利用简单直观的非近似方法分析双光栅干涉仪,证明了该干涉仪的干涉条纹反差不受照明光源相干性限制时,光源的空间位置不影响条纹形状,仍是等间距直条纹.给出了消除光源相干性限制的一般条件,并讨论了条件失配对干涉仪的影响.

In this paper the two- grating interferometer is analysized by means of nonapproximation. It is shown that when the number and the contrast of fringes from the interferometer are not limited by the coherence of its illuminating light, it is also not influenced by the position in space of the light source and is still capable of yielding equal spacing straight fringe pattern. The general conditions are derived under which the temporal or/and spatial coherence of illumination has no influence on the fringe patterns. Further, the effect on the interferometer due to the mismatch of these conditions is discussed.