菲涅耳区板分区规则

Zoning rule of Fresnel zone plate

根据Huygens-Fresnel的波束管理论,充分利用第1区的有效能量,并利用各个区所贡献的合成场强在焦点处同相的奇数分区,摒弃各合成场强在焦点处反相的偶数分区,导出了平面菲涅耳区板的一维条带的最优分区新规则.从基尔霍夫绕射公式出发进一步研究菲涅耳区板的二维圆环的分区规则.分为标量场(非极化波)绕射和矢量场(极化波)绕射2种情况,得出最优分区与传统分区在短焦距情况下存在差异、而随着焦距的增长渐趋一致的结论.

An new optimal rule for one dimensional Frensel zone plate with parallel strips was proposed. The zoning rules for two dimensional ring of Frensel zone plate is studied by means of Kirchhoff diffraction formula. Both the scalar-field （ i. e. non-polarized wave） diffraction and vector-field （ i. e. polarized plane wave） diffraction are calculated and analyzed. It is concluded that the optimal and traditional zoning rules are different in the case of shorter focal length; but approach to the same one when the focal length is increasing.