Compensation of slow light velocity dispersion in tapered period one-dimensional photonic crystal coupled cavities

Optical waveguides formed from coupled ultrahigh-Q cavities are investigated by finite-difference time-domain (FDTD) simulation. Ultra-high group velocity dispersion together with a group velocity as low as 3times10
^-5
c is predicted at the band edge. It is shown that full compensation of the group velocity dispersion for chip free slow light (~c/100) over a bandwidth of 230 GHz is possible using a coupled-cavity waveguide comprising cavities of Q ~ 10
⁶
.