KR101715812B1 - optical sensor system - Google Patents

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KR101715812B1
KR101715812B1 KR1020150088481A KR20150088481A KR101715812B1 KR 101715812 B1 KR101715812 B1 KR 101715812B1 KR 1020150088481 A KR1020150088481 A KR 1020150088481A KR 20150088481 A KR20150088481 A KR 20150088481A KR 101715812 B1 KR101715812 B1 KR 101715812B1
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optical
signal
optical fiber
frequency
signal output
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KR20160150458A (en
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김영호
김명진
노병섭
정은주
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한국광기술원
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    • 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
    • G01M11/30—Testing of optical devices, constituted by fibre optics or optical waveguides
    • G01M11/31—Testing of optical devices, constituted by fibre optics or optical waveguides with a light emitter and a light receiver being disposed at the same side of a fibre or waveguide end-face, e.g. reflectometers
    • G01M11/3172—Reflectometers detecting the back-scattered light in the frequency-domain, e.g. OFDR, FMCW, heterodyne detection
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
    • G01B11/00—Measuring arrangements characterised by the use of optical techniques
    • G01B11/16—Measuring arrangements characterised by the use of optical techniques for measuring the deformation in a solid, e.g. optical strain gauge
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
    • G01D5/00—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable
    • G01D5/26—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light
    • G01D5/32—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light
    • G01D5/34—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells
    • G01D5/353—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells influencing the transmission properties of an optical fibre
    • G01D5/35338—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells influencing the transmission properties of an optical fibre using other arrangements than interferometer arrangements
    • G01D5/35354—Sensor working in reflection
    • G01D5/35358—Sensor working in reflection using backscattering to detect the measured quantity
    • G01D5/35364—Sensor working in reflection using backscattering to detect the measured quantity using inelastic backscattering to detect the measured quantity, e.g. using Brillouin or Raman backscattering
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01K—MEASURING TEMPERATURE; MEASURING QUANTITY OF HEAT; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR
    • G01K11/00—Measuring temperature based upon physical or chemical changes not covered by groups G01K3/00, G01K5/00, G01K7/00 or G01K9/00
    • G01K11/32—Measuring temperature based upon physical or chemical changes not covered by groups G01K3/00, G01K5/00, G01K7/00 or G01K9/00 using changes in transmittance, scattering or luminescence in optical fibres
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B26/00—Optical devices or arrangements for the control of light using movable or deformable optical elements
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/24—Coupling light guides
    • G02B6/26—Optical coupling means
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/24—Coupling light guides
    • G02B6/26—Optical coupling means
    • G02B6/27—Optical coupling means with polarisation selective and adjusting means
    • G02B6/2746—Optical coupling means with polarisation selective and adjusting means comprising non-reciprocal devices, e.g. isolators, FRM, circulators, quasi-isolators

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Abstract

본 발명은 브릴루앙 산란기반 분포형 광섬유 센서 시스템에 관한 것으로서, 주파수가 가변되는 광을 출사하는 주파수 가변 광원과, 광원에서 출력되는 신호를 제1분할신호와 제2분할신호로 분할하는 메인 광분할기와, 입력단을 통해 입력된 제1분할신호를 센싱 광섬유에 출력하고, 센싱 광섬유에서 반사된 광을 제1출력단을 통해 출력하는 광써큘레이터와, 메인 광분할기에서 출력되는 제2분할신호를 전송하는 기준광섬유와, 기준 광섬유 상에 결합되어 제2분할신호를 변조한 변조신호를 생성하여 출력하는 광변조부와, 메인 광분할기로부터 기준광섬유 및 광변조부를 경유하여 전송된 변조신호와 제1출력단을 통해 출력되는 신호를 커플링하여 출력하는 제1광커플러와, 제1광커플러에서 출력되는 신호에 대해 브릴루앙 산란신호에 대응되게 설정된 대역의 신호를 필터링하여 출력하는 필터와, 필터를 거쳐 출력되는 신호를 검출하는 광검출부와, 변조신호의 주파수가 가변되게 광변조부를 제어하면서 광검출부에서 출력되는 신호로부터 센싱광섬유에 대해 측정하고자 하는 물리량을 산출하는 측정부를 구비한다. 이러한 브릴루앙 산란기반 분포형 광섬유 센서 시스템에 의하면, 센싱광섬유로부터 산란된 브릴루앙 산란신호의 수신감도를 높여 측정할 수 있는 장점을 제공한다.The present invention relates to a Brillouin scattering-based optical fiber sensor system, and more particularly, to a Brillouin scattering-based optical fiber sensor system that includes a frequency variable light source for emitting light with variable frequency, a main light splitter for dividing a signal output from the light source into a first divided signal and a second divided signal, An optical circulator for outputting a first divided signal inputted through an input terminal to a sensing optical fiber and outputting the light reflected from the sensing optical fiber through a first output terminal and a second circulator for transmitting a second divided signal output from the main optical splitter A reference optical fiber, a light modulator coupled to the reference optical fiber to generate and output a modulated signal obtained by modulating the second divided signal, and a modulated signal transmitted from the main optical splitter via the reference optical fiber and the optical modulator, A first optical coupler for coupling and outputting a signal output through the first optical coupler, And a control unit for controlling the optical modulator so as to vary the frequency of the modulated signal so as to detect a physical quantity to be measured for the sensing optical fiber from the signal output from the optical detector, And a measurement unit for calculating a measurement result. According to the Brillouin scattering-based optical fiber sensor system, the sensitivity of the scattered Brillouin scattering signal from the sensing optical fiber can be increased and the measurement can be performed.

