WO2017117707A1 - 基于频率合成的光频域反射方法及系统 - Google Patents

基于频率合成的光频域反射方法及系统 Download PDF

Info

Publication number
WO2017117707A1
WO2017117707A1 PCT/CN2016/070108 CN2016070108W WO2017117707A1 WO 2017117707 A1 WO2017117707 A1 WO 2017117707A1 CN 2016070108 W CN2016070108 W CN 2016070108W WO 2017117707 A1 WO2017117707 A1 WO 2017117707A1
Authority
WO
WIPO (PCT)
Prior art keywords
optical
frequency
signal
electro
frequency domain
Prior art date
Application number
PCT/CN2016/070108
Other languages
English (en)
French (fr)
Inventor
何祖源
刘庆文
樊昕昱
陈典
Original Assignee
上海交通大学
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 上海交通大学 filed Critical 上海交通大学
Priority to JP2018532786A priority Critical patent/JP6698164B2/ja
Priority to PCT/CN2016/070108 priority patent/WO2017117707A1/zh
Priority to US16/066,119 priority patent/US10461850B2/en
Priority to EP16882854.9A priority patent/EP3386118B1/en
Publication of WO2017117707A1 publication Critical patent/WO2017117707A1/zh

Links

Images

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
    • H04B10/07—Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems
    • H04B10/071—Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems using a reflected signal, e.g. using optical time domain reflectometers [OTDR]
    • 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
    • G01D5/35306—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 an interferometer arrangement
    • 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
    • G01D5/35306—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 an interferometer arrangement
    • G01D5/35335—Aspects of emitters or receivers used by an interferometer in an optical fibre sensor arrangement
    • 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
    • G01D5/35361—Sensor working in reflection using backscattering to detect the measured quantity using elastic backscattering to detect the measured quantity, e.g. using Rayleigh backscattering

Definitions

  • the invention relates to a technology in the field of light sensing, in particular to an optical frequency domain reflectometer method and system based on frequency synthesis.
  • Optical fiber sensing technology refers to the technology of measuring physical signals (such as temperature and strain) or measuring various parameters of optical fibers by using optical waves as carriers and optical fibers as medium. Compared with traditional mechanical or electromagnetic sensors, optical fiber sensors have great advantages, such as noise generated by electromagnetic interference and stable operation under strong electromagnetic environment.
  • Optical fibers are electrical insulators that do not generate electric sparks and can be flammable. Working in hazardous locations such as explosives, fiber optic sensors can be combined with fiber-optic communication systems to achieve ultra-long-range sensing, and more.
  • Light reflectometer technology is an important member of the fiber optic sensing technology family. It is a technology for non-destructive detection of fiber optic networks using fiber backscattered light. It can measure the distribution of fiber length, loss, connectors, breaks, etc. happening.
  • one of the most important optical reflectometer technologies is an optical time domain reflectmeter (OTDR) technology using optical pulse detection.
  • OTDR optical time domain reflectmeter
  • the advantage of OTDR technology is that the fiber detection distance is very long, generally up to hundreds of kilometers; the system structure is simple and the cost is low, and there are commercial products on the market.
  • the spatial resolution of the OTDR technology (the minimum distance that can resolve two adjacent "event points") depends on the width of the light pulse, the narrower the light pulse, the higher the spatial resolution; and the optical pulse is limited by the laser performance and The nonlinear effect of the fiber can not be done very narrowly, so the spatial resolution of the OTDR technology is poor, which limits the application of the OTDR technology.
  • OFDR optical frequency domain reflectmeter
  • the tunable range of the source frequency is limited, and the spatial resolution is difficult to increase. It has been reported in the literature that a wide-bandwidth laser is modulated by a radio frequency sweep signal source and a single sideband modulator to obtain a wide range of linear swept source to achieve high spatial resolution [J. Lightwave Technol. 6, 3287-3294 (2008) )], this solution has become the mainstream choice for externally modulated OFDR systems.
