Abstract

Modulational instability in periodic media with a Kerr nonlinearity is investigated using coupled mode theory. In the presence of anomalous dispersion, the standard nonlinear Schroedinger results are obtained at low powers, though at higher powers deviations from this well-known behavior occur. For normal dispersion an instability with a finite threshold is found. This instability has no equivalent in the nonlinear Schroedinger equation.

© 1998 Optical Society of America