Leon Poladian School of Mathematics and Statistics and Optical Fibre Technology Centre, University of Sydney Methods for modelling imperfections in optical fibres: design and manufacturing implications Wednesday 12th, May 14:05-15:55pm, Carslaw Building Room 359. Highly multimode graded-index fibres with an approximately parabolic profile and large core area dominate many short-haul applications due to low cost, ease of splicing and high bandwidths. The large bandwidth is dependent on irreversible mode mixing due to imperfections that arise from the way the fibre is manufactured. The introduction of microstructured fibres, which achieve an effective graded index by an arrangement of small holes of various sizes and spacings introduce new degrees of freedom and flexibility into the design and manufacture of these fibres. Unfortunately, conventional results about mode mixing do not apply directly to this new class of fibres. I will look at how equilibrium lengths, power distributions, pulse spreading and loss are derived for mode mixing due to surface imperfections on the holes.