Xie Ningzhi, Zhou Zhihao, Fröch Johannes E, Carson Matthew D, Majumdar Arka, Seibel Eric J, Böhringer Karl F
Department of Electrical and Computer Engineering, University of Washington, Seattle, WA, USA.
Department of Physics, Seattle, Washington, USA.
Commun Eng. 2025 Mar 19;4(1):53. doi: 10.1038/s44172-025-00377-7.
Metalenses, with their ultrathin thicknesses and their ease for achieving ultra small diameters, offer a promising alternative to refractive lenses in miniaturized imaging systems, such as endoscopes, potentially enabling applications in tightly confined spaces. However, traditional metalenses suffer from strong chromatic aberrations, limiting their utility in multi-color imaging. To address this limitation, here we present an inverse-designed polychromatic metalens with a diameter of 680 μm, focal length of 400 μm, and low dispersion across 3 distinct wavelengths at 643 nm, 532 nm, and 444 nm. The metalens collimates and steers light emitted from a scanning fiber tip, generating scanning beams across a 70° field-of-view to provide illumination for a scan-based imaging. The metalens provides a close-to-diffraction-limited 0.5° angular resolution, only restricted by the effective aperture of the system. The average relative efficiency among three design wavelengths is around 32% for on-axis angle and 13% averaged across the entire field-of-view. This work holds promise for the application of metalenses in endoscopes and other miniaturized imaging systems.
超颖透镜厚度超薄，易于实现超小直径，为内窥镜等小型成像系统中的折射透镜提供了一种很有前景的替代方案，有可能在狭窄空间中实现应用。然而，传统超颖透镜存在严重的色差，限制了它们在多色成像中的应用。为了解决这一限制，我们在此展示了一种通过逆向设计的多色超颖透镜，其直径为680μm，焦距为400μm，在643nm、532nm和444nm这3个不同波长下具有低色散。该超颖透镜准直并引导从扫描光纤尖端发射的光，在70°视场内产生扫描光束，为基于扫描的成像提供照明。该超颖透镜提供接近衍射极限的0.5°角分辨率，仅受系统有效孔径的限制。在三个设计波长下，轴上角度的平均相对效率约为32%，在整个视场内平均为13%。这项工作为超颖透镜在内窥镜和其他小型成像系统中的应用带来了希望。