Figure R1020150088481
Figure R1020150088481

Description

브릴루앙 산란기반 분포형 광섬유 센서 시스템{optical sensor system}Brillouin scattering-based optical fiber sensor system [

본 발명은 브릴루앙 산란기반 분포형 광섬유 센서 시스템에 관한 것으로서, 상세하게는 브릴루앙 산란 신호의 취득감도를 높일 수 있도록 된 브릴루앙 산란기반 분포형 광섬유 센서 시스템에 관한 것이다.The present invention relates to a Brillouin scattering-based optical fiber sensor system, and more particularly, to a Brillouin scattering-based distributed optical fiber sensor system capable of enhancing acquisition sensitivity of a Brillouin scattering signal.

광주파수영역 반사측정(OFDR) 시스템은 빛의 반사광을 이용하여 광섬유의 길이, 절단위치(fault position), 색분산(chromatic dispersion), 편광모드분산(polarization mode dispersion), 손실(loss) 등을 측정하는 시스템이다. Optical Frequency Domain Reflectometry (OFDR) systems use optical reflection of light to measure the length of a fiber, its fault position, chromatic dispersion, polarization mode dispersion, and loss .

OFDR시스템은 광시간영역반사측정(OTDR : optical time domain reflectometry) 시스템보다 분해능이 좋고 동적범위(dynamic range)가 넓어서 광통신과 광센서 분야에 응용되고 있다.The OFDR system has better resolution and dynamic range than optical time domain reflectometry (OTDR) system and is applied to optical communication and optical sensor fields.

이러한 OFDR시스템은 국내 공개특허 제10-2006-0102801호 등 다양하게 게시되어 있다.Such an OFDR system is variously disclosed in Korean Patent Laid-Open No. 10-2006-0102801.

한편, 광섬유에서 반사되는 산란광은 레일레이 산란광과 브릴루앙 산란광이 있으며, 레일레이 산란광은 브릴루앙 산란광에 비해 신호의 세기는 크지만 고주파로서 광검출기로 측정이 쉽지 않아 브릴루앙 산란광의 수집감도를 높일 수 있는 구조가 요구되고 있다.On the other hand, the scattered light reflected by the optical fiber has Rayleigh scattering and Brillouin scattering, and Rayleigh scattering has a stronger signal intensity than Brillouin scattering light, but measurement with a photodetector as a high frequency is not easy. A structure is required.

본 발명은 상기와 같은 요구사항을 해결하기 위하여 창안된 것으로서, 센싱광섬유로부터 발생되는 브릴루앙 산란광에 대한 수신 감도를 높일 수 있는 브릴루앙 산란기반 분포형 광섬유 센서 시스템을 제공하는데 그 목적이 있다. It is an object of the present invention to provide a Brillouin scattering-based optical fiber sensor system capable of increasing reception sensitivity to Brillouin scattering light generated from a sensing optical fiber.

