Slow light transmission in two-dimension square photonic crystal waveguide

The slow light propagation in a waveguide formed by line defect in two-dimensional square photonic crystal is analyzed by use of the plane wave expansion method. The numerically simulation results show that the group velocity in the photonic crystal waveguide can be decreased by increasing the filling factor and the radius of defect rods, and decreasing the radius of the rods adjacent to the waveguide, of which the main factor of the influence on the group velocity is the defect rod size. By tuning the three factors above, the value of the group velocity can be as smaller as 0.015c. Furthermore, for air rod square photonic crystal waveguide, the group velocity in the photonic crystal waveguide can be decreased by decreasing the radius of the air rods, and the value of the group velocity is only 0.008c.