Abstract

Fiber Bragg grating (FBG) based sensors have achieved great performance in dynamic strain sensing, while static strain measurement is still very challenging because it requires extra reference for temperature compensation. In this paper, a high-resolution FBG laser sensor system is presented, which is capable of both static and dynamic strain measurements. In the proposed sensor, a distributed feedback fiber laser (DFB-FL) works as the strain sensing element, and a distributed Bragg reflector fiber laser (DBR-FL) works as the reference. The DFB-FL is injection-locked to the DBR-FL with closed loop control using Pound–Drever–Hall (PDH) technique and an acousto-optic frequency shifter. No independent narrow-linewidth probe laser source is required. In experiments, a frequency fluctuation range of 31.6 kHz in 1000 s between the DFB-FL and the DBR-FL is obtained, corresponding to a static strain resolution of 248 pico-strain. Meanwhile, a dynamic resolution of 580 femto-strain at l kHz is achieved. The limitation on strain resolution and dynamic range of the sensor is also discussed. Due to the high strain resolution and moderate cost, the proposed sensor system provides a powerful tool for various applications of strain measurement.

© 2019 IEEE

DFB fiber laser static strain sensor based on beat frequency interrogation with a reference fiber laser locked to a FBG resonator

Wenzhu Huang, Shengwen Feng, Wentao Zhang, and Fang Li
Opt. Express 24(11) 12321-12329 (2016)

Fiber laser strain sensor based on an optical phase-locked loop

Wei Jin, Yibo Zhang, Yifan Qin, Yu Zhang, Cunkai Lou, Jiaxing Gao, Shanshan Li, Zhihai Liu, Fengjun Tian, and Libo Yuan
Opt. Lett. 48(20) 5245-5248 (2023)

Ultra-high-resolution large-dynamic-range optical fiber static strain sensor using Pound–Drever–Hall technique

Qingwen Liu, Tomochika Tokunaga, and Zuyuan He
Opt. Lett. 36(20) 4044-4046 (2011)

Ultrahigh resolution optical fiber strain sensor using dual Pound–Drever–Hall feedback loops

Jiageng Chen, Qingwen Liu, Xinyu Fan, and Zuyuan He
Opt. Lett. 41(5) 1066-1069 (2016)

Sub-nano resolution fiber-optic static strain sensor using a sideband interrogation technique

Qingwen Liu, Tomochika Tokunaga, and Zuyuan He
Opt. Lett. 37(3) 434-436 (2012)