Radial shear interference metasurface

The radial shearing interferometer has increasingly attracted interests in various areas, such as adaptive optics systems, laser systems, optical inspection, and topographic surveys. However, traditional RSIs suffer from the enormous volume, irregular interferogram, and non-adjustable shear rate, which severely limits their application. Metasurfaces, as a latest breakthrough, can provide perfect building blocks for the optical wavefront operation of artificial materials at sub-wavelength scales. In this work, we have proposed a radial shearing interference plate with subwavelength spatial resolution based on all-dielectric compound metalenses. The incident beam to the compound metalenses is divided evenly and uniformly into a convergent and a divergent wavefront beam with no high-order diffraction, enabling the radial shearing interference plate high contrast interference in the overlapping region. There are at least 320 steply changed phases per 2π period within total 24π phase range, demonstrating high-precision phase modulation ability. The experimental results show that the average contrast is 0.958. The MRSIP have the advantages of ultra-compact structure, outstanding phase modulation ability, polarization insensitive, subwavelength spatial resolution, regular interferogram, high contrast, high energy utilization, and adjustable SR, implying its potential to transient wavefront detection, aero-optical, topographic surveys, particularly in the realm of outdoor applications and so on.