WO2020022921A1 - Procédé et dispositif de mesure répartie de biréfringence dans les fibres avec maintien de polarisation (et variantes) - Google Patents

Procédé et dispositif de mesure répartie de biréfringence dans les fibres avec maintien de polarisation (et variantes) Download PDF

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Publication number
WO2020022921A1
WO2020022921A1 PCT/RU2018/000486 RU2018000486W WO2020022921A1 WO 2020022921 A1 WO2020022921 A1 WO 2020022921A1 RU 2018000486 W RU2018000486 W RU 2018000486W WO 2020022921 A1 WO2020022921 A1 WO 2020022921A1
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Prior art keywords
frequency
optical
fiber
polarization
radiation
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PCT/RU2018/000486
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English (en)
Russian (ru)
Inventor
Рудольф Фридрихович ГЕЙДЕР
Михаил Владимирович ГРЕКОВ
Андрей Александрович ФОТИАДИ
Алексей Владимирович ШУБИН
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Общество с ограниченной ответственностью "Уникальные волоконные приборы" (ООО "УВП")
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Priority to PCT/RU2018/000486 priority Critical patent/WO2020022921A1/fr
Publication of WO2020022921A1 publication Critical patent/WO2020022921A1/fr

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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
    • G01J9/00—Measuring optical phase difference; Determining degree of coherence; Measuring optical wavelength
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
    • G01M11/00—Testing of optical apparatus; Testing structures by optical methods not otherwise provided for
    • G01M11/02—Testing optical properties