  • the shortcomings of the single sideband modulator include complicated use, high price, large insertion loss, etc. Full suppression of other sidebands, single-sideband sweeping, which seriously affects the performance of the sweep, and the sweep range of this scheme is limited by the performance of the RF sweep source. Therefore, it is necessary to find a light reflectometer that achieves high spatial resolution and long detection distance.
  • Chinese Patent Document No. CN103763022A published on Japanese Patent No. 2014.4.30, discloses a high spatial resolution optical frequency domain reflectometer system based on high-order sideband swept modulation, including a swept source portion. And testing the optical path portion, the receiver and the signal processing portion, wherein the swept source portion uses a narrow linewidth laser as the original light source, and the emitted light is externally modulated to generate a swept sideband optical signal.
  • the frequency-swept RF signal is amplified by a high-power RF amplifier, and is applied to an electro-optic modulator with a low half-wave voltage at a high voltage to generate a multi-order sideband, which is filtered by a narrow-band optical filter to obtain a high-order.
  • the broadband sideband of the broadband sweep introduces the high-order sideband as a swept carrier light source into the optical path system, collects backscattered and reflected optical signals, and realizes optical frequency domain reflection analysis through local coherent detection and signal processing.
  • the hardware complexity of the technology is high, the filtering effect is limited by the performance of the filter, and the other sidebands cannot be completely suppressed, which seriously affects the frequency sweep performance; after the other sidebands are filtered, the optical power loss is extremely large, and a high magnification is required.
  • the optical amplifier is amplified to bring extra phase noise.
  • the invention aims at the above-mentioned deficiencies of the prior art, and proposes an optical frequency domain reflection method and system based on frequency synthesis, which uses an electro-optical modulator and an acousto-optic modulator to generate a multi-frequency simultaneous frequency-swept optical pulse signal, which breaks through the modulator performance.
  • the performance of the RF sweep signal source is limited, and the optical signal with good linearity, single frequency and wide sweep frequency range is obtained, and the spatial resolution and the detection distance are improved, and the hardware cost and software complexity of the system are not increased.
  • the invention relates to an optical frequency domain reflection method based on frequency synthesis.
  • the local light is modulated by electro-optical modulation and acousto-optic light to obtain an optical pulse, which is used as a detection pulse optical signal to be input into the test fiber, and the obtained Rayleigh backscattering is obtained.
  • the optical signal is coupled with the local light to perform photoelectric conversion and demodulation, thereby realizing optical frequency reflection, wherein: the electro-optic modulation is modulated by a single-frequency signal, the acousto-optic modulation is modulated by a pulse signal, and the optical comb is obtained by electro-optic modulation.
  • the plurality of frequency components of the signal are simultaneously swept to obtain a light pulse.
  • the local light is a narrow linewidth laser.
  • the pulse signal is a chirped pulse signal.
  • the frequency interval of the optical comb signal is equal to the sweep frequency range of the pulse signal.
  • the electro-optic modulation refers to modulating a high-frequency sinusoidal electrical signal into a single-frequency optical signal by intensity modulation or phase modulation to generate an optical frequency comb signal.
  • the acousto-optic modulation refers to: modulating an optical comb signal by a pulse signal to obtain a multi-frequency swept optical pulse signal.
  • the invention relates to an optical frequency domain reflection system based on frequency synthesis, comprising: a reference optical branch and a modulated optical branch, a coupling unit and a demodulation unit homologous thereto, wherein: the reference optical branch and the modulated optical branch The output ends are connected to the coupling unit, and the output end of the coupling unit is connected to the demodulation unit.
  • the input optical branch and the input end of the modulated optical branch receive a narrow linewidth laser from the same laser.
  • the laser passes through the fiber coupler to output a narrow linewidth laser to the modulation at a split ratio of 99:1.
  • Optical branch and reference optical branch are preferably, the laser passes through the fiber coupler to output a narrow linewidth laser to the modulation at a split ratio of 99:1.
  • the reference optical branch is provided with a polarization controller.
