Evanescent waves and complex rays for modal propagation in curved open waveguides

摘要: Evanescent wave tracking (EWT) has provided a new and effective method for analyzing high-frequency trapped mode propagation in longitudinally homogeneous open dielectric waveguides. It therefore been suggestive to extend EWT so as account field leakage when the waveguide is curved. A circularly bent two-dimensional guiding structure served prototype present study. Even this canonical configuration, direct generalization of procedure, attempted first, not achieved bridge transition from predominantly evanescent radiating regime observer moves away guide axis on convex side. Therefore, problem analyzed alternatively by complex ray tracing (CRT) that involves continuation initial conditions, boundaries, etc., into coordinate space. This approach, structured around congruences generated caustic, successful. By self-consistent closure ...