Generation of picosecond pulse train with alternate carrier frequencies using dispersion oscillating fiber

The train of picosecond pulse pairs with alternate carrier frequencies was observed when the train of picosecond pulses was launched into the fiber with sine-wave variation of the core diameter. The effect occurs due! to dispersion oscillations along the fiber length, which result in splitting high-order solitons. In the experiments, the splitting of second-order soliton was observed. The separation between carrier frequencies of output pulses depends on the phase of periodical oscillation of the fiber dispersion. Numerical simulations were madeand show good agreement with the experimental results.