Surface topography detection based on an optical differential metasurface

Surface topography detection can extract critical characteristics from objects, playing an important role in target identification and precision measurement. Here, an optical method with the advantages of low power consumption, high speed, and simple devices is proposed to realize the surface topography detection of low-contrast phase objects. By constructing reflected light paths, a metasurface can perform spatial differential operation via receiving the light directly reflected from a target. Therefore, our scheme is experimentally demonstrated as having remarkable universality, which can be used not only for opaque objects, but also for transparent pure phase objects. It provides a new, to the best of our knowledge, application for optical differential metasurfaces in precise detection of microscale surface topography. (c) 2023 Optica Publishing Group

Automated summary

This study proposes an optical method for surface topography detection of low-contrast phase objects, which achieves spatial differential operation by constructing reflected light paths. The method is demonstrated to be universal and accurate, and applicable to both opaque and transparent pure phase objects.