共查询到19条相似文献,搜索用时 109 毫秒
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基于信号自相关原理的光纤光栅数字解调方法 总被引:4,自引:3,他引:1
为满足工程测试领域对光纤光栅波长漂移高分辨探测技术的需要,提出一种基于信号自相关原理的新型光纤光栅数字解调技术.该技术在可调谐滤波法的基础上,通过对信号序列采用自相关分析以实现对波长漂移的测量以及对传感光栅反射谱形状的识别,能够有效克服噪音对信号的影响.仿真结果表明:光纤光栅自相关数字解调方法可以准确测量光纤光栅波长的漂移,适用于传感光栅具有相同波长的变化范围. 相似文献
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为了实现光纤光栅传感器在可穿戴系统中的应用,提出了一种基于硅基光子集成芯片的可穿戴光纤光栅传感解调系统。基于比利时iSiPP50G工艺的光子集成芯片由4×1长波长VCSEL阵列、1×8阵列波导光栅、2×2 MMI耦合器、4×1光纤光栅耦合器阵列、Ge-on-Si波导光电探测器、直波导和弯曲波导等组成。在完成对VCSEL光源金线键合和光子集成芯片光纤耦合封装的基础上,设计了手环式解调电路,对人体温度和心音信号进行了实时测量。实验结果表明:解调系统的动态波长检测范围为1 540 nm~1 560 nm,波长分辨率为0.08 pm,解调精度为5 pm,温度监测范围为35℃~42℃,误差为±0.1℃;可检测50 Hz~100 Hz频率范围内的心音信号,可识别出第一心音和第二心音,并计算出心动周期、心率、第一心音时限、第二心音时限和心力等特征参数。 相似文献
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传统的匹配光纤布拉格光栅型光纤光栅波长解调系统具有波长匹配精度低、调节困难和动态测量范围小的缺点。为了克服上述缺点,采用波长可调谐高斯型滤波器代替传统匹配光纤光栅,提出了一种新型的光纤光栅波长解调技术。建立了基于高斯型滤波器的光纤光栅振动解调系统。对不同频率和振幅的周期性振动进行了解调实验。发现当选择合适带宽的滤波器时,透过滤波器的光功率随压电陶瓷上所加电压信号同步且高保真地变化,表明该系统对振动信号实现了有效的解调。该系统同时具有响应速度快、物理结构简单、动态测量范围大的优点。 相似文献
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A new type of optical fiber hydrophone is constructed with a fiber Bragg grating (FBG) based on the intensity modulation of laser light in an FBG under the influence of sound pressure. The FBG hydrophone shows linearity, with dynamic range about 70 dB. It can measure amplitude and phase of an acoustic field in real time, and operates in a wide range of acoustic frequency, at least from 1 kHz to 3 MHz. No signal distortion is observed in the detected signal. Because of the simplicity in its operating principle and geometry, an FBG hydrophone is expected to be an acoustic sensor of high practicality compared to a conventional optical fiber hydrophone. 相似文献
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光纤Bragg光栅水听器特性及实验研究 总被引:4,自引:3,他引:1
论述了光纤Bragg光栅(FBG)水听器探头基元 (FBG)的传感特性,分析了FBG的耦合系数、反射率、反射带宽和栅长对光纤Bragg光栅水听器传感特性的影响.通过改进光纤Bragg光栅水听器探头封装结构,增加了其压力敏感系数.并将实验结果与标准水听器(压电型)比较,标定出光纤Bragg光栅水听器的声压灵敏度;对传感信号进行电路解调,得出了解调结果,结果显示与原始声波信号基本一致.试验表明,在1 kHz~25 kHz的声波检测范围,光纤Bragg光栅水听器响应平坦度好,信号输出稳定,证明文中采取的改进措施是有效的. 相似文献
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An exact linearity interrogation technique with enlarged dynamic range for fiber Bragg grating (FBG) sensor has been analyzed theoretically and demonstrated experimentally. The technique bases on two matched FBGs for receiving the reflected signal from the sensor FBG and two photodiodes (PDs) for collecting the reflected signal from the two receiver FBGs. The linear expression between the nature logarithm of the output ratio of the two PDs and Bragg wavelength of the