Abstract

Electrical current monitoring plays an important role in power transmission system, electric instruments, etc. The stability of the monitoring system is highly demanded. In this paper, a new interrogation scheme for a fiber Bragg grating (FBG) current sensor based on a dual-loop optoelectronic oscillator (OEO) with high stability, high precision and simple structure is proposed and experimentally demonstrated. The wavelength shift of the FBG, which is bonded on a magnetostrictive alloy-strip, is converted into the frequency shift of the microwave signal through the OEO system utilizing the wavelength to frequency mapping mechanism. Different from previous single-loop OEO schemes, a length of ∼1 km single mode fiber is used to form the second loop in the OEO-cavity, which can enhance the mode-selection ability and reduce the total gain requirement of the system. In addition, a fiber-ring-laser (FRL) cavity is adopted by integrating the sensing FBG-head as the wavelength-selective component to improve the quality of the optical carrier signal. The measured side-mode suppression ratio (SMSR) is up to 62.59 dB and the free spectral range (FSR) is five times larger than the single-loop structure, resulting in highly-enhanced stability and so the precision. Most importantly, the frequency fluctuation is as low as 0.277 ppm, which is the minimum to the best of our knowledge. Compensating methods for the influence of the temperature and the hysteresis are also discussed. The proposed scheme provides a feasible solution to promoting the development of OEO-based interrogation technology and its commercial applications.

High sensitivity demodulation of a reflective interferometer-based optical current sensor using an optoelectronic oscillator

Muguang Wang, Naihan Zhang, Xiaodi Huang, Bin Yin, Hongqian Mu, Mengyao Han, and Desheng Chen
Opt. Lett. 45(16) 4519-4522 (2020)

High-sensitivity optical fiber temperature sensor based on a dual-loop optoelectronic oscillator with the Vernier effect

Yunjie Cheng, Yiping Wang, Zixuan Song, and Jing Lei
Opt. Express 28(23) 35264-35271 (2020)

Fiber Bragg grating sensor interrogation system based on an optoelectronic oscillator loop

Zuowei Xu, Xuewen Shu, and Hongyan Fu
Opt. Express 27(16) 23274-23281 (2019)

High-precision temperature-compensated fiber Bragg grating axial strain sensing system based on a dual-loop optoelectronic oscillator with the enhanced Vernier effect

Lingge Gao, Yiping Wang, Xiaozhong Tian, Yunhao Xiao, Qiang Liu, and Dan Zhu
Appl. Opt. 62(19) 5317-5324 (2023)

High-precision thermal-insensitive strain sensor based on optoelectronic oscillator

ZhiQiang Fan, Jun Su, Tianhang Zhang, Ning Yang, and Qi Qiu
Opt. Express 25(22) 27037-27050 (2017)