Surface plasmon generation and light transmission by isolated nanoholes and arrays of nanoholes in thin metal films

Abstract

Extensive 3-D finite-difference time-domain simulations are carried out to elucidate the nature of surface plasmon polaritons (SPPs) and localized surface plasmon polaritons (LSPs) generated by nanoscale holes in thin metallic films interacting with light. Both isolated nanoholes and square arrays of nanoholes in gold films are considered. For isolated nanoholes, we expand on an earlier discussion of Yin et al. [Appl. Phys. Lett. 85, 467-469 (2004)] on the origins of fringe patterns in the film and the role of nearfield scanning optical microscope probe interactions. The associated light transmission of a single nanohole is enhanced when a LSP excitation of the nanohole itself is excited. Periodic arrays of nanoholes exhibit more complex behavior, with light transmission peaks exhibiting distinct minima and maxima that can be very well described with Fano lineshape models. This behavior is correlated with the coupling of SPP Bloch waves and more directly transmitted waves through the holes.

Enhanced Förster Resonance Energy Transfer on Single Metal Particle. 2. Dependence on Donor−Acceptor Separation Distance, Particle Size, and Distance from Metal Surface

“…FDTD is now the start-of-the-art method for solving Maxwell's equations for complex geometries. [24][25][26][27][28][29][30][31][32][33][34][35][36][37] Being a direct time and space solution, FDTD offers the user a unique insight into all types of problems in photonics. Furthermore, FDTD can also be used to obtain the frequency solution by exploiting Fourier transforms, thus enabling a full range of useful quantities such as the complex Poynting vector and the transmission/reflection of light, in addition to fields around particles to be calculated.…”

Single-Molecule Studies on Fluorescently Labeled Silver Particles: Effects of Particle Size

“…[22][23][24][25][26][27][28][29][30][31][32][33][34] Since FDTD is a direct time and space solution, it offers the user a unique insight into all types of problems in electromagnetics and photonics. Furthermore, FDTD can also be used to obtain the frequency solution by exploiting Fourier transforms; thus, a full range of useful quantities in addition to fields around particles can be calculated, such as the complex Poynting vector and the transmission/reflection of light.…”

“…In the FDTD technique, Maxwell's curl equations are discretized by using finite-difference approximations in both time and space that are easy to program and are accurate. [22][23][24][25][26][27][28][29][30][31][32][33][34] To achieve high accuracy for realizing the spatial derivatives involved, the algorithm positions the components of the electric and magnetic field about a unit cell of the lattice that constitutes the FDTD computational domain. Each individual cube in the grid is called the Yee cell as it was first designed elegantly by Yee.…”

The optical response of nanostructured surfaces and the composite diffracted evanescent wave model

“…Other interpretations based on "dynamical diffraction" in periodic slit and hole arrays [6,7] or various kinds of resonant cavity modes in 1-D slits and slit arrays [8,9] have also been proposed. Reassessment of the earlier data by new numerical studies [10] and new measurements [11] have prompted a sharp downward revision of the enhanced transmission factor from ≃ 1000 to ≃ 10 and have motivated the development of a new model of surface wave excitation termed the composite diffracted evanescent wave (CDEW) model [11]. This model builds a composite surface wave from the large distribution of diffracted evanescent modes (the inhomogeneous modes of the "angular spectrum representation" of wave fields [12]) generated by a subwavelength feature such as a hole, slit, or groove when subjected to an external source of propagating wave excitation.…”