谐振式微光学陀螺偏置频率调制技术研究

谐振式微光学陀螺(RMOG)是一种基于光学Sagnac效应的新型角速度传感器.提出了基于模拟波形连续线性相位调制技术的偏置频率调制.与传统的双频率锯齿波调制以及数字调制方法相比,偏置频率调制消除了由于锯齿波回扫或数字波形中的台阶效应引入的脉冲噪声.从理论上推导了连续线性相位调制波形参数与陀螺的动态范围和灵敏度的关系,得...     

基于零拍探测和压缩真空光输入增强Sagnac效应

利用量子技术增强Sagnac效应提高陀螺输出精度具有重要的研究意义, 是实现全自主导航的重要途径. 以相干态激光作为输入光源的光学陀螺因真空零点波动使其输出精度限制于散粒噪声极限而难以提高. 为减小真空波动的影响, 提出在激光输入的分束器的另一输入端输入压缩真空光并结合平衡零拍探测技术的方法增强Sagnac效应. 理论分析表明Sagnac效应性能得到有效提升: 干涉输出的灵敏度检测极限和动态范围均随着压缩程度的增加而呈指数级增长. 该方法只需对经典光学陀螺做少量改动就可实现, 是提高光学陀螺输出精度的一种新方法.     

压缩真空光输入和光子计数法增强Sagnac效应

压缩真空光输入和平衡零拍探测可有效增强Sagnac效应,提高陀螺精度;考虑平衡零拍探测的相位精度与相位自身相关,仅在某特定相位能达到最佳灵敏度,设计了一种基于光子计数法提取Sagnac输出相位的方案,并利用贝叶斯理论估计相位.理论分析结果表明,该方法能突破散粒噪声极限,相位精度不再受限于相位自身,且当压缩真空光和相干激光功率相同时,精度在理论上能达到海森堡极限.     

压缩真空光输入和光子计数法增强Sagnac效应（英文）

压缩真空光输入和平衡零拍探测可有效增强Sagnac效应,提高陀螺精度;考虑平衡零拍探测的相位精度与相位自身相关,仅在某特定相位能达到最佳灵敏度,设计了一种基于光子计数法提取Sagnac输出相位的方案,并利用贝叶斯理论估计相位.理论分析结果表明,该方法能突破散粒噪声极限,相位精度不再受限于相位自身,且当压缩真空光和相干激光功率相同时,精度在理论上能达到海森堡极限.     

光纤陀螺

1 前言光纤陀螺是利用Sagnac效应检测旋转角速度的一种光纤传感器。由于光纤陀螺(OFG)具有表1所列的许多特征,因此各国都在积极研究开发下一代陀螺。本文主要介绍OFG的原理、结构及其应用。     

基于光学时延补偿的50 km光纤微波频率传递

报道了利用50 km光纤实现4.38×10~(-15)@1 s和2.80×10~(-18)@65.5×10~3s稳定度的微波频率传递的实验研究.实验系统采用多普勒噪声消除技术,通过在本地端探测往返传递的微波信号相位获得链路上的相位变化信息,并实时控制光延迟调整机构进行补偿.光延迟控制采用压电陶瓷的快速拉伸和慢速光纤温控联合方式,可实现5 ns和千赫兹带宽的光延迟控制,能够实现光纤噪声的长期高精度补偿.与电相位补偿相比,光延迟补偿受微波泄露的影响相对较小,而微波泄露影响在类似系统难以避免,因此这种方式更利于获得高稳定度的频率传递.此外,系统采用变频往返传递消除光寄生反射效应,以及色散补偿光纤减小因色散引起的调制信号衰减等措施,提高了系统的技术指标.     

基于光学-微波同步的低噪声微波产生方法

低噪声微波在冷原子光钟、光子雷达、大科学装置远程同步等领域具有重要的应用价值.本文介绍了一种基于光学-微波相位探测技术的低噪声微波产生方案,利用光纤环路光学-微波鉴相器,将超稳激光的频率稳定度相干传递至介质振荡器.实验采用梳齿相位参考至超稳激光的窄线宽掺铒光纤飞秒光学频率梳,结合光纤环路光学-微波鉴相器和精密锁相装置,将7 GHz介质振荡器同步至光频梳重复频率的高次谐波,同步后的光脉冲序列与微波信号的剩余相位噪声为–100 d Bc/Hz@1 Hz,定时抖动为8.6 fs [1 Hz—1.5 MHz];通过搭建两套低噪声微波产生系统,测得7 GHz微波的剩余相位噪声为–90 d Bc/Hz@1 Hz,对应的频率稳定度为4.8×10^–15@1 s.该研究结果对基于光学相干分频的低噪声微波产生提供了一种新思路.     

