High repetition rate pulse train generation in fibers with linear anomalous dispersion decrement: algorithm for refining the longitudinal dispersion profile of the fiber

Modulation instability (MI) is a fundamental nonlinear effect that triggers instability growth in physical systems. In optics, this effect manifests as the decay of a modulated continuous wave (CW) into a pulse train. The most well-known instances of MI occur in systems described by the nonlinear Schrödinger equation, such as when an initially modulated CW propagates through an optical fiber. We report experimental results on high-repetition-rate pulse train generation achieved by injecting an initially modulated CW into a fiber with longitudinally decreasing anomalous dispersion. This process yielded stable, sub-picosecond pulse trains with repetition rates ranging from 100 to 300 GHz and an optical spectrum width of up to 80 nm (at the -20 dB level). By comparing experimental data with numerical simulations, we propose a method for refining the dispersion profile parameters of such fibers.