상기의 목적을 달성하기 위하여 본 발명에 따른 브릴루앙 산란기반 분포형 광섬유 센서 시스템은 주파수가 가변되는 광을 출사하는 주파수 가변 광원과; 상기 광원에서 출력되는 신호를 제1분할신호와 제2분할신호로 분할하는 메인 광분할기와; 입력단을 통해 입력된 상기 제1분할신호를 센싱 광섬유에 출력하고, 상기 센싱 광섬유에서 반사된 광을 제1출력단을 통해 출력하는 광써큘레이터와; 상기 메인 광분할기에서 출력되는 제2분할신호를 전송하는 기준광섬유와; 상기 기준 광섬유 상에 결합되어 상기 제2분할신호를 변조한 변조신호를 생성하여 출력하는 광변조부와; 상기 메인 광분할기로부터 상기 기준광섬유 및 상기 광변조부를 경유하여 전송된 변조신호와 상기 제1출력단을 통해 출력되는 신호를 커플링하여 출력하는 제1광커플러와; 상기 제1광커플러에서 출력되는 신호에 대해 브릴루앙 산란신호에 대응되게 설정된 대역의 신호를 필터링하여 출력하는 필터와; 상기 필터를 거쳐 출력되는 신호를 검출하는 광검출부와; 상기 변조신호의 주파수가 가변되게 상기 광변조부를 제어하면서 상기 광검출부에서 출력되는 신호로부터 상기 센싱광섬유에 대해 측정하고자 하는 물리량을 산출하는 측정처리부;를 구비한다.According to an aspect of the present invention, there is provided a Brillouin scattering-based optical fiber sensor system comprising: a frequency variable light source for outputting variable-frequency light; A main beam splitter for dividing a signal output from the light source into a first divided signal and a second divided signal; An optical circulator outputting the first divided signal inputted through an input terminal to a sensing optical fiber and outputting the light reflected from the sensing optical fiber through a first output terminal; A reference optical fiber for transmitting a second split signal output from the main optical splitter; An optical modulator coupled to the reference optical fiber for generating and outputting a modulated signal modulated with the second divided signal; A first optical coupler coupling and outputting a modulation signal transmitted from the main optical splitter via the reference optical fiber and the optical modulator and a signal output through the first output terminal; A filter for filtering a signal output from the first optical coupler in a band corresponding to the Brillouin scattering signal; A photodetector for detecting a signal output through the filter; And a measurement processing unit for calculating a physical quantity to be measured with respect to the sensing optical fiber from a signal output from the optical detection unit while controlling the optical modulation unit so that the frequency of the modulation signal is varied.

상기 광변조부는 상기 제2분할신호에 대해 11GHz 내지 12GHz 범위내에서 주파수를 변조하도록 된 것이 바람직하다.And the optical modulator modulates the frequency within the range of 11 GHz to 12 GHz with respect to the second divided signal.

또한, 상기 광변조부와 상기 제1광커플러 사이에 마련되어 상기 광변조부에서 출력되는 신호와 상기 센싱광섬유의 종단을 통해 진행되는 광을 합파하여 상기 제1광커플러로 전송하는 제2광커플러;를 더 구비할 수 있다.A second optical coupler provided between the optical modulator and the first optical coupler for multiplexing a signal output from the optical modulator and light traveling through an end of the sensing optical fiber and transmitting the combined signal to the first optical coupler; As shown in FIG.

본 발명에 따른 브릴루앙 산란기반 분포형 광섬유 센서 시스템에 의하면, 센싱광섬유로부터 산란된 브릴루앙 산란신호의 수신감도를 높여 측정할 수 있는 장점을 제공한다.The Brillouin scattering-based distributed optical fiber sensor system according to the present invention provides an advantage of measuring sensitivity by increasing the reception sensitivity of the Brillouin scattering signal scattered from the sensing optical fiber.

도 1은 본 발명의 일 실시예에 따른 브릴루앙 산란기반 분포형 광섬유 센서 시스템을 나타내 보인 도면이고,
도 2는 본 발명의 또 다른 실시예에 따른 브릴루앙 산란기반 분포형 광섬유 센서 시스템을 나타내 보인 도면이다.1 is a view showing a Brillouin scattering-based distributed optical fiber sensor system according to an embodiment of the present invention,
FIG. 2 is a view showing a Brillouin scattering-based distributed optical fiber sensor system according to another embodiment of the present invention.

