High-resolution fiber Bragg grating sensor and its applications of geophysical exploration, seismic observation and marine engineering
Zhang Wentao1,2, Huang Wenzhu1,2, Li Fang1,2     
1. State Key Laboratory of Transducer Technology, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083, China;
2. College of Materials Science and Opto-Electronic Technology, University of Chinese Academy of Sciences, Beijing 100049, China

Overview: Nowadays, with the development of fiber Bragg grating (FBG) and FBG based resonant cavity engraving technique, signal demodulation technique, the measurement precision and frequency band range of FBG sensor are constantly improved. This can greatly promote its application in the field of geophysical exploration, seismic observation and marine observation. At present, high-precision broadband FBG sensor is still facing some challenges about core devices and key techniques. The core devices include high-fineness FBG based resonant, low-noise narrow-linewidth tunable laser. The key techniques include high-precision broadband FBG wavelength demodulation technique, large-scale networking technique and high-sensitivity signal pickup probe design. Firstly, this paper introduces the development of high-precision FBG sensing technique. Nearly three years, some novel sensing mechanism, demodulation method and sensing applications have been proposed. This improves the FBG low-frequency strain measurement resolution to 10-10, which makes it possible for the FBG sensors to be applied in geophysical exploration, seismic observation and marine observation. However, the system measurement resolution and dynamic range still need to be further improved. The high-precision temperature compensation and large-scale multiplexing technique are also the key problems to be solved. Secondly, this paper focuses on the cord devices and key techniques required for high-precision FBG sensing system and their applications in geophysical exploration, seismic observations and ocean observation. The cord devices include high-fineness FBG resonator, low noise narrow linewidth tunable laser. The key techniques include high-resolution broadband FBG signal interrogation technique, large-scale networking technique and high sensitivity signal detector design. Finally, in order to provide references for the development and application of high-precision fiber Bragg grating sensing technology, this paper aims to analyze and summarize some of the core techniques involved in high-precision FBG sensing technique and its application and the key issues that need to be solved in the field of geophysical exploration, seismic observation and marine observation.

Supported by National Key R & D Program of China (2017YFB0405503), NSFC (61605196), and Youth Innovation Promotion Association of CAS (2016106)