基于蒙特卡罗的光栅衍射条纹强度仿真预测

为更形象、直观地展现光栅衍射现象,了解光栅衍射条纹强度变化情况,研究了基于蒙特卡罗方法和MATLAB的光栅衍射条纹强度预测方法。依照惠更斯-菲涅耳原理获取光栅衍射强度分布,利用蒙特卡罗方法随机模拟。采用MATLAB软件仿真研究光栅衍射条纹强度变化情况,通过各参数值变化获得相应衍射光强分布情况。研究时改变光栅缝数分析光栅衍射条纹主极大强度变化情况,改变光栅常数、缝宽以及波长等参数,分析光栅衍射条纹次极大强度变化情况。研究得出：光栅缝数越多,主极大越大,光栅衍射条纹强度越强,光栅衍射主极大强度受多条单缝衍射强度调制;光栅常数越大次级大强度分布密度越大,缝宽增加衍射现象变弱;波长变大光栅衍射谱线渐宽,锐度降低。

Prediction of Grating Diffraction Fringe Intensity based on Monte Carlo Method and MATLAB

In order to display grating diffraction phenomenon more vividly and intuitively and understand the change of grating diffraction fringe intensity, the monte carlo method and MATLAB based grating diffraction fringe intensity prediction method were studied. According to huygens-fresnel principle, grating diffraction intensity distribution was obtained, and monte carlo method was used for random simulation. MATLAB software was used to simulate the change of grating diffraction intensity, and the corresponding diffraction intensity distribution was obtained through the change of each parameter value. During the study, the change of the main maximum strength of grating diffraction fringes was analyzed by changing the number of grating slit, and the parameters such as grating constant, slit width and wavelength were changed to analyze the change of the submaximum strength of grating diffraction fringes. The results show that the larger the number of grating slits, the larger the main maximum, and the stronger the intensity of grating diffraction fringes. The main maximum intensity of grating diffraction is modulated by multiple single-slit diffraction intensities. The larger the grating constant is, the higher the intensity distribution density is, the weaker the diffraction phenomenon is when the slit width increases. As the wavelength increases, the diffraction line of grating becomes wider and the sharpness decreases.