光纤布拉格光栅(FBG)的波长随外界温度和压力变化。检测出波长的变化, 就可以计算出外界的温度和压力。文章提出了一个基于F-P温控标准具的高稳定性光纤布拉格光栅(FBG)波长解调系统, 讨论分析了FBG波长解调系统的原理及高稳定性的原因。在这个系统中, 带温控模块的F-P标准具用来进行实时波长校准。F-P标准具的波长数值可查询得到, 由线性插值算法可以得出光纤光栅的波长值。温控模块可以保证标准具在±0.01 ℃的范围内变化, 因此标准具波长值可以认为是定值。最后通过测量水浴槽中光纤光栅的波长变化测试系统稳定性,并与MOI公司解调仪sm125在稳定性方面做了对比。实验结果表明20 h内系统的长期稳定性可达到±0.15 pm,而sm125解调仪是±3 pm。

Wavelength of Fiber Bragg Grating(FBG) changes with ambient temperature and pressure. If change of wavelength is detected, then ambient temperature and pressure can be calculated. In this paper, a highly stable Fiber Bragg Grating(FBG) wavelength demodulation system based on F-P etalon with tempe-rature control module was proposed. The theory of the FBG wavelength demodulation system was discussed and the reason of high stability was analyzed. In this system, a Fabry Perot(F-P) etalon with temperature control module was introduced for real-time wavelength calibration. Wavelengths of F-P etalon can be inquired by the specification. Wavelength of FBG can be calculated by linear interpolation. The temperature control module can ensure temperature of the etalon changes within ±0.01 ℃, so that wavelengths of the etalon can be regarded as constant values. In the end the stability of the system was experimented by measuring wavelengths of FBG which was in a water-bath. The system was also compared with the MOI corporation optical sensing interrogator sm125 on the stability. Experimental results demonstrate that the system can achieve a long-term stability of ±0.15 pm in 20 h, while sm125 was ±3 pm.