Rigorous broadband investigation of liquid-crystal plasmonic structures using finite-difference time-domain dispersive-anisotropic models

Abstract

A finite-difference time-domain scheme is proposed for the rigorous study of liquid-crystal photonic and plasmonic structures. The model takes into account the full-tensor liquid-crystal anisotropy as well as the permittivity dispersion of all materials involved. Isotropic materials are modeled via a generalized critical points model, while the dispersion of the liquid-crystal indices is described by Lorentzian terms. The validity of the proposed scheme is verified via a series of examples, ranging from transmission through liquid-crystal waveplates and cholesteric slabs to the plasmonic response of arrays of gold nanostripes with a liquid-crystal overlayer and the dispersive properties of metal-liquid-crystal-metal plasmonic waveguides. Results are directly compared with reference analytical or frequency-domain numerical solutions.

An ADI-FDTD Formulation With Modified Lorentz Dispersion for the Study of Plasmonic Structures

“…The proposed model incorporates all widely used dispersive models, i.e., Debye, Drude and Lorentz [9], [10].…”

“…2) E n+1/2 z is updated explicitly by using (12b) with (10 are updated explicitly by using (7a) and (7b), by setting n ← n + 1/2. In [13] the CPML formulation is combined with the ADI-FDTD method for non-dispersive dielectrics.…”

“…The Drude-critical points (DCP) [5], the complex-conjugate pole-residue pairs (CCPR) [6] and the modified Lorentz (mLor) [7] model can more accurately describe the dielectric dispersion of metals in infrared and optical frequencies than the widely used Drude-Lorentz medium. The above dispersion models have been exploited in the study of plasmonic applications using explicit FDTD schemes [5], [8]- [10]. Recently, an implicit scheme was proposed, in which the trapezoidal recursive convolution (TRC) technique is combined with the DCP model and the LOD formulation [11].…”

“…A major advantage of the ADE approach is that it can be coupled with differential equations describing complex physics, such as anisotropic media [10], rate equations in laser simulations or nonliner dispersive effects. The proposed technique uses an order reduction for the mLor dispersive model and it is shown to be stable for arbitrarily large time steps.…”

Nonlinear Optical Phenomena in Smectic A Liquid Crystals

“…Substituting expressions (27)- (30) Eqs. (31) and (32) describe the parametric energy exchange between the fundamental waves, Eqs. (33) and (34) describe the cross-phase modulation (XPM) of these waves [6].…”