【作者】 李卫；

【导师】 毕卫红；

【作者基本信息】 燕山大学 ， 电路与系统， 2004， 硕士

【摘要】 随着光纤光栅制造技术的不断完善，应用成果的不断出现，光纤光栅已成为目前最具有挑战性和最有发展前途的光纤无源器件之一。利用光纤光栅制作传感器一直是近些年来的研究热点。其研究关键在于提出一种经济有效的光纤光栅解调方案。文中分析了目前存在的各种光纤光栅的解调方案的优缺点，结合对光纤光栅反射原理的理论分析，在马赫-曾特(M-Z)干涉解调法的基础上提出一种相关取样的方法。此方法的主要出发点是消除M-Z干涉仪法对环境干扰的敏感性，使其能适用于静态测量，以解决目前M-Z干涉法无法实现静态测量的问题。论文首先在干涉仪的一个臂上引入压电陶瓷晶体(PZT)来调制干涉仪的相位，然后动态的监测干涉仪的正交工作点，每当监测到干涉仪处于正交工作状态时，转换干涉仪的状态，引入待测量光纤光栅反射的光信号进行解调。上述状态转换需要一定的时间，但当此转换时间足够小时可以认为这两个工作状态是高度相关的，用此特征可以有效地抵消掉了环境干扰的影响。为实现MZ干涉仪的相关取样，文中通过对可编程逻辑器件(CPLD)的编程实现了对上述状态转换所需的各种控制信号。并且详细设计了光电转换、前置放大、低通滤波、采样/保持等电路以及干涉光路。最后给出了实验结果，分析了试验系统的精度、测量范围、灵敏度等技术指标。验证了上述原理的正确性。更多还原

【Abstract】 With the improving technic and the emergence of more and more advance research production , fiber Bragg grating(FBG) had become one of the most successful optic passive device. Nowadays, As a worldwide research hotspot ,FBG sensor has been attracting many research teams. All their efforts is to develop a kind of FBG sensor simply and effectively. In this article, with the analyzing of advantage and disadvantage of all kinds of FBG demodulation scheme and the mechanism of FBG reflection, a new scheme named correlated sampling is advanced base on so called unbalanced M-Z interferometric demodulation technique. The main aim of this scheme is to eliminate the interferometer bias which is unavoidable in the M-Z interferometric demodulation technique and make it available in the field of static measure.To do so, a piezoelectric ceramics (PZT) be used to modulate the phase of the interferometer and when the interferometer is in quardrature condition the optic signal reflected by the FBG transmit into the interferometer for demodulating. The conversion of the states need some times, but if the time of conversion is short enough , we can believe that those two kinds of state is highly correlated, and the noise of the demodulation can be got rid of. To realize and test the method mentioned-above , the control circuit is designed by CPLD (Complicated Programmable Logic Device) and other unit circuit such as bias circuit of photodetector, preamplifier , sampling –holding circuit and low-pass filter are also designed in this article. In the end of this article the precision、the scope of measure、and the sensitivity of the experiment system are given.更多还原