Soliton content of pulses in lossy fibers

This paper studies soliton propagation in fiber with loss using soliton-radiation beat analysis. The input pulse, containing a soliton as well as radiation, is propagated with a standard numerical technique. To analyze the beat note, this paper uses a Gabor transform with a sliding central position along the fiber. This yields spectral information with a spatial resolution essentially equal to the window length, and a spectral resolution determined by the inverse of the window length. From this information, the fractional energy of the soliton is deduced.