Definitions

  • the invention relates to fiber optics, in particular, to distributed fiber-optic sensors, in which the parameters of an optical fiber under the influence of external physical fields are measured.
  • PM fibers polarized conservation fibers
  • SBS-based commercial sensors implement methods for distributed monitoring of physical fields, for example, temperature and longitudinal tension, based on measuring SBS resonance parameters (see publications X. Bao, Q. Yu, and L. Chen, “Simultaneous strain and temperature measurements with polarization-maintaining fibers and their error analysis by use of a distributed Brillouin loss system,” Opt. Lett. 29, 1342-1344; X. Liu and X. Bao, “Brillouin Spectrum in LEAF and Simultaneous Temperature and Strain Measurement, ”IEEE J.of Lightwave Techn. 30, 1053-1059; L. Zou, X. Bao, SAV, and L.
  • the pulse signal passing through the fiber interacts during the SBS with a continuous signal, causing local changes in its intensity, which is most effective near resonance:
  • w * w * 0 - the resonant frequency of the pump signal
  • a change in the intensity of a continuous signal transmitted through the fiber is recorded by the sensor as a function of time and frequency difference W 0 .
  • the spatial-frequency characteristics of the SBS resonance are determined, namely, the spatial distribution of the SBS gain g 0 (x) (or the SBS gain line width ⁇ 5W (c)), the Brillouin frequency shift W 0 (c ), the position of the peaks of the SBS resonances in fibers with several resonances.
  • the device comprises a low-coherent laser emitting continuous wave light with a pump frequency a) L , a power divider, a measuring directional coupler, the output of the main channel of which is connected to the proximal end of the fiber of the optical cable connected by the opposite end to the optical reflector, the branch arm output measuring directional coupler connected to the input of the photodetector connected by the output to the input of the processor processing the result measurements, characterized in that the output of the low-coherent laser is connected to the output of the passage arm of the first directional coupler, the output of the main channel of which is connected to one output of the active medium element with the effect of stimulated Raman scattering, the Stokes displacement frequency in which is equal to the Stokes displacement frequency in the studied fiber, the second the output of the specified element is connected to the output the main channel of the second directional coupler, the output of the passage arm of which is connected to the first input of the power divider connected by the second output to the first input of the optical adder, and
  • the device comprises a low-coherent laser emitting continuous wave light with a pump frequency co L , connected by an output to the input of a power divider, a measuring directional coupler, the output of the main channel of which is connected to the near end of the fiber of the optical cable, the branch of the measuring arm of the measuring directional coupler is connected with the input of the photodetector connected by the output to the input of the processor that processes the measurement results, differing in those m, that the first output of the power divider is connected to the input of a controlled optical shutter, the output of which is connected to the output of the passage arm of the measuring directional coupler, the opposite end of the test fiber is connected to the first output of the second power divider connected to the second output to the output of the passage of the first directional coupler, the output of the main the channel of which is connected to the opposite end of the first additional fiber of the optical cable connected by the proximal end to the output of the main channel of the second directional power coupler, the lead of the passage
  • the technical result is to increase the accuracy and expansion of functionality by using the scattering of both Brillouin and Raman.
  • the distributed measurement of birefringence in fibers with conservation of polarization described in the aforementioned patent cannot be realized by methods using BOTDA based on the SBS interaction of optical signals at two frequencies.
  • This method of distributed measurement of birefringence in fibers while maintaining polarization using a Brillouin dynamic grating is based on the reflection of the probing signal from a dynamic sound grating, formed during SBS interaction of two counterpropagating light waves in RM fibers.
  • the essence of the known method lies in the fact that not two, but three optical narrow-band linearly polarized signals are introduced into a segment of an optical RM fiber.
  • Stokes w * 0 shifted relative to each other by the resonant SBS of the shift W 0 , are introduced into the fiber from opposite ends in the polarization of one of the main axes of the fiber. Their interaction in the fiber leads to the formation of a dynamic lattice of a sound wave propagating along the entire region of signal interaction.
  • a probing, or probe, pulse (or signal) is tuned into the fiber, tunable in frequency w shifted relative to the fundamental pump frequency.
  • w £ 0 and w 0 are the optical frequency of the main pump and the resonant optical frequency of the probing signal
  • n x and h g are the refractive indices of the fundamental polarization modes of the fiber
  • C is the speed of light in vacuum and sound in the fiber.
  • An object of the present invention is to reduce the number of optical fiber polls required to record the spatial distribution of birefringence in optical fibers while maintaining polarization.
  • the technical result is to reduce the measurement time of the test site (with a fixed range of birefringence measurements) and increase the dynamic range of measurements of birefringence (with a fixed measurement time of the test site).
  • the specified technical result is achieved by the fact that in the proposed method for distributed measurement of birefringence in optical fibers with preservation of polarization in comparison with the known when conducting a single measurement of two counterpropagating optical signals propagating in the same polarization of the fiber at frequencies o and eo * at least partial excitation of the hypersonic wave is provided -W 0
  • the result can also be achieved by the method of distributed measurement of birefringence in optical fibers with preservation of polarization in which, in comparison with the known, when single measurement by two opposing optical signals propagating in the same polarization of the fiber at frequencies eo and co * provides at least partial excitation of the hypersonic wave co * -w * -W 0
