Nonlinear dynamics of soliton molecules in a Kerr micro-ring

The optical Kerr micro-ring provides an ideal platform for the study of dissipative optical solitons. Dissipative solitons are localized waves produced by a precise equilibrium between dispersion and nonlinearity, as well as gain and loss. Dissipative brilliant solitons are vulnerable to external noise,but dissipative dark solitons exhibit greater robustness against noise and losses. This study discusses the division of the input pump light field into transverse electric (TE) and transverse magnetic(TM) modes. TE mode generates bright solitons. TM mode forms dark solitons via cross-phase modulation (XPM), which induces a self-focusing effect. The bright and dark solitons bind into a soliton molecule pair through mutual interactions. We scan the entire detuning interval; within the positive small detuning interval, two modes simultaneously generate bright-dark soliton pair Turing roll states. Within the larger detuning interval, the excited Brillouin scattering noise induces a high suppression ratio (SR) between the dark and bright soliton pumps, which is unfavorable for the formation of the bright-dark soliton pair. The system provides a new multi-soliton manipulation scheme for optical communications. The soliton molecule pairs hold major implications for high precision measurement and all-optical controlling fields.