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IMPROVED DATA PROCESSING ALGORITHMS IN BRILLOUIN REFLECTOMETERS FOR DETERMINING THE STRAIN OF OPTICAL FIBERS
DOI 10.24411/2072-8735-2018-10292
Igor V. Bogachkov,
Omsk State Technical University (OmSTU), Omsk, Russia, bogachkov@mail.ru
Keywords: optical fiber, strain, Mandelstam -Brillouin scattering, Brillouin reflectometer, Brillouin frequency shift.
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).
Information about author:
Igor V. Bogachkov, Associate professor (docent) of "Communication means and information security" department of Omsk State Technical University (OmSTU), Omsk, Russia
Для цитирования:
Богачков И.В. Улучшение алгоритмов обработки данных в Бриллюэновских рефлектометрах при определении натяжения оптических волокон // T-Comm: Телекоммуникации и транспорт. 2019. Том 13. №7. С. 60-64.
For citation:
Bogachkov I.V. (2019). Improved data processing algorithms in Brillouin reflectometers for determining the strain of optical fibers. T-Comm, vol. 13, no.7, pр. 60-64.
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Fiber optical communication lines (FOCL) are widely used in modem infocommuni cation systems. Tasks of monitoring and early diagnostics of optica! Fibers (OF) arc important lor companies operating FOCL [1, 2],
Timely detection and elimination oF potentially hazardous segments in an OF (segments with bends, cracks (defects), increased mechanical strain and transformed temperature, with different types of unauthorized access to the OF) are required to avoid the gradual degradation and destruction of the OF in FOCL [2,3].
Specialized device - Brillouin optical time domain re Hectometer (HOT DR.) can be used for early diagnostics ofOFs located in the laid optical cables (OCs) [2 - 7]. This BOTDR is needed to detect OF segments with increased longitudinal strain and transformed temperature. Usual optical time domain re Hectometers (OTDRs) arc unfit For sueh tasks, because backseat-tered Rayleigh scattering signal is analyzed in them, a frequency Of which is equal to a frequency of a probe radiation, hi contrast, in the BOTDR a backseattered signal containing components of the Mandelslam - Brillouin scattering (MBS) is analyzed [2 - 4].
Receiving a distribution pattern of a Mandelstam - Brillouin backseat ter spectrum (MBBS) along an OF (3D-BOTDR reflectogram of MBBS distribution) we Find a Brillouin frequency shift (Jn). After that, a distribution pattern of the strain is constructed along the OF [2,31,
The attractive feature of the BOTDR (compared with other devices for determining the strain in an OF) is one-end access to the OF. The process of determining the/5, ¡11 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.
In the traditional structure chart of the BOTDR either a Frequency of radiation introduced into the OF (a frequency of the emitting laser in transmission path) changes, which is necessary to simplify a receive path, since it will be configured to receive the backscattered signal with fixed frequency [3]. Or tuning of the receive path in frequency of the backscattered signal is carried out, which allows as to do without tuning a frequency of an emitting laser in the transmission path [4|.
Fig. I shows the structure chart for the last case |4|.
J1
A EX'f'A
t > EM
A ±f*
Ci' muiej tesî
mi
PD ---> F'miucituy onjveiroj
> SîluIIII
Fig. I. Simplified structure chart of BOTDR
The emitting source is a laser diode ( L ) {_!) is the frequency of emitting laser in the transmission path); the pulse modulation is made by an electro-absorption modulator (EM). After that, the optical signal is amplified in the erbium-doped liber amplifier (EDFA) and then il is supplied to the OF under test through a directional coupler (DC) or a circulator.
The backscattered optical signa! is guided to the photodelector (PD) through a DC or circulator. This signal consists of both a
component of Rayleigh scattering (a frequency is equal to a radiation frequency in the transmission path (ft)) and two components of MBS (Stokes and anti-Stokes). The Stokes component is shifted downwards in frequency (// - fa), and the anti-Stokes component is shifted upwards (/J Coherent radiation reception is used to isolate the Stokes component (more powerful). A smaller part of the laser radiation power is supplied to the PD input, where it is mixed with the radiation scattered 111 the OF.
Coherent reception is used to increase the sensitivity of the PD. In comparison with the direct detection chart applied in traditional OTDR the improvement is about l() - 20 dB |3,4].
