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The far‐field resolution of traditional optical imaging systems is restricted by the Abbe diffraction limit, a direct result of the wave nature of light. To break this limit, one applicable approach is to reduce the effective size of the point‐spread‐function (PSF). In the past decades, great endeavors have been made to produce an effective super‐resolution PSF by exploiting different mechanisms, including optical nonlinearities and structured light illumination. However, it is difficult to apply these methods to objects at far distance miles away. Here, the study proposes a new approach to achieving super‐resolution imaging for far‐distance objects by utilizing angular magnification. To this end, a new class of metalenses with angular magnification is first theoretically and experimentally validated and demonstrated. Both theoretical and experimental results have demonstrated a more than twofold enhancement beyond the traditional angular‐resolution limit. The proposed approach is of promising potential in the applications of super‐resolution telescopes and remote sensing. [ABSTRACT FROM AUTHOR]

Recently, developments in superoscillatory optical devices have allowed for label‐free far‐field optical super‐resolution technology by allowing engineering of optical point‐spread functions beyond the traditional Abbe diffraction limit. However, such superoscillatory optical devices are optimized for the normal‐incident operation, which inevitably leads to a comparatively slow imaging acquisition rate in the application of super‐resolution microscopy. Here, a super‐resolution metalens is demonstrated with a high numerical aperture that can focus oblique incident light into a hot spot with a size smaller than the diffraction limit at the visible wavelength. This super‐resolution metalens has a numerical aperture of as large as 0.97, a focal length of 38.0 µm, a radius of 151.9 µm, and a field of view of 4° that enables super‐resolution focusing on the focal plane at a wavelength of λ = 632.8 nm. In a 5.6λ × 5.6λ field of view on the focal plane, the size of the focal spot is smaller than 0.45λ, which is only 0.874 times the corresponding Abbe diffraction limit. The super‐resolution metalens offers a promising way toward fast‐scanning label‐free far‐field super‐resolution microscopy. [ABSTRACT FROM AUTHOR]