Dispersion characteristics of nonuniform Bragg gratings: Implications for WDM communication systems

The dispersive nature of Bragg gratings in transmission can result in pulse degradation which limits transmission rates and/or distances in WDM communication systems. Using an effective medium treatment we study theoretically and experimentally the dispersion characteristics of nonuniform Bragg gratings. We show that in the "wings" of a nonuniform Bragg grating the dispersion depends on only a few integrated properties of the grating. The results indicate that there are severe limitations to the engineering that can be done to minimize the dispersion in the wings of a grating by the design of its detailed structure. (C) 1998 Published by Elsevier Science B.V. All rights reserved.