关键词: 傅里叶光学∣光强分布∣矩孔菲涅尔衍射∣数值积分

Abstract:

According to Fresnel-Kirchhoff diffraction formula, got the light intensity expression about diffraction at rectangular apertures and made numerical calculation, analyzed the influence of the size of aperture on light intensity of rectangular diffraction. The light intensity distribution was characterized by Fraunhofer diffraction when the projection of light source located in the symmetry center of rectangular aperture and the size of aperture is small enough .With the increasing of the size of aperture, the ratio of adjacent peak and valley value of light intensity is decreasing in the same region of geometric shadow, and more light intensity peak value appearing in the geometric illuminated district. The symmetry no longer existed when the projection of light source is not located in the symmetry center of rectangular aperture. At last the light intensity distribution of Fresnel diffraction at several rectangular apertures is calculated and analyzed.

Key words: Fourier optics∣light intensity distribution∣Fresnel diffraction at rectangular aperture∣numerical integration