  • the inventive device designed to implement the method of distributed measurement of birefringence in optical fibers while maintaining polarization consists of an optical generator, one polarizing combiner, a polarizing divider, a PM circulator, an optical fiber, at least one detector, a device for instantaneous measurement of the frequency of an optical signal, processor.
  • the mentioned optical generator generates narrow-band optical radiation at frequencies w *, co * in the vicinity of frequencies, respectively, co 0 , w * 0 and broadband radiation with a central frequency co L Y and a spectral band
  • Said device for instantaneous measurement of the frequency of optical radiation instantly measures the peak frequency of the spectrum of the optical radiation scattered from the fiber in polarization Y and the transmission of this information as a function of the time the signal arrives at the processor for further processing.
  • Figure 1 shows a typical example of the arrangement of the resonant frequencies of interacting optical signals for a wavelength of -1550 nm (above) and a signal input circuit into the fiber while maintaining polarization.
  • figure 2. a schematic diagram of the inventive device.
  • Fig. 3 shows a schematic diagram of an optical generator.
  • Figure 4 shows a schematic diagram of a device for instantaneous measurement of optical frequency.
  • Figure 5 shows an example of the measured spectra of signals obtained by the known (red curve) and the claimed (black curve) method (left) and an example of approximating the measured spectrum of the Lorentz curve (right).
  • Figure 6 shows the experimentally measured dependence of the resonant frequencies of H 0 (left, red curve is a known method, black curve is the inventive method) and W 0 (right) from the pressure in the pressure chamber.
  • the inventive method is based on the characteristics of the dynamics of stimulated scattering of Mandelyntam-Brillouin (SBS) in optical fibers with preservation of polarization (PM fibers) and the special susceptibility of this process to local variations of birefringence (including under the influence of measured external influences), determined by detection and mathematical processing of signals received from the output of the fiber during amplitude modulation and frequency scanning of the master optical fields.
  • SBS Mandelyntam-Brillouin
  • PM fiber conventional optical fibers with conservation of polarization
  • specially designed PM fibers and / or PM fibers enclosed in a specially designed cable in both cases providing selective sensitivity of the induced birefringence to the measured external field .
  • the method has advantages in systems designed for distributed measurement of two or more types of external influences (in combinations with other methods), as well as in cases where it is necessary to provide better spatial resolution, measurement accuracy and (or) the range of the tested area, in comparison with known methods.
  • the inventive variant of the device implements the proposed method.
  • radiation at the pump frequencies w and the Stokes signal w * is introduced into the segment of the optical fiber from opposite ends in the polarization of one of the main axes of the fiber with an effective refractive index n x .
  • a probing signal at a frequency cJ L is co-directional with a signal at a frequency introduced into the polarization of the other main axis of the fiber with an effective refractive index h g .
  • Radiation at frequencies co and co * is narrow-band, and at frequency a> broadband with a known optical spectrum, including the resonant frequency k> 0 , determined by condition (2).
  • the spatial distribution of the scattered signal frequency oJ s along the fiber is measured.
  • the distribution of An is reproduced from the frequency of the scattered signal w and the known quantity ⁇ * by formula (5).
  • Other resonance characteristics can also be used as independent parameters for measuring external influences.
  • a significant difference between the proposed method of distributed measurement of birefringence in optical fibers with preservation of polarization from those known from the prior art is the use of a broadband signal at a fixed frequency w with a spectral width that at least partially covers the region of change of resonance w 0 along the fiber and measures the instantaneous frequency co s Y of the optical signal scattered from the fiber. This avoids the time-consuming procedure of scanning the interrogating signal by frequency and, thus, reduces the measurement time of the test section (with a fixed birefringence measurement range) or increases the dynamic range of birefringence measurements (with a fixed measurement time of the tested section).
  • a polarizing combiner is a well-known fiber-optic element that provides the combination of linear polarizations from two input fibers while maintaining polarization in two orthogonal polarizations of one output fiber while maintaining polarization.
  • radiation at the frequency co * is introduced into the X-polarization of the output fiber of the polarizing combiner 1, and radiation at the frequency co] into the Y-polarization of the output fiber of the polarizing combiner 1.
  • a fiber optic polarizing combiner is optically coupled to a fiber optic PM circulator.
  • PM circulator is a well-known fiber-optic element, which ensures the conservation of polarization and decoupling of radiation coming from opposite inputs.
  • the fiber-optic output of the generator at a frequency wz is optically coupled by the X polarization of the optical fiber acting as a sensitive element.
  • the optical fiber used can be any polarization-preserving fiber (for example, of the PANDA type), which is sensitive to changes in physical parameters (temperature, longitudinal tension, surface pressure) determined by recording the value of the resonance shift R 0 .
  • a polarization divider transmits radiation in orthogonal polarizations to two optical channels corresponding to two polarizations X and Y.
  • the optical signal from channel X is converted by a fast selective photodetector into an electrical signal, which is fed to the processor for accumulation, mathematical processing, and extraction of information about the spatial distribution of the tested parameter W 0 .
  • the optical signal from channel U enters an instantaneous frequency measurement device that converts the input radiation into a digital signal containing information about the instantaneous frequency of the input optical radiation w as a function of the time the radiation arrives at the device, which enters the processor to accumulate, mathematically process, and extract spatial information the distribution of the test parameter H.
