基于三角波调相谱技术的谐振式集成光波导陀螺(RIOG)信号检测,光波相位调制引入的频谱分量所带来的光学噪声成为限制陀螺性能提升的主要因素。结合光波在三角波相位调制下的频率变化特性和波导谐振腔的光传输特性,给出了三角波调制下的同步解调信息;依据三角波调制下对背向散射噪声抑制的幅度调制参数和系统最大灵敏度工作点的频率调制参数,结合多光场叠加原理,理论仿真分析了谐振谱不同谐振区的输出脉冲噪声,这种脉冲噪声将对工作于不同调制频率下顺逆时针传输光波的信号采集区带来干扰;搭建了基于二氧化硅波导环形谐振腔的陀螺实验系统,分别测试了激光扫描下谐振腔不同谐振区的脉冲噪声和激光频率锁定在谐振腔谐振点时的脉冲噪声,与理论分析一致。分析结果表明,RIOG采用的三角波调相谱信号检测技术存在无法克服的脉冲噪声,针对不同要求的RIOG,给出了相应的调制技术方案,这为RIOG的工程化和性能优化提供了技术参考。

For the resonator integrated optical waveguide gyroscope (RIOG) using triangle wave phase modulation, the optical noises introduced by the phase modulation have become the main factor limiting the performance improvement of the gyroscope. The synchronous demodulation information under triangle wave phase modulation is got, refering to the light wave frequency characteristic and light transmission property of the resonator. According to amplitude parameter for backscattering noise suppression and frequency parameter for the maximum sensitivity working point, and considering multi-light fields superposition principle, the output pulse noises in the different resonance regions are simulated. The pulse noises take serious impact on signal acquisition areas of clockwise and counterclockwise light wave using different modulation frequencies. The gyroscope experiment system based on SiO2 resonator is set up. Under the two different conditions of laser free running and frequency locking, the pulse noises are tested respectively, which are consistent with the theoretical analysis. It’s obvious that the pulse noises can’t be eliminated completely in the RIOG using triangle wave phase modulation. According to the requirements of RIOGs, the corresponding modulation scheme are given, which provide the technical references for engineering and performance optimization of RIOG.