  • the modulated optical branch includes: an electro-optic modulator, an acousto-optic modulator, a doped fiber amplifier, an optical circulator, and a test fiber sequentially connected in series, wherein: the electro-optic modulator modulates the single-frequency signal to generate an optical comb signal, and inputs The optical comb signal of the acousto-optic modulator is modulated by a pulse signal to obtain a multi-frequency swept optical pulse signal, which is amplified by a doped fiber amplifier and output to an optical circulator and a test optical fiber.
  • the reflective end of the optical circulator acts as a modulated optical branch.
  • the output is connected to the coupling unit.
  • the electro-optic modulator is an electro-optic intensity modulator or an electro-optical phase modulator.
  • the coupling unit employs, but is not limited to, a 50:50 fiber coupler in which local light from the reference optical branch and Rayleigh backscattered light output from the fiber optic circulator are coupled in a 50:50 fiber coupler.
  • the demodulation unit comprises: a photoelectric conversion module, a data acquisition card and a demodulation module, wherein: the data acquisition card collects an electrical signal converted by the photoelectric conversion module, and is demodulated by the demodulation module.
  • the acousto-optic modulator can effectively suppress the laser phase noise and the influence of the environment on the optical phase, so that the maximum detection distance of the system breaks the coherence distance limitation, and the system hardware cost and software complexity are not increase;
  • the method of multi-frequency simultaneous frequency sweep and frequency synthesis in the digital domain can break the limitation of the maximum sweep range of the acousto-optic modulator and the RF sweep signal source, and multiply the spatial resolution of the system.
  • Figure 1 is a schematic view of the present invention
  • 2 is a schematic diagram of an optical spectrum of an optical pulse signal
  • Figure 3 is a signal diagram of the output of the embodiment
  • FC/APC connector is a comparison diagram of the reflection point of the FC/APC connector at 70 km of the test fiber before and after frequency synthesis
  • 1 is a narrow linewidth fiber laser
  • 2 is a fiber coupler
  • 3 is an electro-optic modulator
  • 4 is an acousto-optic modulator
  • 5 is a doped fiber amplifier
  • 6 is a DC voltage source
  • 7 is a two-channel arbitrary waveform.
  • 8 is fiber optic circulator
  • 9 is test fiber
  • 10 is DC bias voltage
  • 11 is single frequency sinusoidal signal
  • 12 is swept RF pulse signal
  • 13 is trigger and reference clock signal
  • 14 is polarization controller
  • 16 is a Rayleigh backscattered light signal
  • 17 is a 50:50 fiber coupler
  • 18 is a balanced detector
  • 19 is a data acquisition card
  • 20 is a computer.
  • the embodiment includes: a test fiber 9 , a signal generating module, a narrow linewidth laser light source module, a combing module, a frequency sweeping module, a coherent receiving module, a photoelectric conversion module, and a digital signal. a processing module, wherein: the coherent receiving module is connected to the test fiber 9
  • the signal generating module is a dual-channel arbitrary waveform generator 7, and the dual-channel arbitrary waveform generator 7 outputs the amplified single-frequency sinusoidal signal 11 and the frequency-swept RF pulse signal to the optical comb generating module and the sweeping and shearing pulse module respectively. 12, and send a trigger and reference clock signal to the digital signal processing module.
  • the single-frequency sinusoidal signal 11 has a frequency of 40 MHz and an initial phase of 0°.
  • the frequency of the swept RF pulse signal 12 is 180 MHz, the termination frequency is 220 MHz, the sweep duration is 8 ⁇ s, and the sweep frequency range is 40 MHz.
  • the test fiber 9 is a common single-mode fiber with a length of 75 km, without any isolation treatment, and is completely exposed to the laboratory environment.
  • the test fiber 9 is provided with FC/APC connectors at 25 km, 35 km, 45 km, and 70 km, respectively.
  • the swept RF pulse signal 12 is a frequency chirp signal.
