Resonant trapping in a fiber with photo-induced gap in wave-number

We show that the nonlinear response of a standard telecom fiber can be exploited to induce a traveling-wave (dynamic) grating by means of illumination with a beat signal. When other two pulses at different frequency are resonant with the grating, and sufficiently intense, they can be trapped as a single localized wave, i.e. a resonance soliton, that leads to cancel the group delay experienced by the pulses in the absence of the grating. This phenomenon is representative of systems that exhibit a gap in wavenumber.