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IMPROVED DATA PROSESSING ALGORITHMS IN BRILLOUIN REFLECTOMETERS FOR DETERMINING THE STRAIN OF OPTICAL FIBERS
Igor V. Bogachkov, Omsk State Technical University (OmSTU), Omsk, Russia,
bogachkov@mail.ru
Abstract
Tasks of monitoring and early diagnostics of optical fibers (OFs) OFs are important for companies operating fiber optical communication lines (FOCLs). Timely detection and elimination of fiber sections with bends, defects, increased mechanical strain and transformed temperature are required to avoid the gradual degradation and destruction of OFs in FOCLs. Specialized device – Brillouin optical time domain reflectometers (BOTDRs) – can be used for early diagnostics of OFs located in the laid optical cables (OCs). BOTDR are needed to detect fiber segments with increased longitudinal strain and transformed temperature. Usual optical time domain reflectometers are unfit for such tasks. A backscattered signal containing components of the Mandelstam – Brillouin scattering (MBS) is analyzed in BOTDRs. The process of determining the Mandelstam – Brillouin backscatter spectrum (MBBS) in the OF and then the longitudinal OF strain is very slow. Therefore, the task of improving the structure charts of devices for early diagnostics of FOCL and processing algorithms to accelerate a production of final results is important. The analysis of the BOTDR-reflectogram shows that not all counts taken in the points of the reflectogram with a sampling interval and a longitudinal coordinate are of interest for obtaining the final result. The result of this algorithm is an essential acceleration of the process due to gapping and ignoring the counts, which do not affect the final result. If at some step of the process the maximum is detected, then in parallel with the main process we can start the process of determining the OF strain and building a pattern of the strain distribution along the optical waveguide. In the next steps, the calculations will be adjusted. The pre-testing pattern of strain allows a skilled BOTDR user to interrupt the measurement process to make adjustments to the measurement settings (changing the scan range, the sampling interval and the resolution and distance of the measurement, etc.), which also reduce the testing time. Another way to accelerate the determination process is an adaptive change in the accumulation time of measurement results (the number of averages). When the data of MBBS characteristics is used from a database of different types of OFs and companies, the rate and efficiency of measurements can be improved. The work was carried out with the financial support of the Ministry of Education and Science of the Russian Federation within the scope of the base part of a State Assignment within the sphere of scientific activity (Project No. 8.9334.2017/8.9).
Keywords: optical fiber, strain, Mandelstam – Brillouin scattering, Brillouin reflectometer, Brillouin frequency shift.
References
- Bogachkov I. V., Gorlov N. I. (2013). Methods and means of monitoring and early diagnostics of fiber-optical transmission lines. Omsk: Publishing house OmSTU. 192 p.
- Bogachkov I. V. (2019). The detection of pre-crash sections of the optical fibers using the Brillouin reflectometry method. Dynamics of Systems, Mechanisms and Machines, Dynamics 2018: proceedings, Journal of Physics: Conference Series, рр. 1–11.
- Listvin A. V., Listvin V. N. (2005). Reflectometry of communication optical fibers. Moscow LESARart. 208 p.
- AQ 8603. Optical fiber strain analyzer. Instruction manual AS-62577. – Japan, Ando Electric Co Ltd., 2001. 190 p.
- Viavi MTS/T-BERD 8000 – fiber sensing module DTSS module: user manual. Viavi Solutions. 94 p.
- Bogachkov I. V. (2018). Patent of Russia on the useful model 186277, G 01 N 21/27. Brillouin optical time domain reflectometer for monitoring optical fibers, 2018135383/28(058291), publ. 10.2018.
- Bogachkov I. V. (2018). Patent of Russia on the useful model 186231, G 01 N 21/27. Optical Brillouin reflectometer, 2018135635/28(058643), publ.10.2018.
- Bogachkov I. V. (2018). Determination of mechanical stressed places of optical fibers in optical cables using Brillouin reflectometers. T-Comm,
12, no. 12, pp. 78-83. - Bogachkov I. V., Trukhina A. I., Gorlov N. I. (2019). Detection of optical fiber segments with mechanical stress in optical cables using Brillouin reflectometers. International Siberian Conference on Control and Communications (SIBCON–2019), Tomsk, pp. 1-6.
- Bogachkov I. V. (2017). Temperature Dependences of Mandelstam – Brillouin Backscatter Spectrum in Optical Fibers of Various Types. Systems of Signal Synchronization, Generating and Processing in Telecommunications (SINKHROINFO–2017), Kazan, pp. 1–
- Belal M., Newson T. P. (2012). Experimental examination of the variation of the spontaneous Brillouin power and frequency coefficients under the combined influence of temperature and strain. Journal of Lightwave Technology, vol. 30, no. 8, pp. 1250-1255.
- Bogachkov I. V., Trukhina A. I., Inivatov D. P., Kireev A. P., Gorlov N. I. (2019). A classification of optical fibers types on the spectrum profile of the Mandelstam – Brillouin backscattering. Dynamics of Systems, Mechanisms and Machines, Dynamics 2018 : proceedings, Journal of Physics: Conference Series, pp. 1-6.
- Bogachkov I. V., Inivatov D. P., Choban A. G. (2018). Certificate 23734 of electronic resource registration. Program for automatically detection the of optical fiber types on Brillouin traces (Russia, OmSTU), publ. 14.08.2018.
- Bogachkov I. V. (2019). Certificate 2019610752 of state registration of computer programs. Program for classification of optical fiber kinds on Brillouin reflectograms (Russia, OmSTU). 2018662391. 07.11.2018, publ. 18.01.2019.
Information about author:
Igor V. Bogachkov, Associate professor (docent) of «Communication means and information security» department of Omsk State Technical University (OmSTU), Omsk, Russia