Novel slow light waveguide with controllable delay-bandwidth product and utra-low dispersion

We demonstrate a novel type of slow light photonic crystal waveguide which can produce unusual "U" type group index - frequency curves with constant group index g n(g) over large bandwidth. By shifting the boundaries of this waveguide, flexible control of g n(g) (10 < n(g) < 210) with large bandwidth (1nm<Delta lambda<43nm centered at 1550nm) and normalized Delay-Bandwidth Product (0.1363<DBP<0.3143) are achieved. Additionally, depending on the chosen waveguide geometry, extremely low group velocity dispersion (GVD<0.5 ps.nm(-1).mm(-1)), with controllable group velocity dispersion of both signs is obtained. (C) 2010 Optical Society of America