Dispersionless Slow Light in Fiber Bragg Gratings with Active Materials

In this paper, an atomic system is suggested to be embedded in the fiber Bragg gratings (FBG) to reduce the group velocity and to eliminate the dispersion of slow light. We demonstrate numerically that the pulse can be transmitted at the group velocity 0.147c dispersionlessly in the FBG, compared with 0.193c and 56% of FWHM broadening without the atomic system.