High-performance optical chirp chain BOTDA by using a pattern recognition algorithm and the differential pulse-width pair technique

• DOI: 10.1364/prj.7.000652
• Publication Date: 2019-05-21T21:29:30Z
• Authors: Benzhang Wang; Baohua Fan; Dengwang Zhou; Chao Pang; Yue Li; Dexin Ba; Yongkang Dong
• Keywords: Brillouin zone; Modulation (music); Chirp; Center frequency

Optical chirp chain Brillouin optical time-domain analysis (OCC-BOTDA) has the capabilities of fast measurement, high threshold, and freedom from nonlocal effect; at same time, however, it also problems introduced by transient stimulated scattering. The influence interaction is reflected as broadened asymmetric spectrum, ghost peak, frequency shift main peak. This introduces difficulty in computing fiber with good measurement accuracy. Besides, OCC modulation causes additional noise due to uneven amplitude response for different components. In this work, we propose a high-performance OCC-BOTDA using principal component (PCA) based pattern recognition algorithm differential pulse-width pair (DPP) technique. After building spectrum database (i.e., all patterns), intrinsic can be recognized PCA nonstandard profile, resulting Meanwhile, DPP technique, subtracting between two signals generated wide-width pump pulses, utilized reduce avoid pulse self-phase effect long-range BOTDA sensing. experiment, temperature 1.3 MHz precision, 4 m spatial resolution, 5 s time achieved over 100 km single-mode fiber.