Chirp-induced penalty on communication bit-rate of fiber Bragg grating based filter in dense wavelength-division multiplexed system

We have analyzed the transmission dispersion effect of a fiber Bragg grating when it is used as a filter in dense wavelength-division multiplexed system, and it is pointed out that only the dispersion effect of an upper-adjacent channel in the lower frequency side of the grating stopband, which will influence the transmission of the lower adjacent-channel, needs to be taken into account in an optical fiber-grating based filter. We have calculated the chirp-induced penalty on the dispersion-induced broadening of optical pulses in super-Gaussian style, which is almost a realistic pulse profile in a nonreturn-to-zero optical communication system, as well as the corresponding bit-rate limitation on the filter. A chirp-induced penalty coefficient is defined and the coefficient under different parameters of fiber Bragg grating and pulse chirp coefficient is calculated.