sensor FBG is obtained on the condition that the bandwidths of the two receiver FBGs being equal to each other. The wavelength of the sensor FBG can be interrogated simply and accurately by the linearity technique according to the expression. In addition, a new tunable paralleled matched gratings interrogation scheme is proposed. The interrogation range can be enlarged and multiple FBG sensors can be interrogated simultaneously with the tunable interrogation scheme. 相似文献
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基于F-P腔和FBG的强度调制型光纤液位传感器 总被引:1,自引:0,他引:1
设计了一种用于液位测量的光纤F-P(Fabry-Perot)传感器,并从传感头的设计制作出发,讨论了提高传感器输出信号对比度的方法;测量系统采用宽带光源,解调时经FBG(Fiber Bragg Grating)反射和透射得到传感信号和参考信号,对两路光强信号进行联合处理,补偿了光源功率波动和光路损耗变化引起的不良影响,消除了强度调制型传感器的固有缺点,此方法具有结构简单、成本低的优点;该系统可进行连续测量,测量范围为0到200kPa,相当于测量水深0到20m,其分辨力小于1cm(水面高度变化),特别适合对易燃易爆的环境中的油库液位进行测量。 相似文献
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Underwater Acoustic Sensor with Fiber Bragg Grating 总被引:1,自引:0,他引:1
A new type of underwater acoustic sensor is proposed with an optical fiber Bragg grating (FBG). Because of the photoelasticity with respect to the refractive index and the elasticity of the fiber, the sound pressure in water modulates the Bragg reflection wavelength and, in turn, the intensity of the laser light transmitted through the FBG fiber. Good linearity between the detected signal and the sound pressure is obtained in the range from 81 dB to 140 dB re 1 μPa. Since the upper and lower limits of the acoustic signal level for operation of the sensor are limited by the driving circuit and the transduction of the sound in water, the sensor is expected to operate with much larger dynamic range both at higher and lower pressure levels. Operation of the sensor is very stable with the insertion of optical isolators into the system, although without the isolators the output signal fluctuates at low frequency due to the Fabry-Perot interference effect between the FBG and the various facets. 相似文献
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一种光纤光栅水听器灵敏度校准技术研究 总被引:1,自引:1,他引:0
为了校准光纤光栅水听器的灵敏度,开展了光纤光栅水听器灵敏度校准技术研究.本文首先介绍了光纤光栅水听器的工作原理;其次,采用可调谐激光器和带工作点控制的强度调制法,实现了光纤光栅水听器的信号解调和稳态测量;在此基础上,利用比较法建立了一种光纤光栅水听器校准系统,校准频率范围为20 Hz~10 kHz;最后,在该频率范围内对采用等效相移布喇格光栅研制的一只光纤光栅水听器的灵敏度进行了校准,对系统的测量不确定度进行了估算.结果表明,该系统可准确校准光纤光栅水听器的灵敏度,扩展不确定度为0.9 dB(k=2). 相似文献
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为了校准光纤光栅水听器的灵敏度,开展了光纤光栅水听器灵敏度校准技术研究.本文首先介绍了光纤光栅水听器的工作原理;其次,采用可调谐激光器和带工作点控制的强度调制法,实现了光纤光栅水听器的信号解调和稳态测量;在此基础上,利用比较法建立了一种光纤光栅水听器校准系统,校准频率范围为20 Hz~10 kHz;最后,在该频率范围内对采用等效相移布喇格光栅研制的一只光纤光栅水听器的灵敏度进行了校准,对系统的测量不确定度进行了估算.结果表明,该系统可准确校准光纤光栅水听器的灵敏度,扩展不确定度为0.9 dB(k=2). 相似文献