一种新型微分滤波器

用二元光学的方法将具有滤波功能的交叉光栅和具有聚焦功能的菲涅波带片组成一个复位相型元件，用它对光学图像微分，具有光路简单、调节方便、衍射效率高、效果良好等优点。

A New Filter of Difference

The phase type element is combined crossed grating,having filter ability,with Fresnel-zone plate having self-focusing,by binary optical methods. It is used as difference of optical pattern which has advantage of simple optical setup, convenience of adjustry, high diffraction efficiency and good result. The principle of pattern difference of this new type differential filter is discussed by Fresnel diffraction theory, the manufacture of this element is also introduced,and the experimental results are giren.