微型光学陀螺仪中声表面波声光移频器的研究

Research on surface acoustic wave acoustooptic frequency shifter for a micro optic gyro

微型光学陀螺仪是基于Ｓａｇｎａｃ效应，采用先进的集成光学技术研制的新型光学陀螺仪。研制微型光学陀螺仪的关键在于用频率调制来实现频率伺服，对主要误差进行有效抑制，实现高精度Ｓａｇｎａｃ频差测量。声表面波声光移频器正是解决上述技术关键的一个集成光学核心器件。针对微型光学陀螺仪对声表面波声光移频器所提出的衍射效率为３％～５％，频移范围±３００ｋＨｚ，短期频率稳定度优于１０－８这些特殊要求，依据声光理论进行了分析与特殊设计。采用平面集成光学工艺，在Ｋ８玻璃基片上研制出声表面波声光移频器。实验结果表明，该器件已初步满足设计要求。

The micro optic gyro (MOG) is a new optic gyro based on Sagnac effect using advanced integrated optic technology. The key technologies in development of MOG are the frequency modulation technology for frequency servo and elimination of main gyro error, and the measurement of Sagnac frequency difference with high accuracy. The key to solve these problems is adopting the acoustooptic (AO) frequency shifter. Theoretical analysis and design based on AO theory are performed for special requirements of MOG. The requirements are that acoustooptic diffraction efficiency is 3%￣5%, frequency shift is ±300kHz , and frequency stability in shorttime is less than 10 -8 . The AO frequency shifter was made on K8 glass by means of planar integrated optical technique. Experiment results show that its main characteristics can satisfy the design requirements.