Eur. Phys. J. B 32, 291-296 (2003)
https://doi.org/10.1140/epjb/e2003-00100-1

Extended nature of coupled optical interface modes in Thue-Morse dielectric superlattices

National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing 210093, PR China

Corresponding author: ^a gjin@nju.edu.cn

Received: 24 September 2002
Revised: 11 January 2003
Published online: 11 April 2003

Abstract

We investigate coupled optical interface modes in Thue-Morse (TM) dielectric superlattices composed of two kinds of materials with frequency-dependent dielectric functions. Four basic transfer matrices are derived in the dielectric continuum approximation. By a standard matrix operation method, the trace map of the global transfer matrix in this configuration is obtained. Under Born-von Kármán boundary conditions, the frequency spectra are calculated and their branching rules together with the quartet property are elucidated. It is further proved rigorously that nearly all eigenmodes in this framework have extended nature. The quartet of the eigenmodes is illuminated analytically. The common features and pronounced differences compared with coupled optical interface modes in periodic and Fibonacci dielectric superlattices as well as with other collective elementary excitations in TM structures are also revealed. 61.44.Br Quasicrystals