A11 addition, it is necessary to apply more sensitive PD in BOTDR (in comparison with OTDR) because a coefficient of spontaneous MBS about 14 dB is less than a coefficient of Rayleigh scattering [ 1,4]. A 3 D-distribution of spectrum of the spontaneous MBS along the optical waveguide is found for each frequency and then a "peak" frequency of the MBBS is determined. Alter determining the //j, the strain distribution along the OF is calculated. A peak signal level in I'D (MBBS maximum) is fD.
The MBBS profile along the optical waveguide is determined by separating the difference between the j) frequency and the Spectrum frequencies of the backscattered signal in the receiv e path. The difference frequencies (corresponding to MBBS) occupy a band from 9,5 C1H7 to 11.4 GHz at a wavelength of 1.55 Hiii (At) of the emitting laser. After that, in the frequency converter usually performed as a heterodyne scheme the frequency of the scan range under study is reduced 10 the threshold that allows digital signal processing in the signal processor to be performed. A slightly different scheme was implemented in the BOTDR |3].
The frequency shift (A f) is carried out by an aco us to-optic a I modulator (AOM); the pulse modulation is made by an EM. After polarization change in the Faraday phase shifter the optical signal is amplified in EDFA and then it is supplied to the OF under test through a DC or a circulator.
The backscattered optical signal is guided to the PD through a DC or circulator. This signal consists of both a component of Rayleigh scattering la frequency is equal to fL +Af) and two components of MBS (Stokes and anti-Stokes). The Stokes component is shifted downwards in frequency (j) + A/- fa), and the anti-Stokes component is shifted upwards (j] +A/'+fg).
Coherent radiation reception is used to isolate the Stokes component. A smaller part of the laser radiation power is supplied to the f'D input, where it is mixed with the radiation scattered in the OF.
A 3 D-distribution of Spectrum of the spontaneous MBS along the optical waveguide is found for each frequency fL + A/, and then a "peak" frequency of the MBBS is determined. After determining the fa, the strain distribution along the OF is calculated, A peak signal level in I'D (MBBS maximum) is achieved when the AOM frequency shift (A/) is,/a.
Also, there are other types of structure charts of BOTDR (5 - 7|.
For instance, it is possible to use Rayleigh reflectogram for analysis as well as in OTDR [5], and also the introduction of a reference channel containing either an OF in the reference receive channel [(1] or a reference reflectogram from the database of different OF types [7, !2- 14").
As is known, the frequency profile of MBBS (g£f) -Brillouin gain coefficient, (BGC)) has a "Lorenizian profile" (parabolic shape) in the region of the main maximum ("peak"):
./; -f-fu
ut
where is the maximum DGC at the / = j) - JB\ Afn is the bandwidth of the MBBS (Brillouin gain) [2- 4ft
fe(E£.T)=2 ftvt (E,.T) ,V / n = 2v, {Eej) ntf IA, . (2)
where EL is the Ynung's module (strain), T - temperature, T) is the velocity of a hyperacoustic wave depending on the temperature, strain and core structure; nt.r is the effective re-fraetive index of the medium, c is the velocity of light in vacuum [8 - 11 j. Sensing the OF by short pulses the MBBS distribution along the optical waveguide is found. After the analysis of the distribution pattern of the MBBS in OF the fg is determined (the values of MBBS peaks) along the OF ifa{Ec))-
It is enables us to determine the strain degree of the OF and detect the location of the distributed irregularities in the OF by applying the MBBS /¿(£,) dependence:
[>t * to».;«: j 0.91974 ki* | F"L: TO. SIOOHx I mqumaytlîô.eennit | F2; lT.uioan* | o*, wag
Ik* JOIl ■ f I 4 (Ï 010] C , W, 1 10»» hvc, 2"-1.7 Rd« . : O. 10m F'roigitonry Stnrti tOiiOGHz Sampler SX/GO Stop ; U.HWiilz Swoop r 1 DMlti
¡nil. o* . 701U HJiOft:15
E (2)= -»■ -. A£ (z)= ■ . (3)
Mty'Cf fMCj
where Et{i) is the dependence of OF strain on the longitudinal z coordinate along the OF; AEjz) is the change in OF strain from the initial value; _/(£■„ :) is the dependence of the frequency shift from the strain and z coordinate; fn (0) is the initial value of Jr\ 4fn(z) is the change oi'fu from the z coordinate along the OF, for
G. 652 C'cf is 48 kl \7J\iZ = 480 MHz/% (1% of strain is equal to
1114 (is) or is taken to be 493 MHz/% at room temperature according to the "Fujikura" [3,4],
It is known that three points are necessary for unambiguous definition of the parabolic curve. To accurately determine the //, not just a frequency of received signal with a maximum of gc is selected, but approximation in adjacent counts in the "peak" region is performed to estimate the MBBS maximum. Thus the square parabola passing through these counts is shaped. In the simplest ease, the bandwidth at half power (-3 dB) of the maximum value is calculated for this parabola, and then the fB is estimated as an average frequency of this range [4|.
