Tunable WDM dispersion compensation with fixed bandwidth and fixed passband center wavelength using a uniform FBG

We report an fiber Bragg grating-based tunable dispersion compensator with fixed bandwidth and fixed passband center wavelength for wavelength-division-multiplexing (WDM) channels. Chirping of the grating is achieved by bending a cantilever, and the tunability is realized by controlling the length of the induced chirping within a longer uniform grating. Due to the fixed center wavelength and bandwidth, crosstalk from adjacent wavelength bands is minimized and a single passband can potentially accommodate several WDM channels. We demonstrate tunable dispersion compensation up to 1500 ps/nm with a 10-cm uniform grating. Moreover, both negative and positive 400-ps/nm values are achieved in a single device with 2-nm bandwidth.