Polarization domain walls in strong birefringent fiber resonators

Domain walls form through a spontaneous symmetry-breaking, connecting two distinct symmetry-breaking solutions and enabling the interchange of two polarization modes. Currently, weakly birefringent fibers are employed for generating and examining domain walls. However, it remains challenging to generate domain walls in strongly birefringent fiber resonators since spontaneous symmetry-breaking is very sensitive to fiber birefringence and other non-idealities. In this study, we introduce a new approach 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 besides the polarization-independent cavity, domain walls can form in polarization-maintaining cavities as well, which has significant implications for enriching the understanding of nonlinear dynamics in resonators.