中文摘要：

提出了可用于四频差动激光陀螺法拉第室的永磁体双磁环结构，用以产生较强且均匀的轴向磁场。推导了永磁体磁环轴线上磁场分布的解析式，理论并实验证明了该解析式的正确性。引入磁场均匀度概念，提出了类亥姆霍兹线圈的双磁环结构，模拟了磁环间距对磁场分布的影响，数值计算了不同均匀度下双磁环结构的磁场分布特征。在此基础上，针对四频差动激光陀螺法拉第室的要求，给出了适用的设计方案。

英文摘要：

A dual-ring permanent magnets structure is presented, which can be used as Faraday cell in four-mode differential laser gyro so as to provide appropriate intensity and axial uniform magnetic field. The analytic expression of the magnetic filed distribution along the ring magnet axes is deduced, which is proved thereafter theoretically and experimentally. The conception of magnetic homogeneity is introduced. The distribution curve of the dual-ring magnets is simulated with different intervals and the characteristics of magnetic field distribution are calculated in given homogeneities. In the end, an appropriate design scheme of Faraday cell in four-mode differential laser gyro is proposed.