Lorentzian model for nonlinear switching in a microresonator structure

We show that the optical response of two channel waveguides coupled by a microresonator is well described by a Lorentzian model. Using this model we derive a set of coupled differential equations that describe Kerr nonlinear optical pulse propagation and optical switching in systems coupled by a few microresonators. The equations are valid even when the pulse is within the gap of the structure