利用声光差频抑制集成光学陀螺背散噪声研究

研究了利用两个声光移频器间的差频抑制谐振式集成光学陀螺中的背向散射噪声.测试了声光移频器的输出特性,结果表明声光移频器输出功率随调制频率变化.测试并说明了两路声光移频器的功率不平衡会影响环形谐振器的谐振曲线深度和陀螺解调曲线的斜率,并最终导致陀螺的测量误差.实验中通过补偿声光移频器的输出功率,有效地克服了声光移频器功率带宽的影响,陀螺零漂从补偿前的0.28 mV降低为0.095 mV.

Research on Suppressing Backscattering Noise in Integrated Optical Gyroscope by Acousto-Optic Difference Frequency Technique

The backscattering noise in resonant integrated optical gyro using the difference frequency between two acousto-optic frequency shifters is studied. The output characteristics of the acousto-optic frequency shifters are tested, which demonstrates that the output power of the acousto-optic frequency shifter varies with the modulation frequency. It is shown that the power imbalance between the two acousto-optic frequency shifters influences the resonant curve depths of the ring resonator and the slopes of the gyro demodulation curves, and eventually leads to gyro measurement errors. The influence of the power bandwidth of the acousto-optic frequency shifter is effectively overcome through compensating the output power of the acousto-optic frequency shifters in the experiment. The zero drift of the gyro is reduced from 0.28mV before the compensation to 0.095mV after the compensation.