Andrew Docherty School of Mathematics and Statistics, University of Sydney Asymptotic modelling of timing shifts in modern optical communications systems Wednesday 6th September 14:05-14:55pm, Carslaw Building Room 373. Current long-distance optical communications systems span the world and allow transmission of data at high-speeds between continents. Since the first submarine commercial optical cable was opened in 1988, optical fiber technology has improved hugely and with it the transmission capacities for long distance cables. A short history of optical communications and summary of current optical communications technologies will be given. This will lead to a mathematical model of the propagation of a pulse in a typical modern communications line. Focusing on one major limiting factor, cross-talk between channels, an asymptotic method is developed for calculating its impact in modern high-capacity optical communications. Predictions of the asymptotic theory agree well with direct numerical simulations of the underlying equations and provide much understanding of the underlying phenomena itself.