一、前言在单模光纤通信中,特别是外差法接收时,都希望抑制偏振面的摆动或旋转。另一方面,我们知道,在轴对称单模光纤中,各种外界干扰都容易使偏振面变化。本报告从实践和理论两方面探讨了单模光纤受扭曲时出射端偏振面之变化。关于受扭单模光纤的特性,业已有过一些报导。本报告首先假定单模光纤二个正交HE_(11)模的传输常数不同,试图说明单模光纤受扭后的偏振特性。结果得到了一条与实测特性颇为一致的理论曲线。又通过理论值与测试值比较,证实了能够确定单模光纤二个正交 HE(11)型传 I. Introduction In single-mode optical fiber communication, especially in heterodyne reception, it is desirable to suppress the wobbling or rotation of the plane of polarization. On the other hand, we know that in an axisymmetric single-mode fiber, various external disturbances can easily change the plane of polarization. This report examines the variation of the polarization plane at the exit end of a single-mode fiber, both in practice and in theory. There have been some reports on the characteristics of twisted single mode fibers. This report first assumes that the propagation constants of two orthogonal HE_ (11) modes in a single mode fiber are different, trying to illustrate the polarization characteristics of a single mode fiber after it is twisted. The result obtained a quite consistent theoretical curve with the measured characteristics. And by comparing the theoretical value with the test value, it is confirmed that the two orthogonal HE (11) type transmission