Description of dispersion properties of metals by means of the critical points model and application to the study of resonant structures using the FDTD method

Abstract

Using a combination of Drude and critical points models, we show that the permittivity of several metals can be more efficiently described than using the well-known Drude–Lorentz model. The numerical implementation in a finite-difference time-domain code together with a non-uniform grid enables the study of thin metallic intermediate layers often neglected in simulations but found in realistic resonant structures.

Nanostructured Biosensors: Influence of Adhesion Layer, Roughness and Size on the LSPR: A Parametric Study

“…is used to stick gold on substrate. This adhesion layer is usually neglected in simulations, excepted in a few studies for Surface Plasmon Resonance based biosensor [3,6,7], and in the case of cylinder-based transducer [42]. Nevertheless in the theoretical and numerical studies, the roughness of the gold nanostructures are neglected and the nanometric adhesion layer of gold on substrate is rarely included.…”

“…This chapter is dedicated to the parametric study of a specific nanobiosensor, made of a grating of gold nanocylinders deposited on a dielectric substrate and the goal is to investigate the influence of adhesion layer and roughness on the position of the LSPR as a function of the geometrical parameters of cylinders: their diameter D and height h. The first section is devoted to the validation of the model by comparison to previous simulations with Finite Difference Time Domain [42], and to experimental results [20,21,23]. The analysis of the parametric study is given in section 3 and a method to deduce heuristic laws for the LSPR is also proposed, before concluding.…”

Probing and Controlling Photothermal Heat Generation in Plasmonic Nanostructures

“…Probes aligned to the central, vertical axis of each antenna were place at 5 nm above and 6 nm inside each structure to capture and respectively. Each simulation was performed with a FDTD solver, and the optical properties of the metal were fit to the Drude model 31 . The heat source density was found by inputting the calculated electric field at the specified probe location into the following equation,…”

Dual capacitive-inductive nature of periodic graphene patches: Transmission characteristics at low-terahertz frequencies

“…The Drude model is a poor approximation for metals in this frequency range, and here we use a fit based on measured data 48 for the permittivity, utilizing an augmented Drude model. 49 Figure 9(a) shows the surface impedance for three different thickness values (t) of the metal (here t = d is fixed and is not the skin depth as used for the THz calculations), with the corresponding transmissivity shown in Fig. 9(b) for a five-layer structure, where D = 100 nm, g = 10 nm, h = 166 nm, and r = 1 (results were computed using the transfer-matrix approach).…”