Improved line-defect structures for photonic-crystal waveguides with high group velocity

Through the analysis of the guided modes in simple photonic-crystal (PC) sl ab waveguides, we have established a simple and essential interpretation fo r the dispersion structure of the guided modes: the structure of the disper sion curves is the result of interactions between the index-confined mode a nd the gap-confined mode. This interpretation gave us guidelines for increa sing group velocities near the zone boundary, or for solving the severe lig ht-line problem in PC slab waveguides with dielectric claddings. Applying t hese guidelines, we proposed novel waveguide structures that promise fine t ransmission characteristics, (C) 2001 Elsevier Science B.V. All rights rese rved.