Tunable optical delay line based on four-wave mixing wavelength conversion and dispersion in optical fibers

In recent years,tunable optical delay line has attracted much research interest for its applications in optical communications,optical signal processing and optical control of phased array antennas in microwave communications. Compared with optical delay line based on slow light techniques, all-optical wavelength conversion followed by signal propagation in a dispersive medium presents an alternative approach to control the delay time because it is simpler and more controllable. In this paper, a tunable optical delay line with a large time delay up to 650ps based on four-wave mixing (FWM) wavelength conversion in 420m high nonlinearity fiber (HNLF) and dispersion in 8km standard single mode fiber (SMF) is experimentally demonstrated.Our experimental results are in good agreements with the principle.