【作者】 汪波；

【导师】 王葵如；

【作者基本信息】 北京邮电大学 ， 物理电子学， 2013， 硕士

【摘要】 光纤光栅传感技术具有强抗干扰能力、高安全性、较多测量特征量、大测量动态范围、可分布式监测等特点,在传感领域有着广泛的应用。利用光纤光栅法布里-珀罗腔作为传感器,可以结合光纤光栅和法布里-珀罗腔的特点,实现高精度传感,并且具有解调方法灵活,便于复用的优点。利用傅里叶解调法,能够将波分复用与频分复用结合起来,在不同的波长范围内实现具有不同腔长的光纤光栅法布里-珀罗传感器的频分复用,可大大提高传感器的复用数量。并且,本解调方法只需利用计算机即可对多路信号进行同时解调,无需复杂的鳃调装置,可简化系统结构,提高稳定性。本论文分析了光栅F-P腔的透射谱在傅里叶频域的特性以及光栅F-P腔对温度和差分应变测量的机理,提出了一种利用光纤布拉格光栅法布里-珀罗腔传感器和傅里叶变换法实现温度和差分应变双参数同时检测的方法。制作了光纤布拉格光栅法布里-珀罗腔(FBG-FP)传感器,利用对绝对应变的测量代替对温度的测量,并进行了温度和差分应变的传感特性实验。实验结果表明,该传感器能够同时测量温度的绝对变化值和应变的相对变化值,对温度变化和差分应变的测量精度分别达到±191με和0.24℃,取得了较好的测量结果。为了提高光栅法布里珀罗腔传感器的测量范围,在对布拉格光栅法布里-珀罗腔的理论研究基础上,针对啁啾光栅具有大带宽的特点,本论文提出了利用两个啁啾光栅制作啁啾光纤光栅法布里-珀罗腔传感器进行双参数传感的方法。并通过数值仿真分析了其可行性,结果表明啁啾光栅法布里-珀罗腔(CFBG-FP)能实现较大范围内的温度和差分应力测量。此方法简单,稳定性好,具有较大的使用前景。更多还原

【Abstract】 Fiber grating sensor has the characteristic of anti-jamming capability, Fiber grating sensor has the advantages of anti-jamming capability, high security, more measurement characteristic quantities, large measurement dynamic range and so on. It can be widely applied in distributed sensing. The fiber grating Fabry-Perot cavity sensors, combining the characteristics of fiber gratings with Fabry-Perot cavity, have the advantages of high precision sensing, flexible demodulation method, easy to reuse. The application of Fourier transform demodulation,can bring about the frequency division multiplexing use fiber grating Fabry-Perot sesnors of different cavity length in different wavelength ranges, which can greatly increase the number of sensors multiplexed. Besides that, because this method completes the multiple signal demodulation by computer, we can simplify the structure and improve stability for demodulation system.In this dissertation, the mechanism of fiber grating F-P cavity on temperature and differential strain measurement has expounded and the transmission spectra of fiber grating F-P cavity in Fourier frequency domain is analyzed. The method to detect temperature and differential strain simultaneously by fiber Bragg grating Fabry-Perot cavity sensor and with Fourier transform demodulation is proposed., The fiber Bragg grating F-P cavity sensor is fabricated. The experiment on the measurement of absolute strain and differential strain is carried out.. Experimental results show that the sensor is able to measure the absolute change in temperature and the differential strain with the accuracy of0.24℃and±19με, respectively.In order to enlarge the measuring range, the method to detect dual parameter by chirped grating Fabry-Perot cavity.sensor is presented. Its feasibility is analyzed by numerical simulation. The results show that the method can achieve a wide range measurement of temperature and the differential strain.更多还原