四频差动激光陀螺的磁敏感性与最佳工作点

为了减小四频差动激光陀螺(DILAG)的磁敏感性,研究了工作点对磁敏感性的影响.根据理论分析,磁敏感性主要来自于左、右旋陀螺相对比例因子修正的不对称,它与工作点有关,在最佳工作点下为零.通过在DILAG增益管上缠绕线圈产生轴向磁场,调节附着于腔平移镜上的压电换能器的驱动电压改变工作点,得到磁灵敏度随工作点的变化规律.结果表明,DILAG在最佳工作点下对外界磁场不敏感,且在每个工作区存在唯一的最佳工作点.DILAG工作在最佳工作点可以使外界干扰在差动中消除,因而有利于提高其性能.为了保证DILAG工作在最佳工作点,必须改变传统的光强差稳频方式.

Magnetic Sensitivity and Optimal Operating Point of Four-Frequency Differential Laser Gyroscope

In order to reduce magnetic sensitivity of four-frequency differential laser gyro (DILAG), effect of operating point on magnetic sensitivity was investigated. According to theoretical analysis, magnetic sensitivity arises mainly from unequal relative scale factor corrections of left and right circularly polarized gyros. The DILAG,however, is insensitive to magnetic field when operating at the optimal point. Axial magnetic filed was produced by winding coil around gain tube, and operating point was changed by adjusting voltage of piezoelectric transducer affixed to cavity mirror in our experiment. As a result, the curve of magnetic sensitivity versus operating point was obtained. The results showed that DILAG was insensitive to magnetic field at the optimal operating point, which uniquely existed within operating area. Environmental disturbance would be reduced when DILAG was operating at the optimal point. This helped to improve DILAG performance. The conventional frequency stabilization method using light intensity comparison should be changed so as to make sure DILAG operating at the optimal point.