三角波调制对谐振微光学陀螺偏置稳定性的影响

谐振式微光学陀螺是一种新型的惯性传感仪器,与传统的机械陀螺与其他光学陀螺相比具有很多理论上的优势。通过分析抑制载波和提高信噪比,深入地研究了三角波调制频率和幅度对谐振式微光学陀螺偏置稳定性的影响。通过理论计算和仿真分析,考虑得到更好的载波抑制效果,调制幅度应选为15.44 V;考虑提高信噪比,调制频率应设为1 MHz。搭建了谐振式微光学陀螺系统,实验测试结果与理论分析吻合较好。此外,采用优化的调制参数,陀螺的偏置稳定性由0.39 ()/s提高到0.18 ()/s(10 s积分时间)。研究结果表明:选择优化的调制三角波参数可以将陀螺偏置稳定性提高一倍,对于其他调制方案,如正弦波相位调制方案,同样可以通过分析载波抑制和信噪比优化调制参数,改善陀螺偏置稳定性。     

三角波调制对谐振微光学陀螺偏置稳定性的影响（英文）

谐振式微光学陀螺是一种新型的惯性传感仪器,与传统的机械陀螺与其他光学陀螺相比具有很多理论上的优势。通过分析抑制载波和提高信噪比,深入地研究了三角波调制频率和幅度对谐振式微光学陀螺偏置稳定性的影响。通过理论计算和仿真分析,考虑得到更好的载波抑制效果,调制幅度应选为15.44V;考虑提高信噪比,调制频率应设为1 MHz。搭建了谐振式微光学陀螺系统,实验测试结果与理论分析吻合较好。此外,采用优化的调制参数,陀螺的偏置稳定性由0.39(°)/s提高到0.18(°)/s(10s积分时间)。研究结果表明:选择优化的调制三角波参数可以将陀螺偏置稳定性提高一倍,对于其他调制方案,如正弦波相位调制方案,同样可以通过分析载波抑制和信噪比优化调制参数,改善陀螺偏置稳定性。     

光纤激光陀螺镜在超短脉冲测量中的应用研究

介绍了采用光纤激光陀螺镜测量超短脉冲宽度、形状、相位时的应用理论．以及相关群速度色散的补偿办法：利用可以自行调节旋转角速度的光纤陀螺镜作为光学延迟线实现旋转角速度的任意连续调整．并在使用归一化的Gerchberg-Saxlon算法中实现过程自动控制、克服了原有测量方法中因时延一定．只能作一次自相关处理．及把时延测量变为路径测量时准确性差和测量精度有限的缺点。利用高精度单光子计数系统对相干光包络进行测量．极大地提高了测量精度．进一步拓宽了超短脉冲在物理、生物、化学以及超高速光纤通信等领域的应用范围.     

A scheme for Sagnac-effect quantum enhancement with Fock state light input

Sagnac effect enhancement can improve optical gyro precision. For a certain input intensity, we suggest that the other input port of beam splitter(BS) should be fed with some quantum light to break through shot noise limit(SNL) to improve Sagnac effect without increasing radiation-pressure noise(NRP). We design a Sagnac effect quantum enhancement criterion(SQEC) to judge whether some quantum light can enhance Sagnac effect and present a Sagnac effect enhancement scheme that utilizing Fock state light and parity measurement technique to extract the output phase. The results of the theoretical analysis show that the maximum sensitivity can be reached at θ = 0, and the phase precision can break through SNL and even achieve Heisenberg limit(HL). When the Fock state average photon number n is far less than coherent state, the minimum measurable angular rate is improved with (2n+1)~(1/2) times, which can deduce shot noise and increase NRP little.     

谐振式集成光学陀螺噪声分析与实验研究

针对目前谐振式集成光学陀螺(IORG)输出检测精度与其理论极限灵敏度存在两个数量级差别的情况,分析了IORG系统中存在的主要噪声源;搭建了基于单光路锁频和单光路输出的IORG噪声分离系统;分别对无光情况下信号检测系统中各部分的噪声以及陀螺静态频率锁定情况下各部分的噪声影响进行了测试与分析;得到了系统的噪声分布情况。实验结果表明:光路噪声以及包括探测器热噪声和散粒噪声的电路固有噪声为系统的主要噪声源。     

谐振腔马赫-曾德尔干涉集成光波导陀螺

研究了光学环形腔中的单方向传输光在光学谐振腔中传输的情况，在系统旋转角速率变化时光束会产生频移，在此基础上，设计出一种具有谐振腔马赫-曾德尔干涉集成光波导陀螺结构，可以方便地检测出系统旋转角速率与方向，其检测精度与光波导谐振腔的品质无关。和萨尼亚克集成光波导陀螺相比较，性能价格比有进一步提高的潜力。     

All-fiber single-mode fiber frequency-modulated continuous-wave Sagnac gyroscope

An all-fiber single-mode fiber unbalanced Sagnac gyroscope is described. The gyroscope is based on optical frequency-modulated continuous-wave interference and consists primarily of four Y-type single-mode fiber directional couplers and a single-mode fiber coil. The rotational velocity of the fiber coil is determined simultaneously by detection of the phase shift of the beat signal. The advantages and limitations of the gyroscope are discussed.     

