Metamaterial‐Assisted Illumination Nanoscopy with Exceptional Axial Resolution

Abstract Recent advancements in optical metamaterials have opened new possibilities in the exciting field of super‐resolution microscopies. The far‐field metamaterial‐assisted illumination nanoscopies (MAINs) have, very recently, enhanced the lateral resolution to one‐fifteenth of the optical wavelength. However, the axial localization accuracy of fluorophores in the MAINs remains rarely explored. Here, a MAIN with a nanometer‐scale axial localization accuracy is demonstrated by monitoring the distance‐dependent photobleaching dynamics of the fluorophores on top of an organic hyperbolic metamaterial (OHM) substrate under a wide‐field single‐objective microscope. With such a regular experimental configuration, 3D imaging of various biological samples with the resolution of ≈40 nm in the lateral dimensions and ≈5 nm in the axial dimension is realized. The demonstrated imaging modality enables the resolution of the 3D morphology of nanoscopic cellular structures with a significantly simplified experimental setup.