Geometrically tunable slow light based on a modified photonic crystal waveguide

In this paper, we have proposed a design for slow light in a modified photonic crystal waveguide by inserting reduced air holes along the middle of the waveguide with a half period of the lattice and by shifting the second rows of holes toward the center of the modified waveguide. A wideband slow light with a high group index and low group velocity dispersion has been achieved. A nearly constant group index of 21, 20, 35.5 and 65 over 20.3 nm, 15.6 nm, 9.5 nm, 5.3 nm bandwidth in the environment of 1550 nm, respectively, are also obtained.