Three‐Dimensional Microscopic Topography Measurement Based on Liquid Crystal Spatial Differentiator

Abstract Microscopic topography measurement is a fundamental tool for materials characterization, biological imaging, and quality inspection. Conventional measurement methods face significant challenges in balancing cost and efficiency, particularly when characterizing unlabeled transparent specimens. To address these limitations, a three‐dimensional microscopic topography measurement technique is proposed and experimentally demonstrated utilizing liquid crystal‐based spatial differentiation. Through experimental validation, dimensional parameters of transparent structures are successfully quantified with 99% lateral agreement and 10 nm axial uncertainty. The resolution can be further improved by utilizing imaging system with higher magnification and LC with a larger spatial period. Compared with conventional methods, our approach offers real‐time performance, operation simplicity, high accuracy, and low cost. These advantages endow the technique with significant potential for applications spanning industrial quality monitoring, advanced materials characterization, and high‐contrast biological imaging, thereby opening up new possibilities in these fields.