Study On Polarization Coupling Mechanism Of Electrode Discharge In Polarization Maintaining Fiber

Polarization coupling is a fundamental phenomenon in optical fiber,which is one of the important factors limiting optical fiber communication.Polarization-coupling fiber is an important performance index to measure polarization-maintaining fiber's performance.Polarization coupling in polarization maintaining fiber is still unavoidable,especially when the polarization maintaining fiber is welded and subjected to transvers pressure.Different from the field of optical fiber communication to avoid polarization coupling problem,in the field of optical fiber sensing,polarization coupling can be used as a measurement and sensing means.The purpose of this paper is to study the polarization coupling mechanism in the polarization maintaining fiber,and to explore the corresponding method to generate the coupling point of the intensity controlled polarization,and to lay the foundation for the realization of polarization coupling.In this paper,several external factors that cause polarization coupling of polarization maintaining fiber are introduced,such as transverse pressure,temperature,bending and external magnetic field,and the polarization coupling method is proposed.Several kinds of polarization coupling systems are introduced in this paper.The advantages and disadvantages of the white-light interferometer system are introduced in this paper,which are used to measure the polarization coupling.Secondly,the polarization coupling mechanism in the polarization maintaining fiber is studied.Three kinds of polarization coupling are analyzed,such as off-axis fusion,fiber deformation and fiber residual twist.The finite element model of viscoelastic fiber and the experimental method are established to analyze the influence of the fiber residual twist on electrode polarization polarization coupling polarization.Finally,based on the mechanism of polarized coupling in the polarization maintaining fiber based on the discharge of the electrode,a polarization weak coupling point is proposed by using the electrode discharge to twist the PM fiber.The temperature field distribution,the relationship between electrode discharge current and electrode discharge temperature,the length of discharge region and the angle of intermediate torsion angle,are used to calculate the polarization coupling intensity of polarization maintaining fiber.By means of the fiber viscoelastic model and the experimental method,three kinds of methods,such as changing the discharge current of the welding machine and changing the discharging time of the fusion splicer,were established.The controllable weak polarization coupling point was created inside the polarization maintaining fiber,and the angle and coupling intensity A corresponding curve relationship.In this paper,the polarized coupling mechanism of polarized fiber in polarization maintaining fiber is proposed by using electrode discharge method.The results show that the controllable weak polarization coupling is produced by controlling the parameters of the fusion splicer using the electrode discharge method.