Spectral patterns underlying polarization-enhanced diffractive interference are distinguishable by complex trigonometry

Abstract

Superpositioned modes from scatterers in periodic arrays that prescribe spectral interference patterns are distinguishable using an analytic description. Interference arising from irradiation of ordered lattices with polarizable components yields far-field spectral patterns in which extraordinary features appear at resonant frequencies associated with lattice geometry. Organization of nanostructures utilizing these features has been limited by complexity of electrodynamic descriptions for coupling between these plasmon resonance energies and diffracted spectral modes. The trigonometric description shows how changing lattice constant and incident wavelength to adjust coupling between phase-dependent constructive interference and isometric values of plasmonic gold nanostructure polarizability results in extraordinary spectral features.

Coupled dipole plasmonics of nanoantennas in discontinuous, complex dielectric environments

“…Square lattices of spheres comprising a metasurface support Fano-type coupling between far-field diffraction and near-field LSPR, resulting in a CLR when the lattice constant exceeds the plasmon wavelength [7,12,57]. Diffracted phase interference [38] patterns that coincide with CLRs at 650 nm and 646 nm were also observed. Completely destructive interferences at 446 nm and 631 nm accrue from diffractive scattering in a 630 nm square grating.…”

“…Relative to AuNS lattices in homogeneous environments, complex-valued dielectric substrates introduce spectral aberrations due to decoupling of the Fano resonance [22], phase [38] and waveguide [58] effects, new plasmon decay paths [56], and out-of-plane dipole interactions [59]. Non-vacuum environments red-shift the LSPR and lattice constant at unequal rates due to molecular polarization and wavelength contraction, respectively.…”

“…The rsa-CDA [20,38,40] reduced computational time by taking advantage of π/2 rotational symmetry in square lattices [40]. Dielectric data for Au reported by Johnson and Christy was used in all simulations [51].…”

“…The CDA describes electrodynamics of a nanoantenna lattice comprising a metasurface by treating each constituent antenna as a point dipole with scalar polarizability [20,38,39]. Charge density polarization of each antenna, P, is calculated according to antenna polarizability (α) and cumulative contributions from the incident field, E o , and adjacent dipoles comprising the lattice, E lat , viz.,…”

Role of coupling of localized surface plasmon modes in transmission properties of compound structure metamaterials

“…Metamaterials have attracted considerable attention in recent years due to their unique optical properties [1][2][3][4][5][6][7][8][9][10], especially the noble metallic holes structure and particles structure. With respect to the particles metallic structure, it could be possible to excite the resonance of localized surface plasmon modes (LSP) on the surface of the particles metallic structure [11].…”