TABLE OF CONTENTS The invention of semiconductor diode lasers [1 4] along with their ability to be directly modulated with information [5,6] and the invention of optical-fibre communication [7 9] in the 1960s 1970s have together had far-reaching effects on telecommunications leading to extensive optical-fibre communication networks and systems [10 12]. This book explores one aspect of this success story. High-performance optical-fibre systems need sources with a number of features:
stable single-frequency output;
modulation capability of gigabit/s;
stable operating lifetimes measured in 10 6 ?10 8 hours at room temperature; and
manufacturability.
The distributed-feedback (DFB) laser has these qualities and is now a standard device. The design and development of these lasers has proved to be fascinating work for those involved, and the physical and numerical modelling which has gone into developing these lasers is the topic of this book. Although the text concentrates on lasers with distributed feedback, the modelling work presented is more widely applicable and it is hoped that the reader will be as excited as the authors by the unfolding story.
The earliest semiconductor diode lasers [1 4] were straightforward p-n homojunctions formed in crystalline blocks of gallium arsenide (GaAs), or GaP xAs 1 -x [4], with typical dimensions of the order of a few hundred microns. In such lasers, two opposing parallel facets provide reflective optical feedback, hence forming a Fabry-Perot resonator (see, e.g. [13]) but of sufficiently small cross-section that the radial fringes, typically associated with this...
