Nonstationary nonlinear phenomena in optical slab-waveguides. I. General theory

Generalizing the stationary coupled-mode concept, nonstationary field equations for slowly varying field envelopes are derived. These field equations are combined with the equations of motion for the non-linear polarization and the inversion as well yielding a set of coupled differential equations applicable to a variety of nonstationary phenomena in waveguides. Pulse shaping and SIT of pulses interacting with a thin layer of two-level system are considered in detail.