Effects of dispersion in transmission of FBG in DWDM system on adjacent channel pulse shape

In future high bit-rate DWDM systems, the channel separations will be narrower and the bit-rate of single channel will be higher. The dispersion in transmission of fiber Bragg grating is a factor that cannot be neglected. We emphasize the effects of the 3(rd) order dispersion because the 3(rd) order dispersion is more detrimental for short pulses than the 2(nd) order dispersion. Furthermore, the 3(rd) order dispersion is always positive whether the wavelength of the adjacent channel is longer than Bragg wavelength or not. So the accumulated effects are more notable than the 2(nd) order dispersion, which can be positive or negative. We calculated the effects of the dispersion of FBG on pulses with 1ps, 2ps and 5ps pulse widths under channel separations of 50 GHz and 100 GHz. It is shown the 3(rd) order dispersion will be more detrimental in high bit-rate DWDM systems. This paper will give some guide to FBG design for ADM application. The method we use is split-step Fourier method.