The optimal IDT aperture and the aperture ratio are determined by calculating diffraction response.
最佳的IDT孔径和孔径比值由计算滤波器衍射频响确定。
2
For the diffraction of a small aperture, the scalar diffraction has been modified by the vector diffraction theory.
在微小孔衍射的情况下，还讨论了矢量衍射理论对标量衍射理论相关处理的修正。
3
By this way we can design high diffraction efficiency, as well as lager numerical aperture diffractive lens under current machine fabrication condition.