Visible light waveband Dammann grating based on all-dielectric metasurface.

Dammann gratings (DGs) can generate a spot array in a particular arrangement. In recent years, DGs have been used in many fields such as laser beam splitting and optical coupling. Nanograting encoding technology can achieve a high signal-to-noise ratio and high-efficiency diffraction distribution; it also provides new design ideas for realizing the miniaturization and deviceization of DGs. In this work, we have comprehensively studied the DG based on an all-dielectric metasurface, which can produce a 5×5 diffraction spot array with a diffraction angle of 20∘×20∘. In an operation waveband from 650 to 690 nm, the DG has superior performance with high efficiency ≥60%; meanwhile, it achieves a relative low contrast ratio ≤0.33. Owing to high efficiency, wide waveband performance, and polarization insensitive property, the all-dielectric metasurface DG can provide possibilities for various application, including laser technology and optical information processing.