【作者】 张文；

【导师】 陈伟民；

【作者基本信息】 重庆大学 ， 光学工程， 2004， 硕士

【摘要】 光纤传感器具有易于复用、不受电磁干扰、绝缘性能高、 防爆性能好、耐腐蚀等优点,随着光纤通讯技术的发展而得到日益广泛的应用。其中,光纤F-P传感器和光纤FBG传感器是光纤传感器的典型代表,两者各有所长,均得到了广泛的应用。随着光纤传感技术的发展,提出了在大型工程中同时采用这两种传感器的要求。在这种情况下,如果采用两套独立的解调装置分别对光纤F-P传感器、光纤FBG传感器的传感信号进行解调,虽然在技术上比较成熟,但同时也增加了解调系统的复杂程度,降低了系统的可靠性,明显提高了解调成本,阻碍了光纤传感器更为广泛的应用。因此,对光纤F-P/FBG光栅通用解调技术进行研究具有必要性。 本文首先对国内外光纤F-P传感器、光纤FBG传感器的解调技术现状进行较深入的分析,总结出引入可调F-P滤波器可以对光纤F-P传感器、光纤FBG传感器信号分别进行解调,有望以此为基础实现光纤F-P/FBG光栅通用解调。因此,进一步分析了滤波型可调F-P解调装置的传输损耗特性,光源光谱实际分布对于光纤F-P传感器输出信号的影响,深入讨论了基于可调F-P滤波器的光纤F-P传感解调原理;另一方面,介绍了FBG的成栅工艺和传感特性,分析了FBG温度应力/交叉敏感性的利用与补偿原理,并对使用可调F-P滤波器的光纤FBG解调过程中的波形延拓现象和可调F-P滤波器非线性对FBG解调的影响进行了讨论。在此基础上,讨论了两种解调系统对光源带宽要求、可调F-P滤波器指标和光路效率等方面的不同要求,论证了引入可调F-P滤波器实现光纤F-P/FBG光栅通用解调在原理上和技术上的可行性;考虑到可调F-P滤波器表现的非线性,分析了引入基准光路补偿非线性解调误差的原理,提出了采用FBG作为波长基准的方法,进而完成了FBG波长基准器件的研制和光纤F-P/FBG光栅通用解调系统光路设计。以光路确定为前提,进行了SLD光源驱动电路、FBG波长基准控制电路和可调F-P滤波器控制电路的论证和设计工作。最后,通过实验验证了FBG波长基准器件、SLD光源驱动电路、可调F-P滤波器控制电路等自行研制的各个部件的各项性能,并在此基础上进行光纤F-P/FBG光栅通用解调系统进行了F-P解调和FBG解调的实验。实验结果说明,整套光纤F-P/FBG光栅通用解调系统能够正常工作,实现了预期的功能。更多还原

【Abstract】 With the development of optic fiber communication technology, optic fiber sensors are widely used. With monitoring the changing of optic intensity, wavelength, phase and polarization state, optic fiber sensors can detect many parameters, such as pressure, strain, temperature, etc. They have the advantages of simple structure, easily duplicated, low sensitivity towards magnetic, high insulation and good defending bursting capability. There are two typical optic fiber sensors, fiber F-P (Fabry-Perot) sensor and fiber FBG (Fiber Bragg Grating) sensor. Each has many advantages, and has been already widely used. These two sensors are synchronously demanded in great engineering. Otherwise, existing demodulating method increases the complexity of demodulating system, decreasing dependability and enhancing cost of system. So it is necessary to study general demodulating method for F-P/FBG sensor. So some researches are carried on in this paper.At the beginning of this paper, the principle of many kinds of demodulation methods for fiber F-P/FBG sensors are analyzed and compared. A conclusion is drawn that using tunable F-P filter can realize demodulation for fiber F-P sensors and fiber FBG sensors separately. In order to validate the availability of general demodulation system for fiber F-P/FBG sensors using a tunable F-P filter, wastage characteristic of tunable F-P modulating device and the effect of actual spectrum to sensor output are deeply analyzed, modulating principle based tunable F-P filter is thorough discussed. And considering non-linearity of tunable F-P filter, benchmark compensation for non-linearity demodulating principle is put forward, which using a series of FBG wavelength references as benchmarks. The device of FBG wavelength reference is studied and manufactured, and general demodulation system is designed. SLD light source driving circuit, controlling circuit of FBG wavelength reference and tunable F-P filter are analyzed and designed. Finally, experiments of F-P and FBG demodulating system are carried. Experiments indicate that the performance of these circuits and parts are usable and dependable and such demodulating system is in good working.更多还原