We demonstrate an all-optical tunable delay in fiber based on wavelength conversion, group-velocity dispersion, and wavelength reconversion. The device operates near 1550 nm and generates delays greater than 800 ps. Our delay technique has the combined advantages of continuous control of a wide range of delays from picoseconds to nanoseconds, for a wide range of signal pulse durations (ps to 10 ns), and an output signal wavelength and bandwidth that are the same as that of the input. The scheme can potentially produce fractional delays of 1000 and is applicable to both amplitude- and phase-shift keyed data.
