Physica 148A (1988) 343-355
North-Holland, Amsterdam
ELECTROMAGNETIC WAVE PROPAGATION IN
QUASIPERIODICALLY STRATIFIED MEDIA
D. WÜRTZ*, T. SCHNEIDER and M.P. SOERENSEN**
IBM Research Division, Zurich Research Laboratory, 8803 Rüschlikon, Switzerland
Received 19 June 1987
We explore the wave number dependence of the transmission of electromagnetic waves in
quasiperiodic dielectric multilayers. Using the transfer-matrix technique, we also establish the
connection to the tight-binding Schrödinger problem. As an example, we consider a multilayer
constructed according to the Fibonacci inflation rule. In contrast to the periodic case, we find a
highly fragmented distribution of stop bands and self-similar structure in the wave number
dependence of transmission.
1. Introduction
Recently, the one-dimensional Schrödinger equation with quasiperiodic
potential evoked considerable interest
1
-
6
). This equation displays fragmented
eigenvalue spectra because a quasiperiodic potential is intermediate between a
random one, yielding exponentially localized wave functions
7
), and the
periodic potentials, leading to energy bands and gaps. Moreover, the new
ability to produce semiconductor heterostructures with control of each layer
allows experimental realizations of these structures
8
). Here, the one-dimen-
sional Schrödinger equation models the properties of the heterostructure
perpendicular to the layers.
In this work, we explore a related problem, electromagnetic wave propaga-
tion in layered and quasiperiodic dielectric media. The regular counterpart,
periodically stratified media, has a long history9) and many important applica-
tions, ranging from optical filters to reftectors, solid-state lasers and optical
fibers
10
). In analogy to the Schrödinger problem, one expects quasiperiodic
stratified media to represent an intermediate case between the periodic and
*Permanent address: Institut für Theoretische Physik, Universität Heidelberg, Philosophenweg
19, D-6900 Heidelberg, Fed. Rep. Germany.
**Permanent address: Laboratory of Applied Mathematical Physics, Tcchnical University of
Denmark, Building 303, DK-2800 Lyngby, Denmark.
0378-4371 /88/$03.50 © Elsevier Science Publishers B.V.
(North-Holland Physics Publishing Division)