机械抖动对机抖激光陀螺稳频装置的影响

Effect of mechanical dither on the laser frequency stabilization unit of dithered ring laser gyro

分析了机抖激光陀螺中偏频系统通过机械抖动对稳频装置施加作用力的影响。此力主要通过沿抖动切线方向调制卡盘组件,并改变环形腔腔长,引起激光频率相对变化达10-7量级。实验表明,激光功率调制量随着卡盘组件质量增大和偏频量增加而增加,从而影响零偏稳定性。提高卡盘在抖动切线方向的刚度,减少其质量或采用丝杆与槽片点接触等技术措施,能减少机械抖动对稳频装置的影响,另外,对机抖陀螺应选择合适的偏频量。

A force was analyzed ,which the mechanical dither of biasing system brought to the laser frequency stabilization unit of dithered ring laser gyroscope. The force mainly pushed and pulled the module in a tangent direction to the mechanical dither and modulated the laser cavity path-length ,which changed the laser frequency of the ring laser gyro to the magnitude of 10^-7 . Experimental results show that the increase of the mass of the module and the dither bias will lead to the increase of laser frequency modulation,which can decrease the zero bias stability of the ring laser gyro. The modulation of laser frequency will be reduced by increasing the stiffness of the module in a tangent direction to the mechanical dither,decreasing the mass of the module or using point contact structure between the drive screw and the grooved mirror. In additional,experimental results show that an appropriate dither biasing is required for dithered ring laser gyro.