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 共查询到19条相似文献,搜索用时 125 毫秒
1.
光纤干涉型传感器原理及其相位解调技术   总被引:3,自引:0,他引:3  
光纤干涉型传感器是由于外界信号作用到干涉仪上,引起干涉信号相位的变化,通过对相位的解调来反应外界信号。介绍了光纤干涉型传感器的结构及其原理,并对各种干涉型传感器的相位调制与解调技术的优缺点进行了分析。  相似文献   

2.
基于光频调节的干涉型光纤水听器相位补偿检测方法   总被引:5,自引:0,他引:5  
提出了一种基于光源频率调节的干涉型光纤水听器主动相位补偿的信号检测方法。详细介绍了该方法的基本检测原理,对信号解调误差进行了理论分析与仿真。为了验证该方法的可行性,搭建了实验系统,并编写了实时的信号采集、处理程序,对某一干涉型光纤水听器的声压灵敏度进行了测试。在频带20 Hz-1.3 kHz上,平均声压灵敏度为-162.2 dB(0 dB=1 rad/μPa),波动小于±0.8 dB,与采用相位载波调制解调方法测量的结果基本吻合。实验结果证明该方法是有效的。由于传感部分不含有源器件,便于实现全光纤化,且解调算法简单、检测频带宽,该方法能被广泛应用到各种干涉型光纤传感器的信号检测当中。  相似文献   

3.
提出一种干涉型光纤传感器小相位检测的多值抽样方法,消除了干涉型光纤传感器输出信号的衰落,使检测相移可达到10~(-5)rad,接近散粒噪声极限。  相似文献   

4.
干涉型光纤传感器的消偏振衰落技术研究   总被引:1,自引:0,他引:1  
本文对消除干涉型光纤传感器信号偏振衰落的偏振分集接收PDR(Polarization Diversity Receiver)技术进行了理论分析.通过三态PDR方式,对输出的最大有效幅度信号进行选取,能够避免传输光偏振态变化导致干涉信号完全衰落的现象,使干涉信号有效幅度在一定范围内变化.采用基于反正切计算的相位生成载波PGC(Phase Generated Carrier)解调技术的相位测量结果不受由于偏振衰落导致干涉信号有效幅度变化的影响.提出结合三态PDR方式和基于反正切计算的PGC解调技术消除偏振衰落问题的影响,实现干涉型光纤传感器中相位信号的理想解调.  相似文献   

5.
用于干涉型光纤传感器的相位生成载波解调技术   总被引:13,自引:2,他引:11  
黄建辉  曹芒  李达成  程晓辉 《光学技术》2000,26(3):228-231,234
相位生成载波技术是用于光纤传感器中很重要的一种信号解调方法。简要说明了相位生成载波调制的原理和两种基本的调制方法 ,着重介绍了相位生成载波调制信号的解调方法 ,包括 :零差法、伪外差法和合成外差法 ,并对以上各种方法进行了分析比较。对相位生成载波技术在干涉型光纤传感器中的应用作了详细的介绍。针对现在最有希望用于智能结构的光纤布拉格光栅传感器 ,介绍了相位生成载波技术在这方面的应用。  相似文献   

6.
周效东  周文 《光学学报》1998,18(6):73-778
对干涉型光纤传感器的分集检测消偏振衰落技术进行了新的理论分析,提出了将各种信号平方后相加的信号处理方式,使之能实现单元及阵列的实时消偏振衰落信号检测。计算了这一信号处理方式可能引起的幅度最大波动,并得出三路检测偏是分集检测的一个合适取值的结论。根据理论分析,在马赫-陈德尔干涉仪上进行实验研究取得了较好结果,并设计了用于阵列的分集检测实现方式。  相似文献   

7.
关于光纤水听器灵敏度的讨论   总被引:10,自引:1,他引:9       下载免费PDF全文
倪明  张仁和  胡永明  孟洲 《应用声学》2002,21(6):18-21,17
本文先简略介绍了干涉型光纤水听器的基本原理与检测信号的基本方法,由此给出了光纤水听器相位归一化灵敏度、相位灵敏度、电压灵敏度的定义。在分析它们的物理意义以及相互之间关系的基础上,给出一组能反映它们对应关系的一组数据,以及一光纤水听器探头频率响应曲线。  相似文献   