이하, 첨부된 도면을 참조하면서 본 발명의 바람직한 실시예에 따른 브릴루앙 산란기반 분포형 광섬유 센서 시스템을 더욱 상세하게 설명한다.Hereinafter, a Brillouin scattering-based distributed optical fiber sensor system according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

도 1은 본 발명의 일 실시예에 따른 브릴루앙 산란기반 분포형 광섬유 센서 시스템을 나타내 보인 도면이다.1 is a view showing a Brillouin scattering-based optical fiber sensor system according to an embodiment of the present invention.

도 1을 참조하면, 본 발명에 따른 광섬유 센서 시스템(100)은 주파수 가변 광원(120), 서브광분할기(131), 메인 광분할기(133), 광써큘레이터(137), 센싱광섬유(FUT)(140), 광변조기(145), 제1광커플러(150), 필터(160), 광검출기(170), 주파수 모니터링부(180), 측정부(190)를 구비한다.1, an optical fiber sensor system 100 according to the present invention includes a frequency variable light source 120, a sub-optical splitter 131, a main optical splitter 133, an optical circulator 137, a sensing optical fiber (FUT) A first optical coupler 150, a filter 160, a photodetector 170, a frequency monitoring unit 180, and a measuring unit 190. The first optical coupler 140, the optical modulator 145, the first optical coupler 150,

주파수 가변 광원(120)은 측정부(190)에 제어되어 주파수가 가변되는 광을 출사한다.The frequency variable light source 120 is controlled by the measurement unit 190 to emit light whose frequency is variable.

서브 광분할기(131)는 주파수 가변 광원(120)에서 출력되는 신호를 측정용과 모니터링용으로 분할하여 출력한다.The sub light splitter 131 divides the signal output from the frequency variable light source 120 for measurement and monitoring.

메인 광분할기(133)는 주파수 가변 광원(120)에서 서브 광분할기(131)를 거쳐 측정용으로 출력되는 신호를 제1분할신호와 제2분할신호로 분할하여 출력한다.The main optical splitter 133 divides the signal output from the frequency variable light source 120 through the sub-optical splitter 131 into a first divided signal and a second divided signal, and outputs the divided signal.

광서큘레이터(137)는 메인 광분할기(133)로부터 분할된 후 중계광섬유를 거쳐 입력단(137a)을 통해 입력된 제1분할신호를 센싱단(137b)를 통해 센싱 광섬유(140)에 출력하고, 센싱 광섬유(140)에서 반사되어 역으로 센싱단(137b)을 통해 입사된 광을 제1출력단(137c)을 통해 출력한다.The optical circulator 137 outputs the first divided signal inputted through the input terminal 137a through the relay optical fiber after being split from the main optical splitter 133 to the sensing optical fiber 140 through the sensing terminal 137b, And outputs the light reflected from the sensing optical fiber 140 and incident through the sensing end 137b through the first output end 137c.

센싱광섬유(140)는 광서큘레이터(137)의 센싱단(137b)에 일단이 접속되어 있다.One end of the sensing optical fiber 140 is connected to the sensing end 137b of the optical circulator 137.

도시된 예에서 센싱광섬유(140)의 종단은 오픈 상태로 되어 있고, 브릴루앙 산란신호의 수신감도를 높이기 위해 도 2에 도시된 바와 같이 타단이 제2광커플러(147)에 접속되게 구축될 수 있다.In the illustrated example, the terminating end of the sensing optical fiber 140 is in the open state and may be constructed so that the other end thereof is connected to the second optical coupler 147 as shown in FIG. 2 to increase the reception sensitivity of the Brillouin scattering signal have.

여기서 제2광커플러(147)는 광변조부(145)와 제1광커플러(150) 사이에 마련되어 광변조부(145)에서 출력되는 신호와 센싱광섬유(140)의 종단을 통해 진행되는 광을 합파하여 제1광커플러(150)로 전송하도록 되어 있다.The second optical coupler 147 is provided between the optical modulator 145 and the first optical coupler 150 so that the signal output from the optical modulator 145 and the light propagating through the end of the sensing optical fiber 140 Multiplexed and transmitted to the first optical coupler 150.

편광제어기(PC)는 인지도(visibility) 향상을 위해 기준광섬유(135)와 센싱광섬유(140)에 적용되어 있다.The polarization controller PC is applied to the reference optical fiber 135 and the sensing optical fiber 140 in order to improve the visibility.

