Oscillating soliton molecules induced by strong vector-mode coupling
Jingyi Li, Dong Mao, Qun Gao, Zhiwen He, Yueqing Du, Chao Zeng, Jianlin Zhao
Abstract
Soliton molecules, composed of closely spaced pulses with strong internal interactions, have been in-depth studied in fiber lasers due to their fascinating evolution dynamics and potential applications in high-speed optical communications. Here we demonstrate a type of oscillating soliton molecules in a mode-locked fiber laser constituted by single-mode and polarization-maintaining fibers. Ascribing to the unequal coupling between two orthogonal-polarized vector modes, the constituent pulses of soliton molecules possess different intensities and further result in a dual-roundtrip and large-period oscillation. Numerical simulations reproduce the critical experimental phenomena and show that two vector modes display diverse departing behavior in polarization-maintaining fiber. This work sheds light on the role of strong birefringence on vector solitons, providing a flexible nonlinear system to generate and study oscillating soliton molecules.