准相位型光子筛设计

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。

Design of Quasi-Phase Photon Sieve

A design of quasi-phase photon sieve is proposed. The pinholes of the quasi-phase photon sieve distributed in black and white plate zones have different ratios of diameter to zone width to obtain π phase shift, so that all of them have positive contribution to the field value at the desired focal point. The quasi-phase photon sieve does not need to process the rest and reduce the technology difficult of traditional phase photon sieve. Compared with the traditional photon sieve, the quasi-phase one with the same specific minimum feature size has bigger numerical aperture and smaller focal spot size. Furthermore, compared with the multi-region photon sieve, with the same specific minimum feature size and numerical aperture, the quasi-phase photon sieve has smaller focal spot size and better focus characteristics. The quasi-phase photon sieve provids a new way for the design of photon seieve with high humerical aperture.