  • the narrow linewidth laser light source module comprises: a narrow linewidth fiber laser 1 and a 99:1 fiber coupler 2 connected in sequence, wherein the ultra narrow linewidth laser generated by the narrow linewidth fiber laser 1 is coupled through a 99:1 fiber.
  • the device 2 is divided into 99% power of probe light and 1% power of local light.
  • the optical comb generating module comprises: a DC voltage source 6 and an electro-optic modulator 3, wherein: the DC voltage source 6 adjusts the DC bias voltage 10 of the input electro-optic modulator 3, so that the probe light and the single frequency input to the electro-optic modulator 3
  • the sinusoidal signal 11 produces an optical comb signal.
  • the electro-optic modulator 3 is an electro-optic intensity modulator or an electro-optic phase modulator, and the probe light outputs an optical comb signal having a plurality of frequency components through the electro-optic modulator 3.
  • the number of the frequency components depends on the modulation voltage and the setting of the DC bias voltage 10, and thus is variable, and the increase in the number is equivalent to increase the spatial resolution; in this embodiment, the frequency component is five, and the optical comb signal
  • the frequency interval is 40 MHz, and the intensity of each frequency component is substantially the same, and the frequency interval is strictly equal to the sweep frequency range of the swept RF pulse signal 12.
  • the swept cut pulse module includes: an acousto-optic modulator 4 and a doped fiber amplifier 5 connected in sequence, wherein: the optical comb signal input to the acousto-optic modulator 4 and the swept RF pulse signal 12 are simultaneously swept and cut.
  • a multi-frequency swept optical pulse signal is obtained and amplified by the doped fiber amplifier 5 for output.
  • the coherent receiving module comprises: a fiber optic circulator 8 connected in series, a test fiber 9 and a 50:50 fiber coupling 17, wherein: the multi-frequency swept optical pulse signal enters from the a port of the fiber circulator 8 and is measured from the b port incident test fiber 9, and the returned Rayleigh backscattered light signal 16 passes through the b port of the fiber circulator 8 Upon entering and exiting the c port, the local light output by the fiber coupler 2 and the Rayleigh backscattered light 16 output from the fiber circulator 8 are coupled in a 50:50 fiber coupler 17 to beat the beat.
  • the ultra-narrow linewidth laser generated by the narrow linewidth fiber laser 1 enters the splitting from the a port of the 99:1 fiber coupler 2, separates the probe light from the b port, and separates the local light from the c port.
  • the output of the fiber coupler 2 is preferably provided with a polarization controller 14.
  • the photoelectric conversion module described above is implemented by the balance detector 18 in this embodiment.
  • the digital signal processing module includes: a data acquisition card 19 and a calculation unit 20 connected in sequence, wherein the data collected by the data acquisition card 19 is synthesized and processed and analyzed in the calculation unit 20, namely:
  • the calculation unit 20 generates a digital frequency sweep signal (complex signal) having the same number of segments as the frequency component according to the original data obtained by the data acquisition card 19;
  • the frequency interval is ⁇ .
  • N 2; after the optical comb signal passes through the sweep-cutting pulse module, the two-frequency swept optical pulse signal is obtained, and the sweep rate is ⁇ , the sweep duration is ⁇ p , and the sweep range is 2 ⁇ p .
  • the Rayleigh scattered light at a certain point of the test fiber is received by the coherent receiving module, and the obtained original data can be expressed as:
  • A( ⁇ 0 ) is the reflection coefficient of the reflection point
  • ⁇ 0 is the round-trip time of the reflection point
  • ⁇ L is the laser center frequency
  • C is the laser phase noise and phase noise introduced by the environment
  • rect() is a rectangular window function.
  • a 5-segment digital frequency sweep signal (complex signal) is generated, and the sweep frequency ranges are: 100-140 MHz, 140-180 MHz, 180-220 MHz, 220-260 MHz, and 260-300 MHz, and the duration is 8 ⁇ s.
  • the generated complex signals are respectively multiplied by the window function, and cross-correlated with the original data collected by the data acquisition card 19 to obtain a corresponding correlation function ( Complex function).
