Design and fabrication of a tunable dispersion-slope compensating module based on strain-chirped fiber Bragg gratings

We report the design and fabrication of a tunable dispersion-slope compensating module based on a concatenation of a linearly strain-chirped fiber Bragg grating (FBG) and a nonlinearly strain-chirped FBG. By bending a substrate in an S shape, on which each FBG is mounted, we can adjust only the dispersion slope while maintaining the group-velocity dispersion as well as the center wavelength. The dispersion slope can be tuned up to -58.4 ps/nm/sup 2/ in this module for a bandwidth larger than 1.65 nm.