8.
基于迈克尔逊干涉的光纤弯曲传感器   总被引:3,自引:1,他引:2  
林巧  陈柳华  李书  吴兴坤 《光子学报》2011,40(2):251-254
设计并研制了一种新型的基于迈克尔逊干涉的光纤弯曲传感器.该光纤弯曲传感器由两根光纤组成的光纤带固定于弹性弯曲结构上来产生迈克尔逊干涉信号,用光纤折射率匹配液填充微型腔,并施加音频振荡信号对相位干涉信号实现低频调制.采用相位生成载波技术对相位干涉信号进行调制和解调,实现了对曲率变化高精确度的检测.实验测试了该光纤弯曲传感...  相似文献   

9.
林巧  陈柳华  李书  吴兴坤 《光子学报》2014,40(2):251-254
设计并研制了一种新型的基于迈克尔逊干涉的光纤弯曲传感器.该光纤弯曲传感器由两根光纤组成的光纤带固定于弹性弯曲结构上来产生迈克尔逊干涉信号,用光纤折射率匹配液填充微型腔,并施加音频振荡信号对相位干涉信号实现低频调制.采用相位生成载波技术对相位干涉信号进行调制和解调,实现了对曲率变化高精确度的检测.实验测试了该光纤弯曲传感器的相位干涉信号与光纤带弯曲曲率的关系,并与理论分析对比.结果表明该光纤弯曲传感器具有43.96 rad/m-1的灵敏度及0.004 m-1的高分辨率.  相似文献   

10.
研究了偏振分集技术消除干涉型光纤传感器中偏振衰落问题的基本原理及实现方法.理论分析表明,偏振二分集可大大缓解偏振衰落.搭建光纤传感系统对偏振二分集技术进行了实验验证,实验中单路最小可视度接近0,而偏振二分集得到的最小可视度为0.4.实验结果表明系统采用的相位载波调制解调技术实现了信号的稳定检测.  相似文献   

11.
提出了一种光纤声发射传感器并构建传感系统实现变压器局部放电在线监测,利用传感光栅体积小,重量轻,灵敏度高和抗电磁干扰的特点,将传感器置于变压器内部实现局部放电声发射信号的测量。研究了传感光栅实现声发射应力波测量的机理,声发射信号引起传感光栅反射光谱发生漂移,导致特定频点处反射光强发生变化,通过反射光强的变化实现声发射信号的测量。构建声发射传感系统实验模型并提出了一种系统性能优化策略,使系统工作在传感光栅反射光谱上升或下降沿的半峰值频点处,从而保障传感系统具有良好的线性输出特性;研究传感系统工作点稳定技术,设计信号反馈回路自动跟踪反射光谱的漂移,保证系统稳定工作在传感光栅半峰值频点处,消除温度变化对传感系统测量精度的影响。将封装好的传感器用于变压器局部放电现场检测,结果表明,光纤光栅声发射传感器与压电传感器相比具有灵敏度高、动态范围宽等优点,可以实现变压器局部放电在线监测。  相似文献   

12.
The feasibility of sapphire fiber-optic sensors based on evanescent wave absorption spectroscopy in the infrared range for quantitative determination of water content in polar organic solvents has been investigated. Evanescent wave absorption spectra of sapphire fiber-optic sensors in glycerol, ethanol, and glycol with different water concentrations obtained and analyzed, respectively. Evanescent absorbance of the sensors in those organic solvents has been utilized to implement for in situ monitoring water concentration in organic solvents. The evanescent absorbance of sensors in glycerol and glycol has been found to vary linearly with water content in the range 0–30 % and in ethanol in the range 0–10 %, respectively. The fiber-optic sensors based on evanescent absorbance for monitoring water concentrations in those organic solvents are acceptably accurate, cost-effective, and reliable. Some methods to improve the accuracy of predicated water content in those organic solvents are also suggested. Overall, the results demonstrate that the sapphire fiber-optic sensor based on evanescent absorption spectroscopy is a promising candidate for prediction of water content in polar organic solvents in on-line and remote situation.  相似文献   

13.
一种基于外差探测的光纤Bragg光栅温度传感器   总被引:1,自引:1,他引:0       下载免费PDF全文
提出了一种基于光纤Bragg光栅的温度传感器,阐述了光纤Bragg光栅的温度传感机理,用2个相同的光纤Bragg光栅构成折叠式Mach Zehnder(M Z)干涉仪,其中一个光栅作为参考臂,另一个作为传感臂:采用外差探测技术来测量外界的温度物理量。当温度发生变化,Bragg光栅的波长也随之改变。外差探测用来探测传感臂和参考臂由于温度变化引起的输出信号的频率差异。对其动态测量范围和灵敏度也进行了分析。  相似文献   