  • the window function uses a Hanning window function, and in other cases, other types of window functions may be used.
  • the peak of the demodulated result after synthesis is narrower and higher, and the technical effect of improving the spatial resolution is achieved.
  • the single-segment sweep range is 40MHz, and the 5-segment sweep synthesis can be equivalent to a sweep range of 200MHz.
  • the first reflection point is the connection between the b port of the fiber circulator 8 and the test fiber 9.
  • the single-segment sweep frequency range is 40MHz, and the corresponding spatial resolution is 2.5m.
  • the theoretical spatial resolution should be 5m; after the 5-segment sweep synthesis, the equivalent sweep frequency range is 200MHz.
  • the corresponding spatial resolution is 0.5m.
  • the theoretical spatial resolution should be 1m.
  • the spatial resolution after synthesis can be measured to be 1.2 m, which is about 5 times higher than the spatial resolution of 5.8 m before synthesis, and the theory The analysis is highly consistent.
  • the local optical signal received by the 50:50 fiber coupler 17 is a non-swept optical signal with a constant frequency, which is distinguished from the local frequency of the conventional OFDR system frequency ⁇ .
  • the dual channel arbitrary waveform generator 7 outputs a trigger and reference clock signal to the data acquisition card 19 to fully synchronize the clocks of both.
  • the balance detector 18 performs photoelectric conversion.
  • the digital signal is synthesized into an equivalent large swept range signal in the computing unit 20 to achieve high spatial resolution optical frequency domain reflection analysis.
  • the probe light is sequentially formed by the electro-optic modulator 3 and the acousto-optic modulator 4 to form multi-frequency and simultaneously-swept pulsed light, which is different from the single-frequency swept frequency and constant optical power of the conventional OFDR system.
  • the acousto-optic modulator 4 replaces a conventional single sideband modulator to sweep a narrow linewidth laser to obtain a better single Sideband sweeping effect, and no other sideband interference, simple to use, reduced insertion loss, and more stable performance.
  • the acousto-optic modulator 4 pulsing the detected optical signal which can effectively suppress the influence of the laser phase noise and the environment on the optical phase, so that the maximum detection distance of the embodiment breaks the coherence distance limitation and does not increase the system hardware cost and Software complexity.
  • the method of multi-frequency simultaneous frequency sweep and frequency synthesis in the digital domain can break the limitation of the maximum sweep range of the acousto-optic modulator 4 and the RF sweep signal source, and multiply the spatial resolution of the system.
  • the multi-frequency simultaneous frequency-scanning digital synthesis OFDR can multiply the spatial resolution by a factor of two, and the multiplier is equal to the number of frequencies, which breaks the limitation of the acousto-optic modulator sweep range; on the other hand,
  • the 70km of the test fiber 9 has exceeded the coherence length of the light source, but the spatial resolution still coincides with the theoretical resolution, indicating that the phase noise has little effect on the system.
  • This embodiment effectively suppresses the phase noise effect. If the power of the probe light is increased, the fiber of a longer distance can be detected; similarly, increasing the number of frequency components of the comb signal can improve the spatial resolution.

