Chaos Raman distributed optical fiber sensing

• Published in: Light, science & applications Vol. 12; no. 1; p. 213
• Main Authors: Wang, Chenyi, Li, Jian, Zhou, Xinxin, Cheng, Zijia, Qiao, Lijun, Xue, Xiaohui, Zhang, Mingjiang
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 31.08.2023; Springer Nature B.V; Nature Publishing Group
• Subjects: 639/624/1107/510; 639/624/400; Flight; Lasers; Light; Microwaves; Optical and Electronic Materials; Optical Devices; Optics; Photonics; Physics; Physics and Astronomy; RF and Optical Engineering; Spatial discrimination
• ISSN: 2047-7538; 2095-5545; 2047-7538
• DOI: 10.1038/s41377-023-01267-3

The physics principle of pulse flight positioning is the main theoretical bottleneck that restricts the spatial resolution of the existing Raman distributed optical fiber sensing scheme. Owing to the pulse width of tens of nanoseconds, the spatial resolution of the existing Raman distributed optical fiber sensing scheme with kilometer-level sensing distance is limited to the meter level, which seriously restricts the development of the optical time-domain reflection system. In this paper, a chaos laser is proposed in the context of the physical principle of the Raman scattering effect, and a novel theory of chaos Raman distributed optical fiber sensing scheme is presented. The scheme reveals the characteristics of chaos Raman scattering light excited by a chaotic signal on the sensing fiber. Further, the chaos time-domain compression demodulation mechanism between the temperature variation information and chaos correlation peak is demonstrated. Then, the position of the temperature variation signal is precisely located using the delay time of the chaos correlation peak combined with the chaos pulse flight time. Based on this novel optical sensing mechanism, an experiment with 10 cm spatial resolution and 1.4 km sensing distance was conducted, and the spatial resolution was found to be independent of the sensing distance. Within the limit of the existing spatial resolution theory, the spatial resolution of the proposed scheme is 50 times higher than that of the traditional scheme. The scheme also provides a new research direction for optical chaos and optical fiber sensing. The first combination of chaos laser and Raman distributed optical fiber sensing breaks the physical bottleneck of spatial resolution, the optimal spatial resolution of the current kilometer-level sensing distance is achieved.