Fig, 2 shows a 3D-re Hectogram BOTDR, which presents a distribution pattern of MBBS along the optical waveguide. The cross section of Stich 3D-re Hectogram BOTDR along the longitudinal coordinate is a rellectogram of OF at a fixed frequency. Along the frequency axis, each value of the longitudinal coordinate (; = const) determines the MBBS profile in this cross section [8- 10].
The lower right corner of the rellectogram shows both the MBBS maximum for a specific longitudinal coordinate and the response of MBBS profile in this cross section of the OF. For example, when the cross liber section of; = 919.7 m the MBBS peak is observed at a frequency of 10.89 GFIz with width of MBBS of 185.4 MHz and the signal level of 84.9 dB.
A core refractive index of the OF is n = 1.4681. The measurement accuracy in the longitudinal coordinate is 0,1 m. The real spatial resolution is 1 in for the probe pulse width of 10 ns.
The start frequency of the measurement range (Fl) is 10.55 GHz, the slop (F2) is 11.14 GHz with a sweep frequency of 10 MHz. The number of averages is equal to 2' ,
Fig. 2. A 3D-re Hectogram BOTDR - distribution patterns of MBBS along the optical waveguide
Experience with the "Ando AQ 8603" has shown that the measurement process is very slow at high resolution.
In order to start the measurement we need to set the scan range with start (Fl) and stop frequency (F2), as well as the sampling interval (A/), which is equable and depends on both the specitied number of measurement points (N) and the number of averages. This value is called "average time" in usual OTDR.
For example, the process of obtaining the rellectograms can take about one hour with 50 measurement points, the spatial accuracy of the rellectogram of 0.05 m and the number of averages of 21 . Despite the fact that this time can be significantly reduced by applying smaller values, it remains significant in comparison with usual OTDR.
Typical values for the initial level (for normal conditions: at room temperature without mechanical strains) of the Brillouin frequency shift {fun) are obtained for the frequently used types of OF [12 - 14]. For standard single-mode OF (ITU-T recommendation G, 652) the fB„ is within W. 83... 10.86 GHz. For frequently used types of OF the fst, values can be used from the database 112 - 14] to determine the frequency scan range of the measured MBS signal.
The process of determining the MBBS maximum can be significantly accelerated by adapting the measurement one.
The analysis of the BOTDR-rellectogram shows that not all counts taken in the points of the rellectogram with a sampling interval (A/) and a longitudinal coordinate (A/.) are of interest for obtaining the final result as presented in Fig. 3.
Fig. 3 shows the explanation of the discussed algorithm of processing the BOTDR-reHectogram. N corresponds to the number of the current sample, ¿i > zi > z$ > > > are the values in fixed {selected) cross sections (longitudinal coordinates (z = const)).
At the initial step, the measurement range is divided into 4 identical parts with an interval of A/): in addition to the start (Fl) and stop (F2) frequencies, three more counts spaced from each other by the interval value are determined.
A/!^(F2-F1)}Aj J) = F1, fg = fj 4-Afj ,
f^fj+Uf,, ./W/+-W,. h = ^• (4)
After thai, in each cross section the intensity of the backscat-tered signal /(/. -) is determined and the peak value for the current counts (counts I - 5) is selected by a specified scanning interval along lite longitudinal coordinate of zh
Then the sampling interval is reduced twice Af,~Af,i2-
but the following construction of relleclograms on the frequencies of the baekseattered signal is carried out only in segments with signal levels having power comparable to the peak level (less than 5 dB from the "peak") for each cross section along the longitudinalz coordinate (counts 6 - 7).