기준광섬유(135)는 메인 광분할기(133)에서 출력되는 제2분할신호를 전송하도록 접속되어 있다.The reference optical fiber 135 is connected to transmit a second divided signal output from the main beam splitter 133. [

광변조부(145)는 측정부(190)에 제어되며, 기준 광섬유(135) 상에 결합되어 제2분할신호를 주파수가 이동되게 변조한 변조신호를 생성하여 출력할 수 있도록 되어 있다.The optical modulator 145 is controlled by the measuring unit 190 and is coupled onto the reference optical fiber 135 to generate and output a modulated signal obtained by modulating the second divided signal so that the frequency is shifted.

광변조부(145)는 브릴루앙 산란신호에 대응되는 변조신호가 생성되도록 구축되어 있다.The optical modulator 145 is constructed so that a modulated signal corresponding to the Brillouin scattering signal is generated.

참조부호 148은 광변조부에서 변조된 신호가 제2분할신호를 기준으로 동일 주파수 천이값이 양과 음의 방향에서 모두 생성되는 경우 하나를 제거하기 위해 적용된 보조 필터이다. Reference numeral 148 denotes a sub-filter applied to remove one of the signals modulated by the optical modulator when the same frequency shift value is generated in both positive and negative directions with respect to the second sub-divided signal.

제1광커플러(150)는 메인 광분할기(133)로부터 기준광섬유(135) 및 광변조부(145)를 거쳐 생성된 변조신호와 광서큘레이터(137)의 제1출력단(137c)을 통해 출력되는 신호를 커플링하여 출력한다.The first optical coupler 150 outputs the modulated signal generated from the main optical splitter 133 via the reference optical fiber 135 and the optical modulator 145 and the first output end 137c of the optical circulator 137 And outputs the coupled signal.

필터(160)는 제1광커플러(150)에서 출력되는 신호에 대해 브릴루앙 산란신호에 대응되게 설정된 대역의 신호를 필터링하여 출력한다.The filter 160 filters and outputs a signal output from the first optical coupler 150 in a band corresponding to the Brillouin scattering signal.

광검출기(170)는 필터(160)에서 출력되는 광에 대응되는 전기적 신호를 출력한다.The photodetector 170 outputs an electrical signal corresponding to the light output from the filter 160.

주파수 모니터링부(180)는 주파수 가변광원(120)에서 출력되는 광의 주파수를 모니터링하기 위해 적용된 것으로 서브광분할기(131)에서 분기된 모니터링용 광을 검출하여 측정부(190)에 출력한다.The frequency monitoring unit 180 is adapted to monitor the frequency of the light output from the frequency variable light source 120. The frequency monitoring unit 180 detects the monitoring light branched from the sub light splitter 131 and outputs the monitoring light to the measuring unit 190.

주파수 모니터링부(180)는 입사된 모니터링용 광을 분할하여 제1경로와 제1경로보다 경로가 길게 형성된 제2경로를 통해 진행시킨 후 다시 합파한 간섭광을 검출하여 출력하도록 구축될 수 있다.The frequency monitoring unit 180 may divide the incident monitoring light and proceed through a first path and a second path having a longer path than the first path, and detect and output the multiplexed interference light again.

주파수 모니터링부(180)를 통해 출력되는 신호는 측정부(190)의 주파수 선형화 동기 신호로 이용된다.The signal output through the frequency monitoring unit 180 is used as a frequency linearizing synchronization signal of the measuring unit 190.

측정부(190)는 광변조부(145)를 통해 출력되는 변조신호의 주파수를 조정하면서 광검출기(170)에서 출력되는 신호로부터 센싱광섬유(140)에 대해 측정하고자 하는 물리량 예를 들면, 온도 또는 스트레인을 산출한다.The measuring unit 190 measures a physical quantity to be measured for the sensing optical fiber 140 from a signal output from the photodetector 170 while adjusting the frequency of the modulation signal output through the optical modulating unit 145, Strain is calculated.

