Bandwidth and duration of nonlinear-dispersive similariton

Studying the spectral peculiarities of nonlinear-dispersive similariton, generated in single-mode optical fiber without gain (passive fiber), we reveal that the bandwidth of such a similariton is conditioned only by the initial pulse power. This property of nonlinear-dispersive similariton can be used for the pulse duration measurements at the femtosecond time scale, alternatively to the autocorrelation technique.