Improved line defect structures for slow light transmission in photonic crystal waveguide

The slow light propagation in a line waveguide in photonic crystal slab has been investigated. It is found that the filling factor of the photonic crystal and the radius of defect rods decide the propagation character of the guided mode in photonic crystal bandgap. As increasing the filling factor, the group velocity in the photonic crystal waveguide decreases rapidly. The effect on the group velocity of defect rods size is slighter than the former. It has been demonstrated that, by tuning the filling factor and size of defect rods, the group velocity will be smaller than 0.01c. Using a simpler PCW structure we have obtained smaller group velocity than most investigations.