Astigmatic Displacement Microscopy (ADM) with Subnanometer Axial Resolution for Three-Dimensional (3D) Morphological Characterization

In response to the growing demand for advanced micro/nano characterization in materials and surface-interface sciences, we report a highly sensitive astigmatism displacement microscopy (ADM) system with subnanometer axial resolution of 0.1 nm. This low-power, noncontact, nondestructive, and rapid optical 3D imaging technique enables large-area characterization with exceptional imaging quality. Using ADM, we achieved high-quality 3D morphology characterization of Au nanoplates, CD-ROMs, semiconductor Si wafers, and few-layer 2D materials (like MoS₂). For few-layer 2D materials, ADM demonstrates a linear capability to resolve atomic layer numbers. Additionally, ADM successfully characterized transparent and semitransparent single crystals, even in the presence of inclination-induced interference fringes. The development of ADM provides a powerful tool for micro/nanoscale characterization, with significant implications for materials and surface-interface research.