双纵模自偏频激光陀螺稳频技术研究

The double longitudinal modes reciprocal bias laser gyros is a novel scheme with zero lock-in, solid-state, linear polarization, there is a huge potential application value. The frequency stabilization technology is core support technology for research on double longitudinal modes reciprocal bias laser gyros. combined with the principle of lasing third-order perturbation, the mathematic model of the double longitudinal modes reciprocal bias laser gyros is proposed, the mechanism of reciprocal bias and stable working conditions of double longitudinal modes reciprocal bias laser gyros is studied. A novel double longitudinal modes reciprocal bias frequency stabilization scheme of laser gyros is proposed. Through the high speed digital circuit, the double longitudinal modes reciprocal bias stabilized control system of laser gyros is designed. Considering the weak of the double longitudinal mode small jitter modulation signal and the required of high frequency stabilization accuracy for double longitudinal modes reciprocal bias laser gyros, by adaptive algorithm from laser gyro output signal to extract frequency stabilization feedback signal is proposed, and from optimization of frequency stabilization controller and improve the frequency stabilization feedback signal sensitivity to improve frequency stabilization precision. Finally, the detection system of the double longitudinal modes reciprocal bias laser gyros is proposed, and the stabilized accuracy and related technical indicators of the double longitudinal modes reciprocal bias laser gyros is evaluated. The research to promote the development of a new generation technology of laser gyros has an important value.

双纵模自偏频激光陀螺是一种全新的零闭锁、全固态、线偏振激光陀螺方案，蕴藏着巨大的潜在应用价值。双纵模自偏频稳频技术是双纵模自偏频激光陀螺研究的核心支撑技术。本研究拟通过激光振荡三阶微扰理论建立双纵模自偏频激光陀螺数学模型，研究双纵模激光陀螺产生自偏频的机制以及稳定工作的条件。提出了一种新的激光陀螺双纵模自偏频稳频方案，并拟通过高速数字电路设计双纵模自偏频激光陀螺稳频控制系统。考虑到双纵模小抖动调制信号的微弱性以及双纵模自偏频激光陀螺需要较高稳频精度的要求，我们拟通过自适应算法从双纵模自偏频激光陀螺输出信号中提取稳频反馈信号，从优化稳频控制器和提高稳频反馈信号灵敏度两方面提高双纵模自偏频激光陀螺的稳频精度。最后，我们建立一套双纵模自偏频激光陀螺检测系统，对双纵模自偏频激光陀螺稳频精度及相关技术指标进行评估。本项目的研究对推动新一代激光陀螺技术的发展具有重要的价值。

双纵模自偏频激光陀螺是一种全新的零闭锁、全固态、线偏振激光陀螺方案，蕴藏着巨大的潜在应用价值。本项目基于激光振荡三阶微扰理论建立双纵模自偏频激光陀螺的理论模型，通过计算模拟获得了激光陀螺双纵模自偏频的稳定工作条件，并根据双纵模光强调谐特性提出了双纵模自偏频稳频控制方案，基于FPGA设计双纵模自偏频稳频控制系统及检测系统。主要结果如下：(1)直接从现有Lamb半经典理论，通过数值模拟并不能预示实验中所观察到的双纵模自偏频现象。当假定关系位相角为常数时，通过计算模拟获得与实验完全吻合的自偏频现象，并指出激光陀螺自恰方程组中的关系相位角项是引起自偏频现象的主要原因，自偏频量大小与转速无关，影响自偏量的主要因素是纵模相位差、稳频工作点和相对激发度。(2)由三阶饱和系数的非线性引起双纵模光强调谐曲线存在三个极值点，采用小抖动稳频技术可以使双纵模稳定在相对谱线中心处于非对称的极值上，在该稳频工作点上两纵模对的自偏频量大小相等，可以在现有激光陀螺读出系统上获得稳定的输出。(3)采用24bit的高精度ADC以及RLS自适应相敏解调技术，在腔长为0.45m的全反射棱镜式激光陀螺上实现了双纵模自偏频稳频，其稳频精度达到了10-10量级，满足了双纵模自偏频激光陀螺的使用要求。本项目提出的统一表达形式的相向行波正则模函数避免了Lamb半经典理论复杂的公式推导，并获得了原本只有在驻波激光器中才出现的关系相位角项。并通过该关系相位角项初步解释了实验中所观察到的自偏频现象，获得了双纵模自偏频的稳定工作条件及影响因素，本项目的研究为双纵模自偏频激光陀螺技术的发展指明了方向，为高精度稳频技术的应用提供了重要参考。