Abstract

一种基于频率合成的光频域反射方法及系统，通过将本地光经电光调制(3)和声光调制(4)后得到光脉冲，将其作为探测脉冲光信号(15)输入测试光纤(9)，将得到的瑞利背向散射光信号(16)与本地光耦合拍频后进行光电转换并解调，从而实现光频率反射计，其中：电光调制(3)采用单频信号(11)进行调制，声光调制(4)采用脉冲信号(12)进行调制，并将电光调制(3)得到的光梳信号的多个频率成分同时扫频，从而得到光脉冲；该光频域反射方法及系统探测距离大、空间分辨率高，并且硬件成本和软件复杂度低。

Description

基于频率合成的光频域反射方法及系统 技术领域
本发明涉及的是一种光传感领域的技术，具体是一种基于频率合成的光频域反射计方法及系统。
背景技术
自20世纪70年代以来，光纤通信技术凭借其超大传输带宽、超低传输损耗等诸多优势得到了迅猛发展。与光纤通信技术同时期飞速发展的还有光纤传感技术。光纤传感技术是指以光波为载体，以光纤为媒介，对外界物理信号(如温度和应变)或者对光纤各参数测量的技术。相比于传统的机械式或电磁式传感器，光纤传感器有着巨大的优势，比如不受电磁干扰产生噪声、可以在强电磁环境下稳定地工作，光纤是电绝缘体不产生电火花，可以在易燃易爆等危险场所工作，光纤传感器可以与光纤通信系统完美结合，实现超远距离的传感，等等。
光反射计技术是光纤传感技术家族中的重要成员，它是一种利用光纤背向散射光对光纤网络进行无损探测的一种技术，可以测量光纤长度、损耗、连接器、断裂等的分布情况。目前最主要的一种光反射计技术是采用光脉冲探测的光时域反射计(Optical Time Domain Reflectmeter,OTDR)技术。OTDR技术的优势在于光纤探测距离很长，一般可达上百公里；系统结构简单，成本低廉，目前市面上已有商用产品。但由于OTDR技术的空间分辨率(能够分辨两个相邻”事件点”的最小距离)取决于光脉冲的宽度，光脉冲越窄，空间分辨率越高；而光脉冲受限于激光器性能和光纤非线性效应而无法做的很窄，因此OTDR技术的空间分辨率差，这点限制了OTDR技术的应用。
为了解决空间分辨率的问题，研究人员提出光频率域反射计(Optical Frequency Domain Reflectmeter,OFDR)技术。OFDR技术的空间分辨率取决于光源频率可调谐范围，只要光源频率可调谐范围越大，理论空间分辨率越高。但OFDR技术也面临两个主要问题。其一，OFDR技术的探测距离较短，最大探测距离一般不超过激光器相干距离的一半。有文献报道利用辅助干涉仪进行相位噪声补偿以提高探测距离[Opt.Lett.32(22),3227–3229(2007)]，但这种技术的硬件复杂度高，相位噪声补偿算法复杂导致处理数据时间长，且无法补偿环境因素引入的相位噪声。其二，光源频率可调谐范围有限，空间分辨率很难再提高。有文献报道利用射频扫频信号源和单边带调制器对窄线宽激光器进行调制，得到大范围的线性扫频光源，实现高空间分辨率[J.Lightwave Technol.6,3287-3294(2008)]，这种方案现已成为外部调制的OFDR系统的主流选择。但是单边带调制器的缺点包括使用复杂、价格昂贵、插入损耗大等，更严重的是无法完 全抑制其他边带，实现单边带扫频，这严重影响了扫频的性能，而且这种方案的扫频范围受限于射频扫频信号源的性能。因此寻找实现高空间分辨率和长探测距离的光反射计十分必要。
