[19a-H116-1~12] 3.16 Optics and Photonics English Session

▼ [19a-H116-12] BOCDR assisted by the slope of Brillouin scattering spectrum

〇(M1)Heeyoung Lee¹, Neisei Hayashi¹, Yosuke Mizuno¹, Kentaro Nakamura¹ (1.Tokyo Tech)

Keywords:Brillouin scattering,Optical fiber sensors,Strain and temperature sensing

To monitor the conditions of civil infrastructures, a variety of fiber-optic distributed strain and temperature sensing techniques based on Brillouin scattering have been extensively studied. Among them, Brillouin optical correlation-domain reflectometry (BOCDR) has attracted significant attention due to its unique advantages such as a high spatial resolution, one-end accessibility, and cost efficiency. Conventional BOCDR, which provides the information on Brillouin frequency shift (BFS) distribution, operates properly even when optical loss occurs in the fiber under test (FUT). This feature is an advantage from the aspect of stable strain and temperature measurement; however, in some practical applications, optical loss distribution should be simultaneously obtained. In this study, to achieve simultaneous distributed measurement of strain/temperature and loss, we develop a new BOCDR configuration –– slope-assisted BOCDR (SA-BOCDR) –– which operates with the assistance of the Brillouin gain spectrum (BGS) slope. In this method, the whole BGS spectrum does not need to be observed to derive the BFS value, which leads to a higher sampling (or repetition) rate. As a result, the distributed information on the strain, temperature change, and loss was correctly obtained and thus the basic operation of SA-BOCDR was verified.