基于马赫-曾德尔干涉仪的光纤光栅脉搏波解调方法

Demodulation Method of Pulse-Wave Sensing by Fiber Bragg Grating Based on Mach-Zehnder Interferometer

提出了一种用于智能服装中脉搏检测的光纤布拉格光栅(FBG)波长解调方法。基于光子晶体光纤(PCF)制作了一种基于模间干涉的在线马赫-曾德尔干涉仪(In-line MZI),将其作为边沿滤波器应用到FBG波长解调系统中,其温度灵敏度不超过3.5 pm/℃(25℃~60℃范围内)。实验结果表明,本解调系统能够实现2 nm范围内的线性解调,波长灵敏度为0.055 nm^(-1),波长分辨率可达2.2 pm,对FBG脉搏信号的解调结果与SM130波长解调仪的解调结果相一致。

A wavelength demodulated method of fiber Bragg grating （FBG） is proposed to measuring pulse signal, which can be applied to smart clothing. Based on the photonic crystal fiber （PCF）, a kind of Mach-Zehnder interferometer （In-line MZI） is fabricated on the basis of mode interference. The interferometer works as an edge filter in the wavelength demodulation system of FBG. The temperature sensitivity of the interferometer is lower than 3.5 pm/℃ （range from 25 ℃ to 60℃）. The experiment results indicate that the system can achieve linear demodulation within the range of 2 nm, with a wavelength sensitivity of 0.055 nm 1 and a wavelength resolution of 2.2 pm. The demodulation results of FBG pulse signal measured from the proposed system are consistent with the results measured from SM 130 demodulation instrument.