Polarization Domain Walls in Strong Birefringent Fiber Resonators

The formation of domain walls occurs due to a spontaneous symmetry-breaking, connecting two distinct symmetry-breaking solutions and enabling the interchange of two polarization modes. Currently, weakly birefringent fibers are used for generating and examining domain walls. However, since fiber birefringence and other non-idealities have great influence on spontaneous symmetry-breaking, it can be challenging to generate domain walls in strongly birefringent fiber resonators. In this study, a new approach is introduced to forming the domain walls in a strong birefringent fiber resonator. Two sections of polarization-maintaining dispersion-compensating fiber are used to construct a normal dispersion cavity by exchanging the fast/slow axis inside the cavity. The mechanism and evolutionary process of the polarization domain wall arising in the cavity are analyzed. Our numerical results demonstrate that domain walls can form in polarization-maintaining cavities, which has significant implications for enriching the understanding of nonlinear dynamics in resonators.