超构透镜的色差调控应用

Application of chromatic aberration control of metalens

超构表面是由精心设计和排布的亚波长纳米单元组成的平面元件,其可以在微观尺度下调制电磁场,从而实现波前的任意调控。目前,它已被用来灵活地操纵相位、偏振、振幅等各种光学参数。超构透镜是超构表面中相当重要且非常活跃的一个研究方向,由于其厚度在波长量级,与传统光学透镜相比,能够显著增加光学器件的集成度并且降低结构复杂度。但是,单元结构材料的固有色散以及结构几何形状衍射效应导致的色差会严重影响超构透镜的成像质量,从而限制了其在光电子器件中的潜在应用。本文首先讨论超构透镜控制色差的原理。随后回顾了几种重要的成像应用,包括分立波长消色差,宽带聚焦成像,光场成像等重要的成像系统。最后,本文对超构透镜未来的发展方向和应用前景做出展望。

Metasurface consists of the arrangement of the specially designed subwavelength nano units,which is the two-dimensional counterpart of metamaterial.Metasurface can modulate the electromagnetic field on a microscopic scale to allow the arbitrary wavefront manipulation.At present,it has been used to flexibly control various optical parameters such as phase,polarization,and amplitude.Among all of the applications based on metasurfaces,metalens is no doubt one of the most important and basic research interset.Because its thickness is on the order of wavelength,compared with traditional optical lenses,it can significantly increase the integration of optical devices and reduce the systematic complexity.However,the chromatic aberration caused by the inherent dispersion of the material of the unit structure and the diffraction effect of the structural geometry will severely influence the imaging quality of the metalens,and hence isolating us from a rich variety of advanced applications.Herein,we firstly discuss the principle of controlling chromatic aberration with metalens.Then we review several important imaging applications,including discrete wavelength achromatic,broadband focus imaging,light field imaging and other important imaging systems.Finally,this article makes some prospects for the incoming development direction and potential applications of metalens.