14.
The performance of a two-dimensional heterodyne detection technique in optical coherence tomography (OCT) was studied. This technique, which is based on the frequency synchronous detection method, enables the use of an imager such as a charge coupled device (CCD) camera as a heterodyne sensor array, so that horizontal cross-sectional image can be acquired in real time without lateral scanning. OCT measurements of scattering media including a biological object were demonstrated. To evaluate the influence of phase fluctuations on the present technique, we measured and analyzed the statistical relative-standard-deviation of heterodyne signal intensity as a function of the random phase shifts between two consecutive CCD frames. Practical limitations in the signal stability and possible solutions are discussed.  相似文献   

15.
An experimental study was conducted to investigate the applicability of fiber-optic acoustic sensors to detect internal flaws in polymeric materials. A polarimetric fiber-optic sensor embedded in a plexiglass model received the acoustic signals generated by an ultrasonic transducer. It is shown that proper control of the polarization and phase of the optical beam is required to obtain meaningful results from the amplitude of the fiber-optic sensor signal. The sensor has shown promising results in determining acoustical properties of plexiglass and locating internal defects. The attractive feature of this sensing scheme is that the optical fibers are not modified prior to embedding. Therefore, they preserve their mechanical properties which makes the embedding process much easier.  相似文献   

16.
Yuan L  Yang J 《Optics letters》2008,33(16):1780-1782
A tunable Fabry-Perot-resonator-based fiber-optic white-light interferometric quasi-distributed sensing system permitting absolute length measurement in a remote reflective sensor array is proposed and demonstrated. The sensor reflective signals characteristics have been analyzed, and the relationship between light signal intensities and sensors number was given for multiplexing potential evaluation. The proposed sensing scheme will be useful for the measurement of strain distribution. An important application could be deformation sensing in smart structures. Experimentally, a four-sensor array has been demonstrated.  相似文献   

17.
In this study, we explored the feasibility of developing two types of fiber-optic temperature sensors that can measure the temperature of water. One uses a thermochromic material such as Lophine, whose optical absorbance changes according to the thermal variation. The other uses a thermochromic pigment that gradually loses its own color through heat absorption. We measured the change in the intensity of the reflected light, which was due to the variation of the optical property of Lophine and pigments, with thermal variation. The relationship between the temperature of water and the output signal of the fiber-optic sensors was also determined. The fiber-optic temperature sensor using Lophine provided a relatively broad range of temperature measurement with low sensitivity, whereas the fiber-optic temperature sensor using a thermochromic pigment offered a high sensitivity in a narrow range of temperature measurement.  相似文献   

18.
Peng W  Banerji S  Kim YC  Booksh KS 《Optics letters》2005,30(22):2988-2990
A dual-channel fiber-optic sensor based on surface plasmon resonance (SPR) for self-referencing refractive-index measurements has been proposed. Most applications of fiber-optic SPR sensors are designed to measure the refractive index of a liquid or gas sample by measuring the signal from a single surface, the sensitivity and stability of which is easily affected by the fluctuation of external environmental conditions. We have designed a dual-channel fiber-optic surface sensor with two independent SPR signals from two areas of the same probe. A prototype sensor was fabricated and characterized. The preliminary experimental results demonstrate the characteristic responses of both SPR signals from two channels that independently correspond to the refractive index changes in the liquid samples with which they are in contact. The design could be extended to a multichannel sensor with further developments. The experimental results confirmed that one channel can be used as a reference sensor that could compensate for unexpected changes in bulk refraction or temperature and develop this sensor as a practicable high-sensitivity biosensing device.  相似文献   

19.
为了避免机载系统故障诊断与重构中单纯增加余度数目所带来的问题,针对电传飞控系统中应用较多的位移传感器,提出了一种基于特征的检测电路、检测方法以及信号重构方案。方案基于位移传感器工作时两次级线圈回路电压和值恒定的特征,实现了对初级、次级回路的一次断线检测,在检测到次级线圈一次断线时,又利用正常工作特征并根据另一次级线圈所获得的信息对断线信号进行重构。分析和测试表明,所提出的位移传感器故障检测以及重构算法仅需增加极少的硬件电路,且检测及重构方法实时性高,在不增加传感器余度数目的条件下,能大大提高系统的可靠性。  相似文献   

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