Full-field characterization of breather dynamics over the whole length of an optical fiber

Full-field longitudinal characterization of picosecond pulse train formation in optical fibers is reported. The spatio-temporal evolution is obtained via fast and non-invasive distributed measurements in phase and intensity of the main spectral components of the pulses. To illustrate the performance of the setup, we report, to the best of our knowledge, the first time-domain experimental observation of the symmetry breaking of Fermi–Pasta–Ulam recurrences. The experimental results are in good agreement with numerical simulations.