机械抖动棱镜式激光陀螺出射光强度特性

针对棱镜式激光陀螺在抖动状态下出射光强度被调制的现象, 系统地研究了机械抖动对棱镜式激光陀螺中光传输轨迹和光电探测器的影响机理. 在对现有棱镜式激光陀螺性能进行分析的基础上, 应用数值模拟和有限元分析方法, 将对称型全反射棱镜纳入四棱镜陀螺的结构设计方案, 并给出了由机械抖动引起的应力双折射和光电探测器位置偏移与出射光强度的一般关系. 结果表明, 机械抖动会使棱镜产生应力双折射, 使激光光路发生改变, 同时造成光电探测器与出射光束产生相对位移, 导致出射光强度幅值产生调制. 使用全对称型的陀螺结构, 选取具有合适折射率的对称型棱镜, 减小探测器与出射光斑中心的相对位移, 可以将出射光强度调制幅值相比原先减小52.63%以上, 显著地改善出射光强度被调制的现象. 此分析结果为提高激光陀螺的可靠性提供了重要参考.

Intensity properties of output light in prisms laser gyro with mechanical dither bias

For the modulation phenomenon of output light intensity in the laser gyro consisting of totally reflecting prisms during its dither bias, the effect of mechanical dither is calculated and analyzed systematically. By the numerical simulation and finite element analysis methods, an analytical expression for the output light intensity of the laser gyro is derived as a function of stress induced birefringence and deviation of photodetector. A new laser gyro type with the symmetic rectangle structure that can improve the stability of optical output is suggested for the first time. The results show that the position assembly accuracy of the photodetector and the stress induced birefringence have a significant effect on light intensity modulation. Reducing the photodetector deviation and using symmetic prisms material with a suitable refractive index, the extent of intensity modulation could be reduced by over 52.63%. The analytic study provides an important reference for improving the quality of output light and the reliability of prisms laser gyro.