Designer Metasurfaces for Antireflective Applications Enabled by Advanced Nanoparticle Technology (Advanced Optical Materials 10/2022)

In article number 2200151, Nathan J. Ray, Jae-Hyuck Yoo, Hoang T. Nguyen, and Eyal Feigenbaum demonstrate the ability to generate substrate-engraved metasurfaces that can be tailored within a broad design space to satisfy large-area antireflective (AR) applications for bandpass or broadband needs. This is done by dry etching through an advanced nanoparticle etching mask, permitting control over the area coverage of the sub-wavelength metasurface features, as well as the resultant feature lateral spacing, height, and shape. Using this approach, two metasurfaces were fabricated: 1) vertical sidewall nanofeature metasurface for AR applications at 351 nm, and 2) sloped sidewall metasurface designed for broadband ultra-low reflectance applications. To the best of the authors' knowledge, this is the first demonstration of a broadband AR capable of this performance.