Linearly Configured Brillouin Optical Correlation Domain Analysis System Incorporating Time-Domain Data Processing

• Published in: Journal of lightwave technology Vol. 37; no. 18; pp. 4728 - 4733
• Main Authors: Ryu, Gukbeen, Kim, Gyu-Tae, Song, Kwang Yong, Lee, Sang Bae, Lee, Kwanil
• Format: Journal Article
• Language: English
• Published: New York IEEE 15-09-2019; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Correlation analysis; Data processing; Frequency modulation; Optical fiber sensors; Optical fibers; Probes; Scattering; Servers; Spatial resolution; stimulated Brillouin scattering; Time domain analysis
• ISSN: 0733-8724; 1558-2213
• DOI: 10.1109/JLT.2019.2919448

We propose a linearly configured Brillouin optical correlation domain analysis system incorporated with time domain data processing, where a fiber under test (FUT) is accessed from single end and multiple sensing points are simultaneously interrogated to extend the measurement range. In our scheme, correlation peaks (CPs) are sequentially generated by the interaction between a pump pulse outgoing from the system and a probe wave reflected from the end of an FUT, where the time-domain data processing is applied to obtain the Brillouin gain spectrum of each CP. In experiments, we demonstrate simultaneous acquisition of Brillouin gain spectra at 982 CPs with a spatial resolution of less than 5 cm and a sensing range extended from 10.3 m to 10.15 km. We also show that the amplitude of frequency modulation (Δ f ), which has been limited to the Brillouin frequency of an FUT in linear-configured BOCDA systems, can be enlarged without definite limitation by the time-domain data processing. In the experimental confirmation Δ f of 15.6 GHz, about 1.5 times of the Brillouin frequency of FUT, is successfully applied to simultaneous analysis of 98 CPs by the time-domain data processing.