Metalens-Based Dual Light-Sheet Fluorescence Microscopy

Light-sheet fluorescence microscopy (LSFM) provides optically sectioned fluorescence images with excellent background rejection for rapid and volumetric imaging. However, traditional LSFM typically relies on single-sided illumination and the stripe artifacts due to partial obstruction or scattering of the illumination beam, resulting in the formation of shadow artifacts. Uneven illumination, particularly in non-transparent samples, results in poor contrast in certain regions of the image and reduces image uniformity. To address this problem in compact fashion, a metalens-based dual-sided illumination LSFM (MDI-LSFM) is presented, which utilizes twin light-sheets for uniform sample illumination. This is achieved by the integration of a pair of cylindrical metalenses in LSFM, forming two identical light-sheets from opposite sides of the sample. Through a rigorous experimental setup, the system-level structure optimization of MDI-LSFM is successfully demonstrated to form an engineering extension by observing ex vivo images of mice lung tissues, achieving a lateral resolution of 1.7 µm with optical sectioning capability of 6.8 µm. The approach eliminates shadow artifacts and simplifies system configuration by replacing bulky optics with compact, efficient metalenses, while achieving a large field of view, high resolution, and fast imaging. These advantages enable wide-ranging biomedical applications for in situ tissue imaging and diagnostics. © 2025 The Author(s). Small Methods published by Wiley-VCH GmbH.