Characterization of the resistance ability to external disturbance in single circular polarization optical fiber with multiple stress elements

•Multiple modes coupled equation correlated with the fundamental modes and the higher order modes is established.•Numerical simulation results are compared with the theoretical analysis based on the multiple modes coupled equation.•The ability to resist external disturbance is characterized by the coupling strength between the fundamental mode and the higher order mode. The coupled mode equation correlated with the fundamental modes and higher order modes in the optical fiber with multiple stress elements is established. Polarization transmission property is analyzed and demonstrated based on numerical simulation and theoretical analysis. It is found that the coupling strength between the fundamental modes and higher order modes can be utilized to characterize the ability to resist the external disturbance. The greater the coupling strength is, the stronger the ability to resist the disturbance. When the magnitude of the external disturbance is much small (one magnitude order or less) than the coupling strength, its effects can be ignored. If the magnitude of the external disturbance is comparable with the coupling strength or even greater it will result in significant influence on the polarization transmission. To realize a truly single mode single circular polarization optical fiber with multiple stress elements, the structure with the maximum coupling strength and the optimized stress oscillation amplitude should be employed