Computer modelling of photonic devices for optical measurements

The emergence and progress of optical technologies have enabled them to have a profound effect in telecommunications and consumer electronics and also for optical sensing and measurements. To exploit fully the potential of the available faster transmission rates, higher bandwidths, and low transmission losses available with optics, the aim is to increase the capability of optical systems by introducing approaches based on new physical principles and on the optimization of such devices. Analytic modelling techniques are available, but however, lightwave systems do not lend themselves well to such models, due to the frequent use of unrealistic assumptions and design restrictions in some cases. A better approach is computer aided modelling which can be flexible and has been developed for the range of lightwave systems, with the potential to take into account important systems features. A wide range of computer-aided design and simulation packages have been developed for a considerable number of photonic devices. Modelling work carried out on MMI (multimode interference) devices is presented, as representative of this.