光纤陀螺漂移稳定控制方法研究

从理论人分析光纤陀螺位相调制器及光源不稳定对整机性能特别是对漂移的影响,通过研究,利用光纤陀螺基频分量、一次谐波及二次谐波分量的组合抑制光纤陀螺噪声,稳定控制光纤陀螺漂移,提高光纤陀螺栓测灵敏度。制作了实施电路。     

Resonator fiber optic gyro using the triangle wave phase modulation technique

Based on the Sagnac effect, resonator fiber optic gyro (R-FOG) has potential as a high accuracy inertial rotation sensor. An R-FOG based on the triangle wave phase modulation technique is proposed in this paper. The slope of the demodulation curve near the resonance dip is found to affect the ultimate sensitivity of the gyro. In order to maximize the slope of the demodulation signal, the parameters of the triangle wave are analyzed. By employing Fourier series and the method of field overlapping, the relationship between the demodulation signal and the resonance frequency deviation is analyzed. The optimum values for the modulation frequency and phase modulation index are obtained. And the relationship between the carrier component and the phase modulation index under analysis in this paper shows that the triangle wave phase modulation technique is more advantageous than the traditional modulation technique in reducing the noise induced by backscattering.     

Reduced minimum configuration fiber optic gyro for land navigation applications

Further cost reduction of the fiber optic gyroscope is necessary in order to meet the economic requirements of land navigation systems. We have previously concentrated on the reduction of the number of splices and component improvements in the open-loop, minimum configuration. Now we eliminate nonessential components and splices. The source-detector coupler is not part of the Sagnac interferometer and serves solely to provide isolation between the broadband optical source and the photodetector. Many commercial laser diodes incorporate a back-facet photodetector to monitor laser intensity. The signal returned from the Sagnac interferometer traverses the laser, is received at this photodetector, and can be distinguished from the laser signal by the bias modulation. Configuring a gyro in this manner eliminates a directional coupler and the separate photodetector as well as up to three fiber splices in an all-fiber gyroscope. A production, open-loop, fiber optic gyroscope has been modified to demonstrate this principal. The gyroscope can be constructed with only two fiber splices and exhibits performance comparable to the conventional minimum configuration.     

Investigation of polarization nonreciprocity in dual-interference fiber optical gyroscope

The dual-interference fiber optical gyroscope (DIFOG) is a novel gyroscope that makes use of both birefringent axes in a polarization maintained fiber to generate two Sagnac interferometers. The Sagnac effect is doubled in the DIFOG, resulting in the same precision for a smaller fiber coil and shorter fiber, so it has some potential applications in miniaturized and low-cost situations. The mechanism of polarization nonreciprocity (PNR) in the DIFOG is investigated and the influence of PNR is analyzed theoretically. Simulation results based on the theoretical analysis indicate that PNR error causes the bias of interference signals and the output of the DIFOG to vary with the inherent nonreciprocal phase that arises from the optical configuration. The experiment verifies the theoretical and simulation results.     

平面环形谐振腔微光学陀螺结构设计与优化

提出具有高群有效折射率的双环级联作为核心元件的谐振式平面光波导陀螺结构, 基于光学Sagnac原理得到了双微环耦合谐振式光学陀螺理论灵敏度与群有效折射率的一般表达式和双环与单环陀螺系统的灵敏度关系, 并由耦合模理论方法得到了双环系统耦合器的两个透射系数对应的群有效折射率变化情况. 在环腔半径R₁=R₂=100 μm、环腔传输损耗系数t₁=t₂=0.95的情况下, 针对环与环之间耦合器和环与波导之间耦合器透射系数对群有效折射率的不同影响, 得到了最大群有效折射率的产生条件. 采用文中参数(R=100 μm, t=0.95)计算的单环谐振式陀螺灵敏度为(10⁴-10⁵)°/h, 而双环级联谐振系统理论灵敏度能够达到10 °/h. 该研究对微环耦合谐振腔在角速度检测上的应用有重要的意义.