The counts in the maximum region are necessary for further analysis (detenuination of fu), and the counts with power less than 5 dii relative to the peak level are excluded from further process. The "usable" counts are indicated by "points" in the MBRS profile, and the "unusable" counts for the definition Ol'fs are pointed by "crosses" as shown in Fig. 3.
In the same way the intensity of the baekseattered signal /(/, -) is determined for the obtained counts (6, 7}, and the peak value is selected for all counts (1-7) achieved at this step for die
Ltrrer /tr.ll. ft t value • • « l t 1 ■ • 1 l ----, - .....„.I--"*' oft - he IB lo » " — ngitUí |7| l> 14 19 JO J tI: Jil a ia! y 1 n ■ CO 1 M J ordinate of- | ' JO ^ ii 7<M ■ i ■ i i i i i i ■ i---- i ft
i f t • 1 f V ......( r-' - - i i i i
n l l l 1 t ......A...... 4 - i i i i i .......
T i i • bid .... i-" ■ •j —... .......■-*—i 1 1 1 1 - - - l -■ Â*
À/ i i • i 1 i * i II t ■ i 1 : M ■ 1 1 I ff
r, r,
m torn)
Fig. 3. Selection of counts in the BUT DR-re Hectogram with adaptive algorithm
Then die process is repeated periodically at the new maximum region with a halved interval Af = Aj] , /2 ■ It continues until
the minimum interval is reached. The fB value is then adjusted using the algorithms described above. In Fig. 3 the third step corresponds to the counts of 8 - 10. the fourth step is attributable to the counts of 11-16 and the fifth - to the counts of 17 - 25,
If the positions of the peaks are in various counts (for example, in sections ofr/(/V = 7) and z3 (N - 3) in Fig. 3) for different values of the longitudinal r coordinate, then in each cross section of;, only counts with power not lower than 5 dB from the maximum level are analyzed (indicated by "points" in Fig. 3), and other counts pointed by "crosses" in Fig. 3 are neglected.
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 based on the equation (3) and building a pattern of its distribution along the optical waveguide ££z). In the next steps, Ihe calculations will be adjusted. The pre-testing pattern of E^z) allows a skilled BOTDli 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 lime of measurement results (the number of averages). Firstly, (the first step of measurements, counts 1 5) a small number of averages is taken (for example, 21"), in the next steps it increases (for example, 21' -2|J, counts 6 - 10), and only in the maximum region the number of averages becomes the maximum for the specified conditions < for example, 217, counts 17-25).
The algorithms presented in this paper allow lis to accelerate the process of obtaining the final results in the BOTDR due to the expulsion of unusable counts from the processing operations.
When the fit, is used from a database of different types of QFs and companies 112 - 14J, the rate and efficiency of measurements can be improved. Considering the fact that the approximate value of the MBBS maximum is detected at the initial steps of the calculation process, a pre-testing pattern of the strain distribution in the OF can be obtained quickly.
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 Ho. 8. 9334.2017/H. 9).
1, Bogachkov 1. V-, Gorlov N. I, 12013). Methods am! mcMa of monitoring ami tairfy diagnostics of fiber-optical transmission lines, Omsk: Publishing house OmSTlj. 192 p.
2. Bogachkov I. V. (2019). Ihe detection of pre-crash sections of the optic ill libers using the lirillouin reflecto me trv method. Dynamics of Systems, MechanisttM aod Machines, Dynamics 2018; proceedings. Journal of Physic*: Con/irencc Series, pp. 1-11.
.1. ! .isrvin A v.. I istvin V. N. (20(15). Refleetomtiry tífcomntmiealion optica!fibers. Moscow t.t;SARart. 20X p.
4, AQ S(iD3. Optical liber strain analy/er. Instruction manual AS-62577, - Japan. Ando Electric Co I.id.. 201)1. I'M p.
5. Viavi MTS/T-BERD 8000 - fiber sensing module DTSS module: user manual. Viavi Solutions. 94 p.
G. Bogachkov I. V. 12018). Patent of Russia on the use fill model I №277. G 01 N 21'27. lirillouin optical time domain re 11 eel o meter for monitoring optical libers. 2(11 íí 1353.83/28(05829!), publ. 09.10.201 it.
7. Bogachkov I. V. (2018). Patent of Russia on the useful model 186231. G (II N 21/27. Optical Briliouin re Hectometer. 2018135635/28(058643), publ. HI.IU.2018.
