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The characteristics of noise in fiber-optic gyros are analyzed quantitatively. Based on its physical characteristics and on autocorrelation function evidence, the noise is modeled as the addition of fractal Brownian motion (FBM) and Gaussian white noise (GWN). The value of self-similarlity parameter H in FBM and the intensity of GWN, sigma(w), in the model are robustly determined with an algorithm based on an orthonormal wavelet transform, which demonstrates well the coexistence of the long- and short-term correlation components of the gyro noise. Moreover, it is revealed that FBM dominates the gyro noise, whereas the GWN is minor. 相似文献
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中高精度光纤陀螺的分形噪音研究 总被引:1,自引:1,他引:0
本文在计算和分析光纤陀螺信号自相关函数的基础上,采用小波变换分析了光纤陀螺的噪音叠加模型,指出中高精度光纤陀螺的主要噪音成份为分形布朗运动(FBM).分析其噪音源并对系统进行改进。 相似文献
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We first introduce optical compensation into the field of interferometric fiber-optic gyroscopes (IFOGs), using the opposite polarity of the disturbance between two orthogonal polarization states to suppress polarization-fluctuation-induced noise. A dual-polarized IFOG, in which the fast and slow axes of polarization-maintaining fiber work simultaneously, is implemented and tested. Interference signals of the two axes are added to achieve optical compensation. Experiments show that the IFOG's sensitivity is effectively enhanced in compensated output: all Allan variance indices are improved, among which bias instability is reduced from 0.335 and 0.227 deg/h(fast and slow axes output, respectively) to 0.061 deg/h. 相似文献
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Bias thermal stability of a fiber-optic gyroscope using polarization-maintaining photonic crystal (PM-PCF) was studied. The thermal sensitivity of birefringence in PM-PCF and polarization cross talking in fiber coil was measured. Using an OCDP method, the polarization cross talking causing phase error of the fiber-optic gyroscope (FOG) was analyzed. The contrast experiment result of the FOGs with the PM-PCF coil and PMF coil showed that using PM-PCF instead of PMF can improve the FOG’s bias thermal stability by about 50 %. 相似文献
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The dominant noises which limit the present sensitivity of the gravitational wave detectors are the thermal noise of the suspended
mirrors and the shot noise. For the third generation of gravitational wave detectors as the Einstein Telescope (ET), the reduction
of the shot noise implies to increase the power stored in the detector at 1 MW level and, at the same time, to compensate
the huge optic distortion due to induced thermal lensing. At low temperature it is possible to reduce both these effects.
However, lowering the temperature of the test masses without injecting vibration noise from the cooling system is a technological
challenge. We review here the thermal noise impact on the ultimate ET sensitivity limit and we discuss possible cryogenic
configurations to cool the mirror. 相似文献
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光纤超声传感器通过检测光纤内传输光的强度、波长、相位、偏振态等参数感知超声波的相关信息.相比于传统的电类超声换能器,光纤超声传感器能够实现宽频带超声波信号的高灵敏探测,且其良好的抗干扰能力和复用性,可有效地提高超声波探测的可靠性和效率,在水下国防安全、生物成像、无损探伤、地震物理模型成像等领域具有巨大的应用潜力.目前,按照传感结构,光纤超声传感器可分为光纤强度调制型、光纤干涉型和光纤光栅型,并在不同方面发挥着各自的优势,均受到关注.本文主要综述了这几种传感器的传感机理、实现方法、发展现状,总结了光纤超声传感器的几个应用领域及面临的科学技术挑战,重点讨论了光纤超声传感器作为一种新技术应用于地震物理模型成像. 相似文献
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The measurement of an extremely small magneto-optical polarization rotation angle with high sensitivity is integral to many scientific and technological applications. In this Letter, we have presented a technique based on Faraday modulation combined with the optical differential method to measure an extremely small polarization rotation angle with high sensitivity. The theoretical and experimental results show that common mode noise is reduced appreciably and signal to noise ratio is enhanced. The effectiveness of this technique has been demonstrated by measuring the Verdet constant of terbium gallium garnet glass and measuring the small polarization rotation angle. A sensitivity of enhancement of one order of magnitude has been achieved using differential detection based on Faraday modulation. 相似文献