经过对现有技术的检索发现，中国专利文献号CN103763022A，公开日2014.4.30，公开了一种基于高阶边带扫频调制的高空间分辨率光频域反射计系统，包括扫频光源部分、测试光路部分、接收机及信号处理部分，所述的扫频光源部分使用窄线宽激光器作为原始光源，出射光经过外部调制产生扫频的边带光信号。所述的外部调制过程中，扫频射频信号通过高功率射频放大器放大，以高电压加载到半波电压较低的电光调制器，产生多阶的边带，通过窄带光学滤波器滤波得到高阶的宽带扫频的光边带将高阶边带作为扫频载波光源导入光路系统，采集背向散射和反射的光信号，通过本地的相干检测和信号处理，实现光频域反射分析。但该技术硬件复杂度高，滤波效果受限于滤波器的性能，无法完全抑制其他边带，严重影响了扫频性能；其余边带滤除后，光功率损耗极大，需使用高倍率的光放大器放大，带来额外的相位噪声。
发明内容
本发明针对现有技术存在的上述不足，提出一种基于频率合成的光频域反射方法及系统，采用电光调制器和声光调制器产生多频率同时扫频的光脉冲信号，突破调制器性能和射频扫频信号源性能的限制，获得线性度佳、频率单一、扫频范围大的光信号，提高空间分辨率和探测距离，不增加系统的硬件成本和软件复杂度。
本发明是通过以下技术方案实现的：
本发明涉及一种基于频率合成的光频域反射方法，通过将本地光经电光调制和声光调制后得到光脉冲，将其作为探测脉冲光信号输入测试光纤，将得到的瑞利背向散射光信号与本地光耦合拍频后进行光电转换并解调，从而实现光频率反射，其中：电光调制采用单频信号进行调制，声光调制采用脉冲信号进行调制，并将电光调制得到的光梳信号的多个频率成分同时扫频，从而得到光脉冲。
所述的本地光为窄线宽激光。
所述的脉冲信号为啁啾脉冲信号。
所述的光梳信号的频率间隔等于脉冲信号的扫频范围。
所述的电光调制是指：将高频正弦电信号以强度调制或相位调制方式调制到单频光信号上，产生光频率梳信号。
所述的声光调制是指：通过脉冲信号对光梳信号进行调制，得到多频率扫频光脉冲信号。
本发明涉及一种基于频率合成的光频域反射系统，包括：参考光支路和与之同源的调制光支路、耦合单元以及解调单元，其中：参考光支路和调制光支路的输出端均与耦合单元相连，耦合单元的输出端与解调单元相连。
所述的参考光支路和调制光支路的输入端接收来自同一激光器的窄线宽激光，优选为该激光器经过光纤耦合器，将窄线宽激光以99:1的分光比分别输出至调制光支路和参考光支路。
所述的参考光支路上优选设有偏振控制器。
所述的调制光支路包括：依次串联的电光调制器、声光调制器、掺饵光纤放大器、光环行器和测试光纤，其中：电光调制器通过单频信号进行调制产生光梳信号，输入声光调制器的光梳信号经脉冲信号调制得到多频率扫频光脉冲信号，并经掺饵光纤放大器放大后输出至光环行器和测试光纤，光环行器的反射端作为调制光支路的输出与耦合单元相连。
所述的电光调制器为电光强度调制器或电光相位调制器。
所述的耦合单元采用但不限于50：50光纤耦合器，其中：来自参考光支路的本地光和光纤环形器输出的瑞利背向散射光在50：50光纤耦合器中耦合拍频。
所述的解调单元包括：光电转换模块、数据采集卡和解调模块，其中：数据采集卡采集经过光电转换模块转换后的电信号，由解调模块进行解调。
技术效果
与现有技术相比，本发明技术效果包括：
1)采用声光调制器对窄线宽激光扫频，可获得更好的单边带扫频效果，没有其他边带的干扰；并具备更低的插入损耗，使用简单，性能更稳定；
2)声光调制器对探测光切脉冲，可以有效地抑制激光相位噪声和环境对光相位的影响，使得本系统的最大探测距离突破了相干距离限制，并且系统硬件成本和软件复杂度并未增加；
3)采用多频率同时扫频并在数字域进行频率合成的方法，可以突破声光调制器和射频扫频信号源的最大扫频范围的限制，成倍地提高系统的空间分辨率。
附图说明
图1为本发明示意图；
图2为光脉冲信号的光频谱示意图；
图3为实施例输出的信号曲线图；
图4为实施例在测试光纤70km处FC/APC连接头的反射点在频率合成前后对比图；
