Nonlinear Optics in Guided Geometries - Abstract

Kinsler, Paul

Towards the far end of that fibre: Pulse propagation models with minimal assumptions

Simple pulse propagation models don't need numerous approximations. We just use one of the most obvious features of optical pulses in waveguides -- the direction they're heading. This directional nature allows us to rewrite our initial model -- either Maxwell's equations or a second order wave equation -- in terms of its oppositely propagating components. Then, for weak coupling, we can reduce the model to a first order one describing only the forward field. Co-moving frames, smooth envelopes, and negligible second order derivatives are not needed. I discuss both factorization and directional field approaches, and compare their advantages and disadvantages. E.g., directional fields allow easy description of guides with both electric and magnetic responses.