Multiresonant Nonlocal Metasurfaces

Optical metasurfaces supporting localized resonanceshave becomea versatile platform for shaping the wavefront of light, but theirlow quality (Q-) factor modes inevitably modify thewavefront over extended momentum and frequency space, resulting inlimited spectral and angular control. In contrast, periodic nonlocalmetasurfaces have been providing great flexibility for both spectraland angular selectivity but with limited spatial control. Here, weintroduce multiresonant nonlocal metasurfaces capable of shaping thespatial properties of light using several resonances with widely disparate Q-factors. In contrast to previous designs, the narrowbandresonant transmission punctuates a broadband resonant reflection windowenabled by a highly symmetric array, achieving simultaneous spectralfiltering and wavefront shaping in the transmission mode. Throughrationally designed perturbations, we realize nonlocal flat lensessuitable as compact band-pass imaging devices, ideally suited formicroscopy. We further employ modified topology optimization to demonstratehigh-quality-factor metagratings for extreme wavefront transformationswith large efficiency.

Automated summary

Optical metasurfaces have been widely used in shaping the wavefront of light, but their low quality (Q-) factor modes have limited the spectral and angular control. In this study, we introduce multiresonant nonlocal metasurfaces that can shape the spatial properties of light using resonances with different Q-factors. Through rational design, we achieve nonlocal flat lenses suitable for compact band-pass imaging devices and demonstrate high-quality-factor metagratings for extreme wavefront transformations with large efficiency using modified topology optimization.