小尺度遮光物“黑滴”现象的研究及数值模拟

Analysis of the Black Drop Effect Caused by Small Size Shade and Its Numerical Simulation

透过手指间的狭缝,逆光可以观察到"黑滴"现象,利用简单的光学仪器可以清晰再现这种小尺度遮光物产生的"黑滴"现象。遮光物形状和空间位置的不同会导致其产生的影子间发生不同的相互作用,产生的"黑滴"现象也不尽相同。使用Matlab软件,以惠更斯-菲涅尔原理为基础,模拟呈现了多种条件下小尺度遮光物影子的变化情况,同样也能产生出"黑滴"现象。数值模拟结果与实物模拟结果基本吻合,且数值模拟过程中排除了其他因素的干扰,从而证明了光线的衍射是小尺度遮光物能产生黑滴现象的主要原因。这与天文观测中的"黑滴"现象成因有所不同。

The black drop effect could be observed through two adjacent fingertips.Such kinds of black drop effect,caused by small size shade,were presented with just several optical apparatus.The shade in varying sizes and positions could cause different black drop effects.Taking advantage of the Matlab,the black drop effect from different objects was successfully simulated based on the Huygens-Fresnel principle.The simulation process removed noises,and therefore,diffraction proves to be a primary cause of such black drop effect,which is quite different from the black drop effect acquired in astro-observation.