title: Plasmon-enhanced structural coloration of metal films with isotropic Pinwheel nanoparticle arrays.
abstract: We experimentally demonstrate angle-insensitive (i.e., isotropic) coloration of nanostructured metal surfaces by engineered light scattering from homogenized Pinwheel aperiodic arrays of gold nanoparticles deposited on gold substrates. In sharp contrast to the colorimetric responses of periodically nanopatterned surfaces, which strongly depend on the observation angle, Pinwheel nanoparticle arrays give rise to intense and isotropic structural coloration enhanced by plasmonic resonance. Pinwheel nanoparticle arrays with isotropic Fourier space were fabricated on a gold thin film and investigated using dark-field scattering and angle-resolved reflectivity measurements. Isotropic green coloration of metal films was demonstrated on Pinwheel patterns, with greatly reduced angular sensitivity and enhanced spatial uniformity of coloration compared to both periodic and random arrays. These findings, which are supported by coupled-dipole numerical simulations of differential scattering cross sections and radiation diagrams, could advance plasmonic applications to display, optical tagging and colorimetric sensing technologies.
authors: Department of Electrical and Computer Engineering & Photonics Center, Boston University, 8 St. Mary’s St., Boston, Massachusetts 02215, USA.
authors: Sylvanus Y
authors: SY
authors: Lee
authors: Carlo
authors: C
authors: Forestiere
authors: Alyssa J
authors: AJ
authors: Pasquale
authors: Jacob
authors: J
authors: Trevino
authors: Gary
authors: G
authors: Walsh
authors: Paola
authors: P
authors: Galli
authors: Marco
authors: M
authors: Romagnoli
authors: Luca
authors: L
authors: Dal Negro
mesh_terms: D003116:Color; D006046:Gold / Q000737:chemistry*; D008422:Materials Testing; D008567:Membranes, Artificial; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D036103:Nanotechnology / Q000379:methods*; D020349:Surface Plasmon Resonance / Q000379:methods*; D013499:Surface Properties
chemical_list: D008567:Membranes, Artificial; D006046:Gold