【摘要】 光纤中的交叉相位调制将导致非线性双折射，从而引起偏振不稳定性。研究了光纤中线偏振光的入射角度与非线性双折射拍长的关系， 得出了入射偏振光接近快轴时，非线性使双折射增强，拍长变短的结论。这一结果与文献［２］ 的理论相反更多还原

【Abstract】 In optical fibers,cross-phase-modulation will lead to nonlinear birefringence which results in polarization unstability. This paper investigates the relationship between incident angle and the beat length of nonlinear birefringence.The results show that when incident polarization light approaches the fast axle, nonlinearity makes birefringence stronger and beat length shorter.This conclusion is contray to Winful’s theory in reference [2].更多还原