TABLE OF CONTENTS The time-domain techniques (Chapter 7) for solving the electromagnetic interactions in lasers have led to powerful and efficient routines which are capable of solving a wide range of (single-and) multimodal problems covering Fabry-Perot lasers, uniform and phase-shifted DFB lasers, all of which may be driven with digital or analogue modulation. Similar routines have also been built using transmission-line laser modelling [2 4], an alternative time-domain technique with many of the virtues of the techniques discussed in Chapter 7. Considerable effort has been put into developing a general optical-system simulator based on embedded-device models that are interconnected with passive components so as to mimic system performance [5]. The laser simulator can, for example, model highspeed digital-modulation performance, fast pulse generation, passive mode locking, and dynamic instabilities. Extending such time-domain analyses to optical subsystems and systems containing many components will provide excellent insights into the interactions between these components over a wide range of frequencies. This section gives examples of some initial applications of such an optical-systems simulator.
The first ingredient for a'systems simulator' is to have numerical models for all the components within the system. The basic numerical techniques described in Chapter 7 can be applied to Fabry-Perot and DFB lasers, and also to semiconductor optical amplifiers (SOA) which are essentially Fabry-Perot lasers with weak (or zero) reflection at their facets. Some geometrically complicated components may require techniques such as beam-propagation [6] or 'finite elements' [7] to solve the electromagnetic fields but these lie...
