关于超透镜斜入射时调制传递函数曲线的研究

Investigations of modulation transfer functions for oblique incidences on metalens

为了实现光学系统的集成和小型化,提高光学系统的成像质量,设计了一种基于广义斯涅尔定律和几何相位的平面超透镜。通过在超透镜界面处设计双曲面相位分布,将入射圆偏振平面波阵面转换为球形波阵面,将光聚焦在期望焦距处,并且在垂直入射时能够实现衍射极限聚焦。分析了入射光以不同角度入射时,光斑的调制传递函数(MTF)曲线,阐述了不同角度入射光入射时导致MTF曲线下降的原因。该分析对平面超透镜的进一步优化设计具有一定的指导意义,有助于实现小型化、集成化的光学系统。

In order to realize integrations and miniaturizations of optical systems and improve optical imaging qualities of the systems, a planar metalens that based on generalized Snell’s law and geometric phase. The metalens converts an incident circularly polarized plane wave into a spherical wave by designing a hyperbolic phase distribution at the interface to focus the light at a desired focal length, which can achieve diffraction limited focusing when the light is at the normal incidence. The modulation transfer function(MTF) curve of the spot is further analyzed when the incident light is at different angles. Finally, the reason why the MTF curve is decreased at different incident angles is explained. This investigation has certain guiding significance for the further optimization design of the planar metalens, which contributes to the realization of miniaturized and integrated optical systems.