이러한 센서 시스템(100)은 광변조부(145)에 의해 브릴루앙 산란 주파수에 대응되는 주파수 신호로 변조하여 제1광커플러(150)에 제공하도록 되어 있어, 제1광커플러(150)에서는 수십MHz 대역으로 주파수가 쉬프트된 브릴루앙 산란신호를 취득할 수 있다.The sensor system 100 is modulated with a frequency signal corresponding to the Brillouin scattering frequency by the optical modulator 145 and is provided to the first optical coupler 150. In the first optical coupler 150, It is possible to obtain a Brillouin scattering signal whose frequency is shifted to the band.

일 예로서, 1550nm의 광을 1 내지 5THz/s 정도의 주파수 가변속도로 가변하면서 1km 이내의 길이로 설치된 센싱 광섬유(140)에 전송하는 경우 고유적으로 11GHz 정도에 해당하는 브릴루앙 산란신호가 발생되며, 센싱광섬유(140)에서 발생되는 브릴루앙 산란신호는 광변조부(145)에 의해 생성된 신호에 의해 기준광섬유(135)와 센싱광섬유(140)의 산란위치에 대응한 경로차이에 해당하는 주파수 변화량에 대응되게 수십Mhz 신호대역을 주파수가 낮아짐으로써 광검출기의 검출이 가능하다.For example, when a light of 1550 nm is transmitted to a sensing optical fiber 140 having a length of 1 km or less while varying a variable frequency of 1 to 5 THz / s, Brillouin scattering signal corresponding to 11 GHz is inherently generated The Brillouin scattering signal generated in the sensing optical fiber 140 is converted into a frequency corresponding to a path difference corresponding to the scattering position of the reference optical fiber 135 and the sensing optical fiber 140 by a signal generated by the optical modulator 145, Detection of the photodetector is possible by lowering the frequency of the signal band of several tens of MHz to correspond to the change amount.

이상에서 설명된 브릴루앙 산란기반 분포형 광섬유 센서 시스템에 의하면, 센싱광섬유로부터 산란된 브릴루앙 산란신호의 수신감도를 높여 측정할 수 있는 장점을 제공한다.According to the Brillouin scattering-based distributed optical fiber sensor system described above, the sensitivity to the Brillouin scattering signal scattered from the sensing optical fiber can be increased and the measurement sensitivity can be improved.

120: 주파수 가변 광원 133: 메인 광분할기
137: 광써큘레이터 140: 센싱광섬유
145: 광변조부 150: 제1광커플러
160: 필터 190: 측정부120: frequency variable light source 133: main light splitter
137: optical circulator 140: sensing optical fiber
145: optical modulator 150: first optical coupler
160: filter 190:

Claims (3)

