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。

Based on the direct modulation of diffraction channels by localized surface plasmon resonances from metallic nano-structure or Mie scattering from all-dielectric micro/nano-structures, a metagrating emerges as an ideal platform for high-efficiency manipulation of wide-angle diffractive optical fields. In this paper, the physics and applications behind metagrating-based manipulation of diffractive optical fields are reviewed. First, metagratings with desirable high diffraction efficiency are introduced, including different working schemes of reflection and transmission modes as well as symmetric, asymmetric, and reconfigurable configurations. Second, by incorporating the high diffraction metagrating with displacement-coded phase modulation mechanism, arbitrary wavefront shaping with a wide-angle range can be realized, leading to their special applications in high numerical aperture metalens, angle-tunable multi-functional devices, and wide-angle hologram metagratings. Third, considering the metagrating as a bridge to connect the surface wave and free-space wave, the mutual conversion between a free-space wavefront and a surface wavefront is analyzed. Finally, we give a brief summary and the development trend and the potential applications of metagratings are prospected.