利用杨氏双缝干涉讨论Talbot效应

利用杨氏双缝干涉原理讨论了平行光垂直照射下光栅的Tablot及分数Tablot现象.在成像平面上所观察到的光栅衍射条纹实质上是光栅中一定缝距的许多双缝对的杨氏干涉条纹的可除相干叠加条纹，其条纹间距和明暗中心位置都未变化;但是像相对于光栅即条纹分布相对于光栅刻线可能有半个周期的偏移，这可由双缝对参数α的奇偶决定，如果α为偶数则没有偏移，如果α为奇数则有偏移.

Discuss of Talbot Effect Basing on Young's Double-slit Interference

Basing on Young′s double-slit interference, the grating′s Talbot and fractional Talbot phenomena under illumination of parallel homochromatic wave were discussed. The grating diffraction fringes on the imaging plane results virtually from the so-called erasable coherent superposition of many Young′s interference fringes of double-slit with certain distance within the grating. Although the distance between fringes and the places of bright and dark fringe were not unvaried, there would be a shift of half period of the image versus the grating viz. fringe distribution versus scratches of grating. This shift would be determined by parity of parameter α of double-slit, namely that when α is even, the shift don′t appear, while α is odd, it appear.