Multilongitudinal mode fiber-ring laser sensor for strain measurement

作者:Liu, Shengchun*; Gu, Rong; Gao, Liang; Yin, Zuowei; Zhang, Liang; Chen, Xiangfei; Cheng, Jianchun
来源:Optical Engineering, 2011, 50(5): 054401.
DOI:10.1117/1.3574376

摘要

A multilongitudinal mode fiber ring laser sensor is proposed and experimentally demonstrated by measuring the strain applied on the laser sensor head. The ring cavity of the laser is formed by a 3-dB coupler, a section of erbium-doped fiber, and one fiber Bragg grating. Photonic generation of beat signals and strain measurement theory are discussed in detail. The strain applied on the fiber ring cavity is obtained by measuring the beat frequency shift. The selection way of the optimal beat signal for strain measurement is obtained by experimental research and discussion. The root-mean-square deviation of the strain and the response of beat frequency to the strain are 2.7 mu epsilon and 1.5 kHz/mu epsilon at 1993 MHz, respectively. The proposed sensor scheme offers a cost-effective and high-stability device for strain measurement.