采用庞加莱几何表象, 从理论上分析了光纤中的线双折射和圆双折射分别对入射光偏振态的调制规律, 同时研究了这两种双折射同时存在的低双折射旋光纤的双折射特性.根据理论分析的调制规律, 提出了一种基于传统分立光学元件测量旋光纤双折射参量的截断法, 可以仅通过消光比的测量和计算获得旋光纤的线双折射和圆双折射参量, 进而可以通过线双折射参量近似计算差分群时延, 且采用该方法的理论计算值与传统方法的测量值吻合.

The rules of birefrngence in the waveguide modulating the state of polarization of the incident lightwave was presented in terms of the Poincare geometrical representation.The polarization characteristic of the optical fibers,in particular of the spun fibers,was analyzed under these modulation rules.A new method for measuring spun fibers was introduced which utilizes conventional discrete optical element only.The differential group delay also can be calculated from the results of this measurement.By the comparing with the conventional measurement value,it is shown that the calculated value of differential group delay has a good agreement with it.