Abstract

Solitary waves and solitons represent an important stable state of nonlinear systems in many fields of applied mathematics and physics such as fluid dynamics, elementary particle physics and laser science. In laser physics solitons are studied and applied mainly in optical fibres and waveguides. The soliton regime of pulse transmission in single-mode optical fibres permits drastic improvement of data transmission over large distances. Research on solitons is concentrated on solitons and solitary waves in homogeneous media whilst the study of solitons in periodic or otherwise inhomogeneous media started only recently. This already resulted in remarkable results, e.g. in the phenomenon of in-gap solitons.^[1] Our interest in solitons in periodic or otherwise inhomogenous media is related to applications in fibre optics as well as to the theory of pulsed distributed-feedback (DFB) and distributed-Bragg-reflector (DBR) lasers.

© 1992 IQEC