Improved coupled-mode analysis of nonlinear distributed feedback structures

Coupled-mode theory is employed to describe the nonlinear behaviour of a distributed feedback grating, including intensity-dependent terms resulting from the periodic variations in the nonlinearity. The improved coupled-mode analysis leads to modified values for the on and off-switching intensities, as demonstrated numerically.On leave from Dpto. Tecnologia Fotónica, Universidad Politécnica de Madrid, Ciudad Universitaria, 28040 Madrid, Spain.