  • the processor ensures the synchronous operation of all elements of the system: sets the moment of emission, the shape and intensity of the pulses of the optical signals in the optical radiation generator, the collection and processing of signals from the photodetector and instant frequency measurement device (MIC).
  • Fig. 3 shows a diagram of an optical radiation generator based on tunable distributed feedback semiconductor lasers.
  • the lasers are tunable semiconductor lasers of the RIO type (see htp: //www.rio-inc.com/), in which the electronic tuning and stabilization of the laser frequencies relative to the master laser is provided.
  • All lasers are optically coupled to fiber amplifiers and electro-optical modulators, which provide, by means of a synchronizer, the time-synchronized generation of pulses of a given shape and intensity, arriving at the three fiber-optic outputs of the generator, made on fibers with preservation of polarization.
  • the modulator 3 forms the spectrum of the output signal at a frequency w.
  • Figure 4 presents a diagram of a device for instantaneous measurement of the frequency of optical radiation, made on the basis of a narrow-band semiconductor laser with distributed feedback, a fast selective photodetector and means for instantly measuring the frequency of an RF signal.
  • the laser is a narrow-band semiconductor laser similar to the aforementioned, in which the electronic means provides tuning and stabilization of the frequency relative to the master laser.
  • the device is equipped with an optical fiber PM coupler that removes the radiation of a semiconductor laser at a frequency w ⁇ g and directs it directly to a fast photodetector for registration together with the measured optical signal at a frequency w g .
  • the radio frequency signal generated by the photodetector is fed to a known device for instantly measuring the frequency of a radio signal, which real-time processes the spectrum of the radio frequency signal and generates a digital signal containing information about the frequency of the incoming radio frequency signal as a function of time that is transmitted to the processor.
  • the absolute instantaneous frequency of the optical signal is determined by the frequency of the recorded radio signal according to the well-known laws of coherent detection.
  • the claimed device is universal, because in addition to implementing the claimed variants of the method based on the four-frequency SBS interaction in the fiber, also allow you to implement the above-mentioned, known from the prior art methods of distributed measurement of birefringence in optical fibers with preservation of polarization, based on two- and three-frequency interaction.
  • the signal at a frequency ⁇ o L Y is broadband, and birefringence is determined by the instantaneous frequency scattered from the fiber signal in the polarization Y, the following are the results of an experimental demonstration of the claimed device.
  • a piece of PM fiber (Panda, Fujikura) with a length of 520 m was used in the experiment.
  • a fiber section at a length of 250 m was placed in a heat-stabilized (25 ° C) pressure chamber.
  • the length of the fiber section placed in the pressure chamber was ⁇ 6 m.
  • the pressure in the pressure chamber varied from 1 to 80 MPa, which led to a local change in birefringence in the fiber segment enclosed in the pressure chamber.
  • the measurement scheme made it possible to directly compare the number of surveys needed to implement the known and proposed method for measuring the magnitude of the difference in refractive index (surface pressure).
  • the measurement scheme was as follows.
  • the narrow-band signal at a frequency w * was a pulse of ⁇ 50 ns in duration and an amplitude of ⁇ 1 W.
  • the narrow-band signal at a fixed frequency w * 0 was a -300 mW continuous radiation.
  • the signal at a frequency co L Y was a pulse with a duration of ⁇ 25 ns and a power of ⁇ 300 mW; its delay relative to the leading edge of the pulse at a frequency of wz was ⁇ 25 ns.
  • the optical bandwidth of the signal at a frequency a> was controlled by an optical phase modulator (up to 5 GHz) by applying a broadband radio signal to the modulator.
  • the measurement procedure for a single fiber section was as follows. At first, a signal at a frequency co] was not supplied to the fiber, and measurements were made repeatedly by scanning the frequency co * and measuring the intensity of the output signal at a frequency w recorded by a photo detector. From the maximum of this signal, the resonance frequency W 0 was determined, which is described by expression (1).
  • the fiber was repeatedly interrogated by a pulsed signal at a frequency co], with a non-expanded lasing band ( ⁇ 100 kHz).
  • the frequency ⁇ ] was scanned within 2 GHz in steps of ⁇ 4 MHz.
  • the intensity of the signal I S Y () scattered from the fiber into
  • characteristic time t 0 60 ns, which corresponds to the selected spatial resolution t 0 s / n ⁇ 6 m.
  • the fiber was interrogated by a signal at a frequency Mandarin, with a spectral band broadened to -3 GHz by a special radio signal supplied to modulator 3 ( Figure 2).
  • An instantaneous measurement of the optical frequency of a signal scattered from a fiber in a polarization U it was mixed with a signal from a laser at a frequency co] in a polarization U on a fast photo detector and was recorded by a fast oscilloscope. In every short the time span of the response signal was observed in the time base of the oscilloscope as a beat signal of two optical signals at the difference frequency .
  • the signal digitized by an oscilloscope with a step of ⁇ 0.5 ns was subjected to spectral analysis at each time interval of 60 ns and the measured spectrum was averaged over 25 identical fiber polls.
  • the averaged spectrum was approximated by the Lorentz curve in order to determine the instantaneous peak frequency of the radio signal q ( ⁇ ).
  • the spatial resolution in this case was -6 m.
  • the described procedure required -25 single changes.
  • the number of fiber polls (and accordingly the total polling time) required for measurements in the inventive method is 20 times less than in the known one.
  • This indicator can be further increased by broadening the bandwidth of the interrogation signal at the frequency co L Y and the use of higher-speed means for instantly measuring the frequency of the optical signal.
  • the proposed method can significantly reduce the number of optical fiber polls required for measuring distributed birefringence and, accordingly, reduce the measurement time of the test site (with a fixed birefringence measurement range) and increase the dynamic measurement range of birefringence (with a fixed measurement time of the test site). In turn, this allows to increase the accuracy of measurements, and to increase the length of the test section.

