STABILITY OF STATIONARY DARK WAVES GUIDED BY NONLINEAR SURFACES AND WAVE-GUIDES

The stability properties of stationary waves supported by a linear self-defocusing surface and a linear thin film sandwiched between two identical self-defocusing bounding media are investigated analytically with exact solutions. It is found that dark surface and gray guided modes are stable, whereas higher-order dark guided modes are unstable. A finite-difference beam propagation method is used to confirm these analytical results, to study the propagation of some nonstationary solutions, and to show that end-firing excitation of stable modes should be possible.