提出了一种准相位型光子筛。该准相位型光子筛通过改变暗环上小孔直径与带宽的比值,对焦点处的相位分布进行调制,使通过亮环和暗环上小孔的光波在焦点处发生相长干涉,生成聚焦光斑。该准相位型光子筛无需对基底进行特殊处理,即可完成相位型光子筛的制作,降低了加工难度。和普通振幅型光子筛相比,在相同最小加工尺寸的条件下,准相位型光子筛具有较大的数值孔径,可降低聚焦光斑尺寸。并且,和多区光子筛相比,在同样的最小加工尺寸及数值孔径的条件下,准相位型光子筛光斑尺寸及质量均优于对方。为大数值孔径光子筛设计提供了一种新的设计方法。 A quasi-phase photonic sieve is proposed. The quasi-phase photonic sieve modulates the phase distribution at the focal point by changing the ratio of the diameter of the small hole on the dark ring to the bandwidth so that the light waves passing through the bright ring and the small hole on the dark ring constructively interfere at the focal point to generate the focus Spot. The quasi-phase photonic sieve does not require special treatment of the substrate to complete the production of the phase type photonic sieve, thus reducing the processing difficulty. Compared with the ordinary amplitude type photonic sieve, the quasi-phase type photonic sieve has larger numerical aperture under the same minimum working size, which can reduce the focal spot size. And, compared with the multi-zone photon sieve, with the same minimum working size and numerical aperture, the spot size and quality of the quasi-phase photonic sieve are superior to each other. It provides a new design method for large numerical aperture photonic sieve design.