Continuously Tunable Slow and Fast Light by Using an Optically Pumped Tilted Fiber Bragg Grating Written in an Erbium/Ytterbium Co-Doped Fiber

Continuously tunable slow and fast light is achieved by using a tilted fiber Bragg grating (TFBG) written in an erbium/ytterbium co-doped fiber. By pumping the TFBG, the magnitude and group delay responses of the cladding mode resonances are changed, which can be used to achieve a tunable time delay or time advance. The proposed method is demonstrated by an experiment in which a tunable time delay from to 18 ps corresponding to a fast to a slow light is achieved for a 13.5-GHz Gaussian pulse.