Plasmon polaritons in photonic superlattices containing a left-handed material

TL;DR

This paper investigates plasmon polaritons in one-dimensional photonic superlattices with left-handed materials, revealing how specific bandgap conditions suppress light-plasmon coupling and alter mode characteristics.

Contribution

It introduces a detailed analysis of plasmon polaritons in superlattices with dispersive left-handed materials, highlighting the impact of bandgap tuning on mode behavior.

Findings

Propagation of electric and magnetic plasmon polaritons in the superlattice.

Weakening of light-plasmon coupling within the photonic zero-order bandgap.

Transition from plasmon polariton to pure plasmon mode when plasma frequency is within the bandgap.

Abstract

We analyze one-dimensional photonic superlattices which alternate layers of air and a left-handed material. We assume Drude-type dispersive responses for the dielectric permittivity and magnetic permeability of the left-handed material. Maxwell's equations and the transfer-matrix technique are used to derive the dispersion relation for the propagation of obliquely incident optical fields. The photonic dispersion indicates that the growth-direction component of the electric (or magnetic) field leads to the propagation of electric (or magnetic) plasmon polaritons, for either TE or TM configurations. Furthermore, we show that if the plasma frequency is chosen within the photonic $<n(\omega)>=0$ zeroth-order bandgap, the coupling of light with plasmons weakens considerably. As light propagation is forbidden in that particular frequency region, the plasmon-polariton mode reduces to a pure plasmon mode.