提出一种大口径光子筛的优化设计方案,将同一菲涅耳环带上的所有小孔看作一个整体,在非近轴小孔远场衍射模型的基础上通过近似和变换推导出单一小孔环带的光场公式。重点讨论小孔环带衍射模型所需要满足的内部结构条件。数据计算表明,小孔环带衍射模型计算所得的光子筛焦平面光场分布与传统的远场小孔衍射模型计算所得结果基本一致,并且使用小孔环带衍射模型所设计的大口径光子筛在焦平面上的聚焦特性较好,计算效率得到极大的提高。这种新的设计方法将有助于完善光子筛衍射理论,为大口径光子筛的优化设计提供了一种全新的形式。

We propose an improved design solution of large-aperture photon sieve. All the pinholes in one Fresnel ring are regarded as a whole, and the diffraction field formula is deduced after approximation and transformation based on the nonparaxial far-field pinhole diffraction model. The main work of this paper focuses on the internal condition of pinhole ring diffraction model. According to calculation, the diffraction field calculated by the pinhole ring model is basically consistent with that calculated by the traditional far-field pinhole model, the large photon sieve designed by the new method focuses well on the focal plane, and the computational efficiency is greatly improved. This method could benefit the flexibility of design and fabricating the larger aperture photon sieve.