Ultra-thin sub-diffraction metalens with a wide field-of-view for UV focusing

In recent years, wide field -of -view imaging technology based on a metasurface has been widely applied. However, works on the reported sub -diffraction metalens with a wide fieldof -view indicate that multiple structures are essential to effectively eliminate aberrations, which results in a heavy device thickness and weakens the advantage of an ultrathin metasurface. To solve this problem, according to the super -oscillation theory and the translational symmetry of quadratic phase, as well as the principle of virtual aperture diaphragm based on wave vector filter, this Letter demonstrates a sub -diffraction metalens combined with a single quadratic metalens and a wave vector filter. Our design not only realizes the super -resolution effects of 0.74 to 0.75 times the diffraction limit in the wide field -of -view of nearly 180 degrees for the first time to our knowledge but also compresses the device thickness to the subwavelength order in principle. The proposed ultra -thin sub -diffraction metalens with a wide field -of -view is expected to be applied in the fields of super -resolution fast scanning imaging, information detection, small target recognition, and so on. (c) 2024 Optica Publishing Group