We present and validate a new method for designing transmission gratings with high efficiency for the 1st diffraction order across the visible spectrum. The high efficiency is achieved by redirecting light to the 1st order via asymmetric composite elements, which scatter light in the same direction as the 1st diffraction order. By focusing on increasing the directional scattering of the grating elements, the design remains simple yet effective. As a result, the gratings are relatively easy to fabricate. Measurements of fabricated gratings show a relative increase of over 40% for a large part of the visible spectrum.@en

We show that composite nanoparticles can be designed to scatter light into a desired direction. By choosing the materials of the nanoparticle carefully, the phase of the scattered light by the different components can be controlled. This leads to constructive interference is certain directions and destructive interference in others, resulting in directional scattering obtainable for a large bandwidth. FEM simulations were used to validate the theory. Furthermore, SiO2/Au nanoparticles were fabricated and measured confirming the directional scattering.

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We show that the scattering of light by a composite nanoparticle leads to directional scattering through the phase difference between the light scattered by each of the materials. The resulting scatter pattern is experimentally verified.

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