Stripe Soliton in All-Fiber Lasers

Stripe solitons (SSs), the special localized wavepackets exhibiting periodic modulations, are identified in condensed matter physics and nonlinear science. Here, giant-chirp and chirp-free SSs in all-fiber lasers are demonstrated composed of single-mode fiber and polarization-maintaining fiber. The chirp property of SSs depends on the cavity dispersion while the stripe period relies on the fiber birefringence. Theoretical and numerical results coincide with experimental findings, revealing that the filtering and frequency shift of two vector modes is governed by the mode coupling related to birefringence and the nonlinear coupling induced by the phase modulation, respectively, which disrupts their complementarity and ultimately leads to modulation of the overall spectrum. With the aid of the saturable absorption and cross-phase modulation effects, the multi-color pulses synergistically overlap, giving rise to the unique SSs. These results present a simple approach for generating chirp-controllable SSs in all-fiber lasers, which is crucial for applications in difference frequency generation and soliton physics.