Inverse-designed Jones matrix metasurfaces for high-performance meta-polarizers

Polarizers have always been an important optical component for optical engineering and have played an indispensable part of polarization imaging systems.Metasurface polarizers provide an excellent platform to achieve miniaturization,high resolution,and low cost of polarization imaging systems.Here,we proposed freeform metasurface polarizers derived by adjoint-based inverse design of a full-Jones matrix with gradient-descent optimization.We designed multiple freeform polarizers with different filtered states of polarization(SOPs),including circular polarizers,elliptical polarizers,and linear polarizers that could cover the full Poincarésphere.Note that near-unitary polarization dichroism and the ultrahigh polarization extinction ratio(ER)reaching 50 d B were achieved for optimized circular polarizers.The multiple freeform polarizers with filtered polarization state locating at four vertices of an inscribed regular tetrahedron of the Poincarésphere are designed to form a full-Stokes parameters micropolarizer array.Our work provides a novel approach,we believe,for the design of meta-polarizers that may have potential applications in polarization imaging,polarization detection,and communication.

超构光栅调控衍射光场的物理及应用

基于局域表面等离激元或电介质微纳结构米氏散射的超构光栅对衍射通道的直接调制为高效率、大角度光场调控提供了优良平台。对超构光栅调控衍射光场的物理机理及应用开发进行了概述。首先,从高衍射效率超构光栅的构建机理出发,分别介绍了反射式、透射式、对称型、非对称型及可重构超构光栅的典型实现方式;其次,介绍了通过结合高衍射效率超构光栅与位移编码型相位调制机制,实现任意大角度光波前高效调控的典型方法,概述了高数值孔径透镜、角度可调型多功能光器件、大角度全息超构光栅等方面的研究进展;然后,介绍了以超构光栅作为连接自由空间光与表面波的桥梁,自由空间光波前与表面光波前相互转化方面的集成光调控平台;最后给出了简要小结,并对超构光栅未来的发展趋势与应用前景进行了展望。