浅析两类光源下的菲涅耳圆孔衍射

Concise Remark on Fresnel's Circular Aperture Diffraction Under two Types of Light Sources

为了探明高斯光束和平面光波的菲涅耳圆孔衍射特性,利用菲涅耳-基尔霍夫积分公式,研究了这两类光波在轴线上的相对光强分布随传输距离和圆孔半径的变化规律,以及束腰半径对高斯光束菲涅耳衍射光强演变的影响。结果表明:实验课中以高斯光束作为入射光源,而在理论课中以普通平面光波作为入射光源,进行圆孔衍射教学是完全可行的。指出该研究方法数学积分简单、物理图像清晰,适宜作为普通高中物理教师的教学参考。

In order to investigate the Fresnel diffraction characteristics of Gaussian beam and plane light wave passing through the circular apertures,the variation rule of the relative light intensity distribution of these two types of beams on the axes with the transmission distances and the radius of the circular aperture sizes is studied by using the Fresnel-Kirchhoff integral formula,the influence of the beam waist radius on the evolution of the Fresnel diffraction intensity of Gaussian beam is analyzed as well.It is proved that using the Gaussian beam as the incident light source in the experimental curriculum,but the ordinary plane light wave as the incident light source in theoretical course is entirely feasible.It is pointed out that the research method is suitable for teaching reference of physics teachers in senior high schools because of its simple mathematical integration and clear physical image.