摘要
The chromatic aberration of metasurfaces limits their application. How to cancel or utilize the large chromatic dispersion of metasurfaces becomes an important issue. Here, we design Si-based metasurfaces to realize flexible chromatic dispersion manipulation in mid-infrared region. We demonstrate the broadband achromatic metalens and achromatic gradient metasurface to cancel the chromatic aberration over a continuous bandwidth(8–12 μm). In contrast, the metalens and gradient metasurface with enhanced chromatic dispersion have also been realized, where the focal length and deflection angle with different wavelengths vary more significantly than the conventional devices designed with geometric phase. These demonstrations indicate promising potential applications.
基金
supported by the National Key R&D Program of China (Nos. 2017YFA0303700,2017YFA0303702,and 2016YFA0202103)
the National Natural Science Foundation of China (Nos. 11822406,11834007,11774162,11674166,11674167,11674168,11621091,11774164,and 91850204)。
