Tunability of the FBG group delay through acousto-optic modulation

► A fine control of the group delay of a fiber Bragg grating (FBG) is presented. ► It is based on an acoustic optic effect applied to the fiber. ► Tunability is obtained through adjustment of the acoustic wave parameters. ► A fast switching time of ∼17 μs is achieved. ► It can be used for different photonics applications such as optical delay lines.