论文部分内容阅读
基于Sagnac效应的光学陀螺通常可分为干涉式光学陀螺(IOG)和谐振式光学陀螺(ROG)。IOG中最具代表性的干涉式光纤陀螺(IFOG)现在已完全产品化,其角速度传感精度已接近激光陀螺(LG)。而ROG中最有发展潜力的则是集成光学陀螺,它可以利用现在高度发达的微电子技术将无源环形谐振器(PRR)、耦合器、偏振控制器、调制器件和信号处理电路集成于单个硅基片上,在保证陀螺精度的情况下,可使成本大幅降低,是未来高精度、低价格光学陀螺的一个发展方向。根据Sagnac效应及谐振腔理论,PRR的顺逆时针方向的谐振频率差正比于陀螺角速度的大小,因此精确的检测与跟踪顺逆时针谐振点即为谐振式光纤陀螺角速度检测的基本原理。目前,IOG的检测方法主要集中在基于相位调制器的调相谱(PM)法,且取得了较大的进展,而调相谱法的调制系数约等于1,从调制原理上属于频率调制范畴,与频率调制相对应的另一种调制方法即波长调制方法未见深入研究。本论文从理论上研究了波长调制情况下的谐振式光纤陀螺检测方法,给出了解调曲线的数值描述公式,通过实验得到1Hz锁频精度,需要保证0.1uV的电压检测灵敏度。
Optical gyros based on the Sagnac effect can be generally divided into interferometric optical gyros (IOG) and resonant optical gyros (ROG). The most representative interferometric fiber optic gyroscope (IFOG) in IOG is now fully commercialized and its angular velocity sensing accuracy is close to the laser gyro (LG). One of the most promising ROGs, however, is the integrated optical gyroscope, which integrates passive ring resonators (PRRs), couplers, polarization controllers, modulation devices, and signal processing circuits in a single, highly developed microelectronics technology On the silicon substrate, under the circumstance of ensuring the accuracy of the gyro, the cost can be greatly reduced, which is a development direction of the high-precision and low-cost optical gyro in the future. According to the Sagnac effect and resonant cavity theory, the difference between the clockwise and counterclockwise resonant frequencies of the PRR is proportional to the angular velocity of the gyroscope. Therefore, the accurate detection and tracking of the clockwise and anticlockwise resonant points are the basic principles of the resonant gyroscope angular velocity detection. At present, the detection methods of IOG mainly focus on the phase modulation spectrum (PM) method based on the phase modulator, and great progress has been made. The modulation factor of the phase modulation spectrum method is equal to about 1, which belongs to the frequency modulation category from the modulation principle , Another modulation method corresponding to the frequency modulation, that is, the wavelength modulation method has not been further studied. In this dissertation, the resonant FOG detection method under the condition of wavelength modulation is theoretically studied, and the numerical description formula of the demodulation curve is given. The 1 Hz frequency-locking accuracy is obtained through experiment, and the voltage detection sensitivity of 0.1uV needs to be guaranteed.