Printable all-dielectric water-based absorber

Abstract The phase interplay between overlapping electric and magnetic dipoles of equal amplitude generated by exclusively alldielectric structures presents an intriguing paradigm in the manipulation of electromagnetic energy. Here, we offer a holistic implementation by proposing an additive manufacturing route and associated design principles that enable the programming and fabrication of synthetic multi-material microstructures. In turn, we compose, manufacture and experimentally validate the first demonstrable 3d printed all-dielectric electromagnetic broadband absorbers that point the way to circumventing the technical limitations of conventional metal-dielectric absorber configurations. One of the key innovations is to judicially distribute a dispersive soft matter with a high-dielectric constant, such as water, in a low-dielectric matrix to enhance wave absorption at a reduced length scale. In part, these results extend the promise of additive manufacturing and illustrate the power of topology optimisation to create carefully crafted magnetic and electric responses that are sure to find new applications across the electromagnetic spectrum

Facile metagrating holograms with broadband and extreme angle tolerance

Metasurfaces: Wide-Angle Holograms The use of plasmonic metasurfaces has enabled the realization of broadband holograms that can operate at extreme angles approaching grazing incidence. Zi-Lan Deng and coworkers from Jinan University, Southern University of Science and Technology, Shenzhen University and Nankai University fabricated the holograms from an array of closely spaced, identical silver nanorods (90nm wide, 200nm long) on top of a silicon substrate coated with a thin layer of silver and then a layer of SiO2. The phenomenon of extraordinary optical diffraction allows highly efficient diffraction at very large angles and customizing the spacing of the nanorods allows the desired phase profile to be programmed, into the surface. The design, which operates in the visible and near-infrared range, may prove useful for various holographic applications including data encryption, anti-counterfeiting and 3D displays