Fig. 4: Optical characterization and applications.
From: Controlled filamentation instability as a scalable fabrication approach to flexible metamaterials
a Experimental measurements of R01 against incident beam wavelength for two fibers of similar NW array period p ≈ 1.4 μm, with different NW diameters. b From RCWA, R01 spectra for various NW diameters d (p = 1.4 μm). The two fibers assessed experimentally are represented with dotted lines. c For given values of incident beam wavelength λi and a given ratio period/diameter p/d, we vary p and d (respectively in [50 nm, 400 nm] and [2d, 6d]) to find maximal R01. A heatmap of R01 is plotted showing high diffraction for λi > 650 nm and high grating fill factors (filaments closer to each other). d Simulated scattering cross-section spectra of a single ChG NW of varying diameter under a normally incident plane wave in air. Three Mie resonant modes are identified with dashed lines and maps of their normalized field intensity around the wire are plotted as inserts, for a wire diameter of 240 nm. e Simulated phase shift spectra in transmission for a 300 nm-period NW array and varying diameters. f Normalized transmission amplitude and full phase shift coverage (dashed line in (e)) through As2Se3 NW arrays of varying diameter, with period p = 300 nm, under normally-incident illumination at 800 nm. In figures (a–f), for clarity, only results for an incident beam polarized parallel to the NWs are shown. g Long-range metaperiodicity following the template. The distance between filaments can be tailored individually, paving the way towards one-dimensional metasurfaces.
