Temporal interference of coherent laser pulses in optical fibers

We report on collective effects for the train of optical pulses when a reproduction of the periodical pulse train occurs at some distance in dispersive medium. The reproduction of the initial temporal distribution can be treated as a temporal analog of the spatial Talbot effect. In experiment with a multimode fiber, the group of seven pulses lost its temporal shape converting in one broad pulse at the distance of 1200 m, while continuous train of pulse preserved its temporal structure.