Cover story: Zhou Y, Liang G F, Wen Z Q, et al. Recent research progress in optical super-resolution planar meta-lenses[J]. Opto-Electron Eng, 2021, 48(12): 210399

Breaking through the theoretical resolution limit in the optical mechanism and realizing super-resolution optical point-spread-function is important in achieving super-resolution focusing and imaging, which have great potential applications in laser processing, super-resolution microscopy and telescope systems. In recent years, with the development of optical metasurfaces, provides a more flexible means for the development of a new type of super-resolution planar super-lens. 

This article reviews the recent research progress of super-resolution planar metalenses based on optical metasurfaces and related testing techniques. We introduce different methods to produce multiple-wavelength achromatic super-resolution metalenses and corresponding focusing results, as well as the continuous broadband achromatic super-resolution metalenses. Meanwhile, we explain the ways to design vectorial super-resolution meta-lenses, such as by phase and polarization manipulations and show the corresponding results. A new idea using an optical microscope to directly image the focused optical field is elaborated and compared with other existing methods. Finally, we present the typical applications of super-resolution metalenses in some areas such as confocal microscopy, micro/nano fabrication and nanometic displacement detection. The problems faced in this field and future research priorities and directions are also discussed in this review paper.