基于F-P腔的双边缘滤波解调系统研究

Research on Double-Edged Filter Demodulation System based on F-P Cavity

针对实现光纤布拉格光栅(FBG)传感器波长解调问题,提出将两个法布里-珀罗腔作为双边缘滤波器解调系统的方案。由于被反射的传感信号通过这两个光谱特征不同的滤波器时会产生不同程度的光强,所以可以利用两支路光强比值的对数算法来得到被测光的波长。最后通过计算和仿真验证了此系统能够较好地实现FBG信号的解调,仿真结果表明,系统的精度较高,线性度理想,而且系统在解调时不存在机械移动,因而测量速度更快,运行更稳定。

In this paper,we propose to use two Fabry-Perot(F-P)cavities as the double-edged filters to achieve the wavelength demodulation in Fiber Bragg Grating(FBG)sensor system.Since the reflected FBG signal through the two filters have different spectral characteristics and light intensities,the ratio of two intensities can be used to determine the wavelength of the measured light.Through the calculation and simulation,the system can realize the demodulation of the sensing FBG signal.The simulation results show that the system is more accurate with ideal linearity.Moreover,the system does not have mechanical movement at the time of demodulation,which means the measurement speed is faster and the running speed is more stable.