K. Bogachkóv I. V. (2018). Determination óf mechanical stressed places ol' optical libers in optical cables using Brill on in re Hectometers. T-Comm. vol. 12, no. 12, pp. 78-83.
9, Bogachkov 1. V„ Trukhina A, I,. Gorlov N, I. (2019}. Detection ol"optica I líber segments uilh mechanical stress in optical cables using lirillouin re Hectometers. International Siberian Conference on Control and Communications (SIBCON-2Q19}, Tomsk, pp. t-6.
10, Bogachkov 1. V (2017). Temperature Dependences of Mandelsiam Briliouin Sackscatter Spectrum in Optical l iben, of Various Types. Systems of Signal Synchronization, Generating and Processing in Telecommunications (SINKHR&1NFO-2017). Kazan, pp. l-(i.
11 Belal M., New so it 1. I'. |20I2). Experimental examination of the vari* ation of the spontaneous Briliouin power and frequency coefficients under the combined influence of temperature and strain. Journal ol Lighm-ave Technology, vol. 30. no, 8, pp. 1350-1255.
12. Bogachkov I. V.. Trulchina A, I., tnivatov D. P.. Kireev A, I'.. Gorlov N. I. (2019). A classification of optical libers types on the spectrum profile of the Mandelsiam - Briliouin hackse a tiering. Dynamics of Systems, Mechanism* and Machines-, Dynamics20 ¡8: proceedings. Journal of Physics: Conference Series, pp. 1-6.
13. Bogachkov I V., Inivatov D. P.. I'huban A. G. (2018). Certificate 23734 of electronic resource registration. Program lor automatical l\ detection the of optical fiber types on Briliouin traces (Russia, OmSTt I), publ. 14.08.2018.
14. Bogachkov I. V (2019). Cerli I kale 2019610752 of stale registration of computer programs. Program tor classification of uptieal fiber kinds on Briliouin n: Hectograms (Russia, OmSTU). 2018662391.07.11.201K. publ. 18.01.2019.
References
УЛУЧШЕНИЕ АЛГОРИТМОВ ОБРАБОТКИ ДАННЫХ В БРИЛЛЮЭНОВСКИХ РЕФЛЕКТОМЕТРАХ ПРИ ОПРЕДЕЛЕНИИ НАТЯЖЕНИЯ ОПТИЧЕСКИХ ВОЛОКОН
Богачков Игорь Викторович, Омский государственный технический университет (ОмГТУ), Омск, Россия, bogachkov@mail.ru
Работа выполнена при финансовой поддержке Министерства образования и науки РФ в рамках базовой части государственного задания в сфере научной деятельности (проект № 8.9334.2017/8.9)
Аннотация
Для организаций, эксплуатирующих волоконно-оптические линии связи (ВОЛС), актуальными являются задачи мониторинга и ранней диагностики оптических волокон (ОВ). Своевременное обнаружение участков с изгибами, трещинами, с повышенными механическими натяжениями, с изменённой температурой позволяет избежать постепенной деградации и разрушения ОВ ВОЛС. Специализированные приборы - бриллюэновские оптические импульсные рефлектометры (БОИР) - позволяют обнаруживать участки ОВ, находящихся в проложенных оптических кабелях, с повышенным продольным натяжением и изменённой температурой. Обычные оптические импульсные рефлектометры для решения таких задач не предназначены. В БОИР анализируется обратно отражённый сигнал, содержащий компоненты рассеяния Мандельштама - Бриллюэна. Процесс определения бриллюэновского сдвига частоты в световоде, а затем продольного натяжения вдоль ОВ, происходит очень медленно. Поэтому актуальной является задача совершенствования схем приборов для ранней диагностики ВОЛС и алгоритмов обработки с целью ускорения получения итоговых результатов. Обсуждены структурные схемы приборов для ранней диагностики оптических волокон. Процесс определения максимума СРМБ можно существенно ускорить, если сделать процессы измерений и обработки данных адаптивными за счёт специального выбора шага по частоте сканирования и времени накопления результатов измерений. Представленные в данном исследовании алгоритмы позволяют повысить скорость получения итоговых результатов в БОИР за счёт прореживания и игнорирования отсчётов, которые не оказывают влияния на итоговый результат. Если на некотором шаге процесса максимум СРМБ для определённой продольной координаты обнаружен, то параллельно основному процессу можно запустить процесс определения натяжения ОВ и построения картины его распределения вдоль световода. На следующих шагах результаты будут уточняться. Появление предварительной картины натяжения позволяет опытному пользователю БОИР прервать процесс измерений для внесения корректировок в установки измерений (изменение диапазона и шага сканирования по частоте, изменение разрешения и дистанции измерения по расстоянию и т. п.), что также позволяет уменьшить время тестирования. Другим способом ускорения процесса определения является адаптивное изменение времени накопления результатов измерений (количества усреднений). При использовании из базы данных шаблонов бриллюэновских рефлектиограмм ОВ различных типов и производителей можно повысить скорость и эффективность измерений. Поскольку примерное значение максимума СРМБ выявляется на начальных шагах вычислительного процесса, предварительную картину распределения натяжения в ОВ можно получить достаточно быстро.
