部分相干厄米-高斯光束杨氏实验中的光强分布

Intensity distribution in Young's experiment with partially coherent Hermite-Gaussian beams

将杨氏干涉实验作为双缝衍射现象处理,以部分相干厄米-高斯(H-G)光束为例,研究分析了多模部分相干光的杨氏双缝干涉光强和干涉条纹可见度的空间分布。数值计算说明,多模部分相干光束的空间相干参数、模阶数和缝遮拦比对衍射场中光强的空间分布(干涉花样)都有影响。当多模部分相干光的阶数为奇数时,轴上光强与光束的相干性会出现相消干涉;当多模部分相干光的阶数为偶数时,轴上光强与光束的相干性会出现相长干涉等。

Taking the partially coherent Hermite-Gaussian（H-G） beam as a typical example,this paper studies the distribution of diffraction intensity and the visibility of interference fringes in Young＇s two-slit set-up illuminated by the multi-mode partially coherent beam,where the Young＇s interference experiment is regarded as a two-slit diffraction phenomenon.Numerical calculations show that,the spatial coherence parameter and mode orders of partially coherent beams,and the obstruction ratio of the two-slit set-up all have some effect on the distribution of the diffraction intensity（i.e.interference pattern） and the visibility of the interference fringes.With the coherence of the partially coherent beams increasing,destructive interference may appear on the axis when the mode orders of the incident beams are odd,while constructive interference may appear on the axis when the mode orders are even.