Large-scale strain sensor based on distance reposition method by permanent scatters in OFDR system

• DOI: 10.1364/opticaopen.29022248.v1
• Publication Date: 2025-05-12T06:13:38Z
• Authors: Yong Kang Dong; Xinyue Yu; Shuaiqi Liu; Xing Liu; Jinglin Sui; Yuchen Zhou; Hongwei Li; Yuelan Lu; Dexin Ba
• Keywords: Strain (injury)

Large-scale strain (i.e., large in wide-range optical fiber) distorts distance referencing spectrum-based frequency-domain reflectometry (OFDR), resulting severe position segment mismatches and degraded accuracy. In this letter, a reposition method (DRM) is proposed, which employs femtosecond-laser-inscribed permanent scatter (PS) array as in-fiber reference markers. By realigning adjacent fiber segments to repositioned PS positions, the DRM enables sufficient self-correction against strain-induced spatial for sections during each local demodulation process, thereby enhancing correlation accuracy of RBS spectra obtained by measurement signals. The PSs are inscribed with an interval 12 cm 2.29 m-long region, enhancement approximately 25 dB negligible insertion loss. Experimental results demonstrate that significantly improves performance large-scale sensing, enabling distributed sensing up 5000 µε over 1 m 6.4 mm resolution. This technique provides simple practical approach OFDR systems.