Ключевые слова: оптическое волокно, натяжение, рассеяние Мандельштама — Бриллюэна, бриллюэновская рефлектометр, бриллюэновский сдвиг частоты.
Литература
1. Богачков И.В., Горлов Н.И. Методы и средства мониторинга и ранней диагностики волоконно-оптических линий передачи: монография. Омск: Изд-во ОмГТУ, 2013. 192 с.
2. Богачков И.В. Обнаружение предаварийных участков оптических волокон с помощью метода бриллюэновской рефлектометрии // Динамика систем, механизмов и машин. 2018. Т. 6, № 4. С. 88-95.
3. Листвин А.В., Листвин В.Н. Рефлектометрия оптических волокон связи. М.: ЛЕСАРарт, 2005. 208 с.
4. AQ 8603. Optical fiber strain analyzer. Instruction manual AS-62577. Japan, Ando Electric Co Ltd. 2001. 190 p.
5. Viavi MTS/T-BERD 8000 - fiber sensing module DTSS module: user manual. Viavi Solutions. 94 p.
6. Пат. на полезную модель 186277 Российская Федерация, МПК G 01 N 21/27. Оптический бриллюэновский рефлектометр для систем мониторинга оптических волокон / И. В. Богачков ; ОмГТУ. 2018135383/28(058291); заявлено 09.10.2018 ; опубл. 15.01.2019, Бюл. № 2.
7. Пат. на полезную модель 186231 Российская Федерация, МПК G 01 N 21/27. Оптический бриллюэновский рефлектометр / И. В. Богачков; ОмГТУ. 2018135635/28(058643); заявлено 10.10.2018; опубл. 11.01.2019, Бюл. № 2.
8. Богачков И.В., Горлов Н.И. Поиск предаварийных участков в оптических волокнах с помощью рефлектометров // Вестник СибГУТИ. Новосибирск: Изд-во СибГУТИ, 2018. Вып. 3 (43). С. 34-44.
9. Богачков И.В., Горлов Н.И. Обнаружение механически напряжённых участков оптических волокон в оптических кабелях с помощью бриллюэновских рефлектометров // Вестник СибГУТИ. 2019. Вып. 1 (45). С. 32-41.
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11. Belal M., Newson T.P. 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. 2012. Vol. 30, no. 8, рр. 1250-1255.
12. Богачков И.В., Трухина А.И., Иниватов Д.П., Киреев А.П., Горлов Н.И. Классификация оптических волокон по профилю спектра рассеяния Мандельштама - Бриллюэна // Динамика систем, механизмов и машин. 2018. Т. 6, № 4. С. 96-100.
13. Свидетельство о регистрации электронного ресурса 23734. Программа для автоматического определения типа оптического волокна по бриллюэновской рефлектограмме / И. В. Богачков, Д. П. Иниватов, А. Г. Чобан (Россия, ОмГТУ); опубл. 14.08.2018.
14. Свидетельство о гос. регистрации программы для ЭВМ 2019610752. Программа для классификации разновидностей оптических волокон по бриллюэновским рефлектограммам / И. В. Богачков (Россия, ОмГТУ). 2018662391; заявлено 07.11.2018; опубл. 18.01.2019.
Информация об авторе:
Богачков Игорь Викторович, к.т.н., доцент; доцент кафедры "Средства связи и информационная безопасность" Омского государственного технического университета (ОмГТУ), Senior Member IEEE, Омск, Россия
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