Optimal frequency conversion in the nonlinear stage of modulation instability

We investigate multi-wave mixing associated with the strongly
pump depleted regime of induced modulation instability (MI) in optical
fibers. For a complete transfer of pump power into the sideband modes, we
theoretically and experimentally demonstrate that it is necessary to use a
much lower seeding modulation frequency than the peak MI gain value.
Our experiment shows that, at such optimal modulation frequency, a record
95 % of the output pump power is frequency converted into the comb
of sidebands, in good quantitative agreement with analytical predictions
based on the simplest exact breather solution of the nonlinear Schr¨odinger
equation.