8.1 Introduction

Computer-aided design (CAD) has been a vital initial ingredient in the realisation of very large-scale integrated (VLSI) electronic circuits. Now in optoelectronics projects, mathematical modelling, although at present lacking the sophistication of CAD in VLSI, is being recognised as a key component in the design of devices and systems [1]. One thrust of the book has been to lay out the physical- and mathematical-modelling techniques for the electromagnetic and electronic interactions within distributed feedback lasers to give better explanations and to facilitate new designs. This chapter outlines further areas in optoelectronics where such modelling will be at the forefront in the design of more effective prototypes. Optical systems where arrays of devices may be interconnected are one such important area and are discussed in Section 8.2. Novel concepts such as that of the push-pull laser (Section 8.3), tunable lasers with Bragg gratings (Section 8.4), and surface-emitting lasers (Section 8.5) are all candidate areas for applications of the modelling principles given in this text. The future for mathematical modelling, coupled with a sound physical understanding, is bright, extensive and assured.