以熊猫型保偏光纤为对象，系统研究了牵引张力和热处理对其双折射的影响。在基于有限元的多物理场建模计算中，引入牵引张力，得到熊猫型保偏光纤双折射随牵引张力增大而线性减小的数值规律。采用白光干涉法实验测量了不同热处理过程对熊猫型保偏光纤双折射的影响。高温下应力区掺硼石英玻璃发生结构弛豫，引起熊猫光纤应力区体积收缩，使双折射增大。通过计算玻璃网络空位缺陷浓度变化得到应力区掺硼石英玻璃结构弛豫引起的形变量和熊猫光纤退火后的双折射，数值仿真结果与实验测量相符。该研究为应力型保偏光纤的设计、制备和双折射调控提供了理论依据。

Taking panda-type polarization-maintaining fiber as the object, the influence of drawing tension and heat treatment on its stress birefringence is systematically studied. In the multiphysics finite element modeling, we introduced the drawing tension during the fiber preparation process into the PMF photoelastic model, and we summarized the numerical law that the birefringence of the panda-type PMF decreases linearly with the increase of the drawing tension. We used white light interferometry to experimentally measure the effects of different heat treatment conditions on the birefringence of PMFs. The structural relaxation induced by boron-doped silica glass at high temperature causes the volumetric shrinkage of the Stress Applying Parts (SAP), which increases the birefringence. The deformation caused by the structural relaxation is obtained from the variation of the vacancy defect concentration of the glass network, and then the birefringence after the annealing of the fiber is calculated. The numerical simulation results are consistent with the experimental measurements. This work provides a theoretical basis for the design, preparation and birefringence control of PMF.