同济大学 电子与信息工程学院 信息与通信工程系, 上海 201804
谐振式光纤陀螺（Resonator Fiber Optic Gyroscope, RFOG）的性能是多种误差和噪声共同作用的结果。分析了RFOG主要误差与噪声的产生机理, 建立了各误差与噪声的分析模型, 结合具体陀螺参数, 对误差和噪声的等效旋转速率进行了估算, 对抑制误差和噪声的有关措施进行了数值量化。以RFOG零偏稳定性0.1°/h需求为例, 为抑制背向散射噪声及背向反射误差, 相位调制移频时顺时针和逆时针光波的载波强度残留水平之积需高于112dB; 为抑制克尔效应, 顺时针和逆时针方向的光强差需控制在3.86nW以内; 地磁场方向不确定性引起的陀螺零偏稳定性约为0.7°/h。该工作为RFOG实验研究和工程设计提供了理论指导。
谐振式光纤陀螺 光纤环形谐振腔 误差与噪声 背向散射 resonant fiber optic gyroscope ring resonator error and noise backscattering
Author Affiliations
Abstract
1 College of Electronics and Information Engineering, Tongji University, Shanghai 201806, China
2 Shanghai Aerospace Control Technology Institute, Shanghai 201109, China
3 Shanghai Engineering Research Center of Inertia, Shanghai 201109, China
A resonator fiber optic gyro with the light time-division input and multiplexing output (TDM-RFOG) in the clockwise (CW) and counterclockwise (CCW) directions is proposed. The light time-division input in the CW and CCW directions can effectively suppress the backscattering induced noise. The TDM-RFOG is implemented with the 2 × 2 Mach–Zehnder interferometer (MZI) optical switch. The response time of the fiber ring resonator is analyzed, and it is demonstrated by experiments that light time-division input in the CW and CCW directions can reduce the backscattering induced noise. The suppression effectiveness of backscattering induced noise in the TDM-RFOG is determined by the extinction ratio of the optical switch, so a closed loop is designed to adjust the phase shift difference between the two arms of the MZI optical switch to control the extinction ratio. The method using two arms of the MZI optical switch with twin 90° polarization-axis rotated splices is proposed to make the extinction ratio along both slow and fast axes greater than ?70 dB.
resonator fiber optic gyroscope Mach–Zehnder interferometer backscattering induced noise Chinese Optics Letters
2020, 18(3): 030601
建立适应不同产地相思树化学组分含量的近红外光谱分析模型对预测木材化学组分含量具有重要的意义。 用常规化学法测量了取自广西78个和福建33个相思树样品的聚戊糖含量, 并结合近红外光谱数据用偏最小二乘法建立了广西相思树聚戊糖含量的近红外光谱模型。 校正模型的决定系数R2cv为0.947, 内部交叉验证均方差RMSECV为0.464, 验证模型R2val为0.925, RMSEP为0.455。 为了扩大模型的适用范围, 用福建不同数量样品对该模型进行修正。 结果表明: 在广西模型的基础上加入一个有代表性的福建样品就能大大降低直接用广西模型预测福建样品的误差。 加入3个有代表性的福建样品后能够得到较好的模型。 用该模型预测未参加建模的福建样品, 预测模型的R2val为0.904, RMSEP为0.759。 用4组(每组3个样)不同的福建样品修正广西模型, 用固定的20个未参与修正广西模型的样品来验证, 预测误差略有不同, 表明样品的选择在一定程度上影响着修正模型的质量。
近红外光谱 相思树 聚戊糖 适配性 Near infrared Acacia spp Hemicelluloses Suitability 光谱学与光谱分析
2010, 30(5): 1206