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Huaiyong Yu Chunxi Zhang Lishuang Feng Huilan Liu Lingfei Hong Zhichao Jiao 《Optics Communications》2011,284(22):5384-5387
Integrated optical resonance gyroscope (IORG), with the ring resonator fabricated by micro-techniques, has the advantage of miniaturization, integration, and low cost. Theoretical calculation shows its potential ability in getting high sensitivity. However, the current IORG sensitivity is restricted by optical parasitical noises aggravated by involving high coherent laser source. Polarization fluctuation is one of the dominant noise sources in waveguide resonator. The effect on polarization noise in IORG by three main parameters: state of polarization of the input light, polarization-maintaining quality of the waveguide, and temperature fluctuation of the peripheral environment, has been theoretically analyzed and experimentally tested. An improved layout, with a Planar Lightwave Circuit (PLC) acting as both modulator and polarizer, is presented to suppress the polarization noise in IORG. The results show that the bias instability of IORG caused by polarization noise is greatly reduced from 1.57°/s to 0.005°/s. 相似文献
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环境磁场的干扰是影响激光陀螺精度的重要因素之一. 为了减小二频机械抖动激光陀螺的磁敏感性, 推导了环形腔的琼斯矩阵, 其中考虑了非共面角、增益介质、腔损耗、腔镜反射各向异性和应力双折射, 采用矩阵本征问题求解的摄动理论分析了环形腔的偏振态和磁敏感特性. 研究表明, 为了减小激光陀螺的磁敏感性, 应减小非共面角和腔损耗, 增大腔镜的反射各向异性. 腔镜应力双折射究竟会增大还是减小磁敏感性与应力作用主轴、受应力腔镜的位置有关, 此外它还会引起顺时针和逆时针模式之间的偏振非互易性. 磁敏感性与腔失谐近似成线性关系, 导致激光陀螺工作于增益峰值时磁敏感性并非最小. 这些结果对减小二频机械抖动激光陀螺的磁敏感性具有较好的指导意义.
关键词:
激光陀螺
磁敏感性
椭圆度
琼斯矩阵 相似文献
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We characterize theoretically and experimentally the degradation of polarization entanglement in a fiber-optic entanglement distribution system where one of the optical fibers is exposed to the effects of polarization mode dispersion (PMD). We show gradual reduction of entanglement with increasing PMD and find that the highest PMD tolerance is achieved when the bandwidth of the pump used to generate the entangled photons in a χ((3)) process is approximately half the bandwidth of the quantum channels. 相似文献
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A double fiber-optic Mach-Zehnder interferometer for sensing magnetic fields is devised using two polarization maintaining single-mode fibers. This sensor achieves not only highly sensitive performance but also excellent immunity from temperature disturbance. The sensitivity attains 243 deg/mT (mT=10-3N/A) for the sensing part of the 5 cm long fiber. 相似文献
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Jamal T. Manassah 《Physics letters. A》1985,113(3):151-153
This paper explores the possibility of using optical pulses in laser gyros. It is shown that solitons, produced in resonant medium, could conceivably be used in tandem with ultrafast time measurement techniques to produce gyros with rotation sensitivity of 10?7 rad/s. 相似文献
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The intensity and position of the coupling points in high birefringence(Hi-Bi)fibers can be detected effectively using distributed polarization coupling(DPC)detection.The detection sensitivity can decrease due to mechanical vibration disturbance and environment noise.Thus,a method based on empirical mode decomposition is proposed to detect weak mode coupling points.The simulation and experimental results illustrate that the proposed method can suppress the noise effectively and improve sensitivity significantly.The method can identify coupling points as weak as-60 dB embedded in noise automatically and effectively.The algorithm is applicable for DPC,and the experimental sensitivity is improved by 10 dB. 相似文献
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一种具有声低通滤波特性的无源零差光纤水听器 总被引:2,自引:1,他引:1
报道了一种新颖的具有抗混叠功能的无源零差迈克耳孙型光纤水听器.它由一个普通的芯轴型光纤水听器和一个圆柱型亥姆霍兹共振器构成.在驻波罐中对其声压相位灵敏度频响进行了测量,结果表明该光纤水听器具有较好的声低通滤波特性,能有效地抑制声信号中的高频成分,从而实现抗混叠滤波.该光纤水听器的低频声压相位灵敏度主要由传感光纤长度和弹性增敏层的物理特性决定,约为-159 dB(0 dB=1 rad/μPa).在1150 Hz附近出现了一个共振峰,这主要由圆柱型亥姆霍兹共振器的声学特性决定.1150~2280 Hz频段内的灵敏度衰减率约为50 dB/倍频程,1500 Hz以后的灵敏度衰减量大于10 dB.这对于提高我国未来声纳系统的抗干扰能力具有十分重要的意义. 相似文献