Chromatic dispersion compensators via highly dispersive photonic crystals

We calculated the phase index np, group index ng, and chromatic dispersion D from photonic band structures in two-dimensional (2D) photonic crystals consisting of triangular-arrayed cylindrical rods. We found that both the np and ng increase rapidly as the frequency of a propagating electromagnetic wave approaches the gap-band edges due to Bragg reflection, thus causing D to be large. The chromatic dispersion D is evaluated to be four to five orders of magnitude greater than the conventional single-mode fiber dispersion and should be useful as dispersion compensation for fiber-optic communications. In addition, the np, ng, and D of the 2D photonic crystals for E - and H -polarized waves are also examined.