1550nm의 광을 1 내지 5 THz/s 의 주파수 가변속도로 가변되는 광을 출사하는 주파수 가변 광원과;
상기 주파수 가변 광원에서 출력되는 신호를 측정용과 모니터링용으로 분할하여 출력하는 서브광분할기와;
상기 서브 광분할기에서 측정용으로 출력되는 신호를 제1분할신호와 제2분할신호로 분할하는 메인 광분할기와;
입력단을 통해 입력된 상기 제1분할신호를 센싱 광섬유에 출력하고, 상기 센싱 광섬유에서 반사된 광을 제1출력단을 통해 출력하는 광써큘레이터와;
상기 메인 광분할기에서 출력되는 제2분할신호를 전송하는 기준광섬유와;
상기 기준 광섬유 상에 결합되어 상기 제2분할신호를 변조한 변조신호를 생성하여 출력하는 광변조부와;
상기 메인 광분할기로부터 상기 기준광섬유 및 상기 광변조부를 경유하여 전송된 변조신호와 상기 제1출력단을 통해 출력되는 신호를 커플링하여 출력하는 제1광커플러와;
상기 제1광커플러에서 출력되는 신호에 대해 브릴루앙 산란신호에 대응되게 설정된 대역의 신호를 필터링하여 출력하는 필터와;
상기 필터를 거쳐 출력되는 신호를 검출하는 광검출부와;
상기 변조신호의 주파수가 가변되게 상기 광변조부를 제어하면서 상기 광검출부에서 출력되는 신호로부터 상기 센싱광섬유에 대해 측정하고자 하는 물리량을 산출하는 측정부와;
상기 광변조부와 상기 제1광커플러 사이에 마련되어 상기 광변조부에서 출력되는 신호와 상기 센싱광섬유의 종단을 통해 진행되는 광을 합파하여 상기 제1광커플러로 전송하는 제2광커플러와;
상기 주파수 가변 광원에서 출력되는 모니터링용 신호를 검출하여 상기 측정부에 출력하는 주파수 모니터링부;를 구비하고,
상기 광변조부는 상기 제2분할신호에 대해 11GHz 내지 12GHz 범위내에서 주파수를 변조하도록 되어 있는 것을 특징으로 하는 브릴루앙 산란기반 분포형 광섬유 센서 시스템.A frequency variable light source that emits light having a wavelength of 1550 nm at a variable frequency of 1 to 5 THz / s;
A sub-beam splitter for dividing a signal output from the frequency variable light source for measurement and monitoring;
A main beam splitter for dividing a signal output for measurement by the sub-optical sub-divider into a first sub-signal and a second sub-signal;
An optical circulator outputting the first divided signal inputted through an input terminal to a sensing optical fiber and outputting the light reflected from the sensing optical fiber through a first output terminal;
A reference optical fiber for transmitting a second split signal output from the main optical splitter;
An optical modulator coupled to the reference optical fiber for generating and outputting a modulated signal modulated with the second divided signal;
A first optical coupler coupling and outputting a modulation signal transmitted from the main optical splitter via the reference optical fiber and the optical modulator and a signal output through the first output terminal;
A filter for filtering a signal output from the first optical coupler in a band corresponding to the Brillouin scattering signal;
A photodetector for detecting a signal output through the filter;
A measuring unit for calculating a physical quantity to be measured with respect to the sensing optical fiber from a signal output from the optical detecting unit while controlling the optical modulating unit so that the frequency of the modulating signal varies;
A second optical coupler provided between the optical modulator and the first optical coupler to multiplex a signal output from the optical modulator and light traveling through an end of the sensing optical fiber and transmit the multiplexed signal to the first optical coupler;
And a frequency monitoring unit for detecting a monitoring signal output from the frequency variable light source and outputting the monitoring signal to the measurement unit,
Wherein the optical modulator is adapted to modulate a frequency within a range of 11 GHz to 12 GHz with respect to the second divided signal. 삭제delete 삭제delete
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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20220060307A (en) * 2020-11-04 2022-05-11 한국광기술원 OFDR system and measuring method thereof

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR102087686B1 (en) * 2017-12-06 2020-03-11 한국광기술원 railway crack detection apparatus
KR102087687B1 (en) * 2017-12-08 2020-03-11 한국광기술원 railway defomation detection apparatus
WO2020027393A1 (en) * 2018-07-30 2020-02-06 한국광기술원 Distributed optical fiber sensor device and method for controlling same
KR102163517B1 (en) * 2018-12-19 2020-10-07 한국광기술원 distributed optical fiber sensor apparatus and control method thereof
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KR20230061762A (en) * 2021-10-29 2023-05-09 한국광기술원 Distributed Acostic Sensor

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2000180265A (en) 1998-12-14 2000-06-30 Anritsu Corp Brillouin gain spectrum measuring method and device
JP2004101472A (en) * 2002-09-12 2004-04-02 Mitsubishi Heavy Ind Ltd Distortion temperature measurement system using optical fiber
KR101182650B1 (en) * 2010-10-19 2012-09-14 한국과학기술연구원 Distributed optical fiber sensor and sensing method using bbrillouin scattering
JP2014044129A (en) 2012-08-27 2014-03-13 Univ Of Tokyo Optical fiber characteristic measuring apparatus, and optical fiber characteristic measuring method

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2000180265A (en) 1998-12-14 2000-06-30 Anritsu Corp Brillouin gain spectrum measuring method and device
JP2004101472A (en) * 2002-09-12 2004-04-02 Mitsubishi Heavy Ind Ltd Distortion temperature measurement system using optical fiber
KR101182650B1 (en) * 2010-10-19 2012-09-14 한국과학기술연구원 Distributed optical fiber sensor and sensing method using bbrillouin scattering
JP2014044129A (en) 2012-08-27 2014-03-13 Univ Of Tokyo Optical fiber characteristic measuring apparatus, and optical fiber characteristic measuring method

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20220060307A (en) * 2020-11-04 2022-05-11 한국광기술원 OFDR system and measuring method thereof
KR102444123B1 (en) * 2020-11-04 2022-09-19 한국광기술원 OFDR system and measuring method thereof

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