Blazed pillar metasurfaces for high-performance near-infrared optics

Metasurfaces are excellent platforms for implementing flat optical components, offering unmatched versatility and seamless integration potential. However, the simultaneous achievement of high efficiency and stability across the angular and spectral domains continues to pose a substantial challenge. In this work, we show that blazing the pillar facets of simple phase-gradient metasurfaces improves the diffraction efficiency at the -1st diffraction order by values up to 8%, as demonstrated for three different pillar materials on top of silica substrates. Furthermore, this design offers improved performance over an incidence angle range of 30°a nd a wavelength band of about 80 nm in the near-infrared region, enabling its deployment for applications such as Optical Wireless Communications leveraging Wavelength Division Multiplexing systems, as well as optical fiber links that aim to integrate passive devices. These findings underscore the effectiveness of blazed facet engineering in enhancing the efficiency of phase-gradient metasurfaces while preserving the original design. Moreover, the inherent angular and spectral stability of the proposed metasurfaces demonstrate strong potential for next-generation optical communication technologies.