以高斯谢尔模型(GSM)光束作为部分相干光的典型例子,研究了部分相干光在湍流大气中的光束扩展.基于广义的惠更斯-菲涅耳原理,采用将GSM光束用高阶厄米-高斯光束的非相干叠加的方法得到了GSM光束在湍流大气中的均方根束宽表达式.研究表明,光束的扩展随着湍流大气的折射率结构常数C2n的增大而加剧,并且有较小相干长度σμ的GSM光束受湍流大气的影响比有较大σμ的GSM光束小.

The Gaussian Schell-medel（GSM） beam is taken as a typical example of partially coherent beam, the spreading of partially coherent beam in turbulent atmosphere is studied. Based on the generalized Huygens-Fresnel principle, the mean square root width of GSM beam in turbulent atmosphere is derived by using the incoherent superposition of higher-order Hermite-Gaussian beams. It is shown that the spreading of beams increases with the increase of refraction index structure constant C^2n , and GSM beams with smaller coherent length are less sensitive to the effects of turbulence than those with larger coherent length.