Li Chengli, Tang Jianguan, Cheng Cheng, Cai Longbao, Guo Huiyong, Yang Minghong
Opt Express. 2020 Nov 9;28(23):34309-34319. doi: 10.1364/OE.405536.
A fiber-optic sensing system based on two types of ultra-weak fiber Bragg gratings (UWFBG) for simultaneous temperature and vibration sensing was proposed. Narrowband and broadband UWFBGs are alternately written into an optical fiber with equal spacing. Distributed temperature sensing is realized by demodulating the wavelength shift of the narrowband UWFBG, while distributed vibration sensing is achieved by detecting phase variation between two adjacent broadband UWFBG interference pulses. The experimental results show that the proposed hybrid UWFBG array can perform temperature and vibration sensing simultaneously. The experimentally conducted temperature measurement ranges from 20°C to 100°C, with the measurement error less than 0.1°C. Vibration signals at different temperatures can be accurately restored, and the signal-to-noise ratio (SNR) is improved by 21.1 dB compared with a normal single-mode fiber (SMF).
提出了一种基于两种类型超弱光纤布拉格光栅（UWFBG）的光纤传感系统，用于同时进行温度和振动传感。窄带和宽带UWFBG以相等间距交替写入光纤中。通过解调窄带UWFBG的波长偏移实现分布式温度传感，而通过检测两个相邻宽带UWFBG干涉脉冲之间的相位变化实现分布式振动传感。实验结果表明，所提出的混合UWFBG阵列能够同时进行温度和振动传感。实验进行的温度测量范围为20°C至100°C，测量误差小于0.1°C。不同温度下的振动信号能够被准确恢复，与普通单模光纤（SMF）相比，信噪比（SNR）提高了21.1 dB。
