光纤陀螺是干涉型传感器,光的偏振特性影响该传感器的精度,因此需要对光纤的偏振态进行精确的测试.目前国外有些公司出售检偏系统,但所给的指标并不高,而且价格也非常昂贵,国内使用的测试系统一般都为自制,精度普遍不高,实际测量的消光比小于系统的理论消光比.有偏振特性系统的设计和测试结果,却没有系统误差原因的详细分析.针对这一问题,在给出了高精度保偏光纤偏振测试系统的光路结构基础上,对系统中影响消光比的光路误差进行了分析和计算.通过理论分析和计算机模拟计算,得到本系统的消光比在给定的误差范围内可以达到55 dB,能够满足高精度的测量.同时,在计算中得到了e光和o光的透射率,计算结果中棱镜e光的透射率比以往的结果精确2.34%.

Fibe-optic gyroscope is an interferometric sensor, and the characteristic of polarization influences its precision,therefore the polarization state of the fiber need to be tested.At the present,the system of polarization testing is soled abroad,but its index is low,and its price is very high.Accordingly,the testing system used in home is made by ourselves,but its precision is not high universally.At the same time, the tested extinction ratio is smaller than its theoretic value.The design and tested result are given by some companies,yet the reason of the system＇s errors has not analyzed in detail. For this reason, in this article, based on the optical structure of high precision PM fiber polarization detection system,the optical errors that affect the extinction ratio are analyzed and calculated.After theoretically analyzing and calculating by computer simulation,in the range of given errors the extinction ratio can reach 55 dB,which fulfills the high precision measurement.And the transmission ratios of e rays and o rays are obtained by calculation. The transmission ratio of e rays is 2.34% higher than the past results.