Abstract

L'invention concerne l'optique des fibres et notamment des capteurs à fibre optique répartis dans lesquels on mesure des paramètres de la fibre optique qui est soumise à l'influence de champs physiques externes. Dans ce procédé de mesure répartie de la biréfringence dans des fibres optiques, on utilise en qualité de rayonnement de sondage un rayonnement ayant une composition spectrale connue, et la détermination de la biréfringence dans la fibre se fait à une fréquence instantanée du rayonnement diffusé à l'encontre du signal de sondage. Ce procédé permet d'augmenter sensiblement le nombre de tests de la fibre optique nécessaires pour mesurer la biréfringence répartie, et permet ainsi de réduire le temps de mesure de la section testée (dans une plage de mesures fixe de la section testée) et d'augmenter la plage dynamique des mesures de biréfringence (dans un temps de mesure fixe de la section testée). Ce procédé est mis en oeuvre par un dispositif de mesure répartie de la biréfringence dans des fibres optiques avec un maintien de la polarisation. Le résultat technique consiste en une diminution du temps de mesure de la section testée (dans une plage de mesure fixe de la biréfringence) et une augmentation de la plage dynamique des mesures de biréfringence (dans un temps de mesure fixe de la section testée).
PCT/RU2018/000486 2018-07-23 2018-07-23 Procédé et dispositif de mesure répartie de biréfringence dans les fibres avec maintien de polarisation (et variantes) WO2020022921A1 (fr)

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Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113810248A (zh) * 2021-09-16 2021-12-17 中国电子科技集团公司第五十四研究所 一种面向分布式时频链路信号同步性能的测试与评估方法
CN114978307A (zh) * 2022-05-20 2022-08-30 北京交通大学 一种基于保偏光纤双折射效应的单支路探测瞬时频率测量系统

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7463346B2 (en) * 2005-04-14 2008-12-09 Fujikura Ltd. Optical fiber birefringence measurement method and measurement device, and optical fiber polarization mode dispersion measurement method and optical fiber
CN102589857A (zh) * 2012-03-08 2012-07-18 哈尔滨工业大学 基于布里渊动态光栅的分布式保偏光纤双折射测量方法及装置
RU2539849C2 (ru) * 2013-04-17 2015-01-27 Общество с ограниченной ответственностью "Уникальные волоконные приборы" Способ и устройство распределенного измерения двулучепреломления в волокнах с сохранением поляризации (варианты)
RU2627018C1 (ru) * 2016-07-18 2017-08-02 Федеральное государственное унитарное предприятие "Центр эксплуатации объектов наземной космической инфраструктуры" Радиационно-стойкий одномодовый световод с большим линейным двулучепреломлением для волоконно-оптического гироскопа

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7463346B2 (en) * 2005-04-14 2008-12-09 Fujikura Ltd. Optical fiber birefringence measurement method and measurement device, and optical fiber polarization mode dispersion measurement method and optical fiber
CN102589857A (zh) * 2012-03-08 2012-07-18 哈尔滨工业大学 基于布里渊动态光栅的分布式保偏光纤双折射测量方法及装置
RU2539849C2 (ru) * 2013-04-17 2015-01-27 Общество с ограниченной ответственностью "Уникальные волоконные приборы" Способ и устройство распределенного измерения двулучепреломления в волокнах с сохранением поляризации (варианты)
RU2627018C1 (ru) * 2016-07-18 2017-08-02 Федеральное государственное унитарное предприятие "Центр эксплуатации объектов наземной космической инфраструктуры" Радиационно-стойкий одномодовый световод с большим линейным двулучепреломлением для волоконно-оптического гироскопа

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113810248A (zh) * 2021-09-16 2021-12-17 中国电子科技集团公司第五十四研究所 一种面向分布式时频链路信号同步性能的测试与评估方法
CN113810248B (zh) * 2021-09-16 2023-12-29 中国电子科技集团公司第五十四研究所 一种面向分布式时频链路信号同步性能的测试与评估方法
CN114978307A (zh) * 2022-05-20 2022-08-30 北京交通大学 一种基于保偏光纤双折射效应的单支路探测瞬时频率测量系统
CN114978307B (zh) * 2022-05-20 2023-09-01 北京交通大学 一种基于保偏光纤双折射效应的单支路探测瞬时频率测量系统

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