图中：1为窄线宽光纤激光器，2为光纤耦合器，3为电光调制器，4为声光调制器，5为掺饵光纤放大器，6为直流电压源，7为双通道任意波形发生器，8为光纤环形器，9为测试光纤，10为直流偏置电压，11为单频正弦信号，12为扫频射频脉冲信号，13为触发和参考时钟信号，14为偏振控制器，15为探测脉冲光信号，16为瑞利背向散射光信号，17为50：50光纤耦合器，18为平衡探测器，19为数据采集卡，20为计算机。
具体实施方式
下面对本发明的实施例作详细说明，本实施例在以本发明技术方案为前提下进行实施，给出了详细的实施方式和具体的操作过程，但本发明的保护范围不限于下述的实施例。
实施例1
如图1所示，本实施例包括：测试光纤9、信号发生模块、依次相连的窄线宽激光光源模块、光梳生成模块、扫频切脉冲模块、相干接收模块、光电转换模块和数字信号处理模块，其中：相干接收模块与测试光纤9相连，
所述的信号发生模块为双通道任意波形发生器7，该双通道任意波形发生器7向光梳生成模块和扫频切脉冲模块分别输出放大后的单频正弦信号11和扫频射频脉冲信号12，并且向数字信号处理模块发送触发和参考时钟信号。
所述的单频正弦信号11频率为40MHz，初始相位为0°。
所述的扫频射频脉冲信号12的初始频率为180MHz，终止频率为220MHz，扫频持续时间为8μs，扫频范围为40MHz。
所述的测试光纤9为普通单模光纤，长度为75km，未做任何隔离处理，完全暴露在实验室环境中。
所述的测试光纤9在25km、35km、45km和70km处分别设置有FC/APC连接头。
所述的扫频射频脉冲信号12为频率啁啾脉冲信号。
所述的窄线宽激光光源模块包括：依次相连的窄线宽光纤激光器1和99：1光纤耦合器2，其中：窄线宽光纤激光器1产生的超窄线宽激光经过99：1光纤耦合器2分为99％功率的探测光和1％功率的本地光。
所述的光梳生成模块包括：直流电压源6和电光调制器3，其中：直流电压源6调整输入电光调制器3的直流偏置电压10，使输入电光调制器3的探测光和单频正弦信号11产生光梳信号。
所述的电光调制器3为电光强度调制器或电光相位调制器，所述的探测光经过电光调制器3输出有若干频率分量的光梳信号。
所述的频率分量的数量取决于调制电压及直流偏置电压10的设置，因而是可变的，且数量的增加等效提高空间分辨率；本实施例中频率分量为5个，光梳信号频率间隔为40MHz，并且各频率成分的强度基本相同、频率间隔严格等于扫频射频脉冲信号12的扫频范围。
所述的扫频切脉冲模块包括：依次相连的声光调制器4和掺饵光纤放大器5，其中：输入声光调制器4的光梳信号和扫频射频脉冲信号12同时扫频切脉冲，得到多频率扫频光脉冲信号，并经掺饵光纤放大器5放大后输出。
所述的相干接收模块包括：依次相连的光纤环形器8、测试光纤9和50：50光纤耦合 器17，其中：多频率扫频光脉冲信号从光纤环形器8的a端口进入并从b端口入射测试光纤9进行测量，返回的瑞利背向散射光信号16通过光纤环形器8的b端口进入并从c端口出射，光纤耦合器2输出的本地光和光纤环形器8输出的瑞利背向散射光16在50：50光纤耦合器17中耦合拍频。
所述的窄线宽光纤激光器1产生的超窄线宽激光从99：1光纤耦合器2的a端口进入分束，从b端口分出探测光，从c端口分出本地光。
所述的光纤耦合器2的输出端优选设有偏振控制器14。
所述的光电转换模块在本实施例中通过平衡探测器18实现。
所述的数字信号处理模块包括：依次相连的数据采集卡19和计算单元20，其中：数据采集卡19采集到的数据在计算单元20中进行合成和处理分析，即：
1)计算单元20根据数据采集卡19得到的原始数据，产生与其频率分量数量相同段数的数字扫频信号(复信号)；
当电光调制器3输出的光梳信号有N个频率分量，频率间隔为Ω。为简化分析，令N＝2；光梳信号经过扫频切脉冲模块后，得到两频率的扫频光脉冲信号，其扫频速率皆为γ，扫频持续时间为τp，扫频范围为2πγτp。测试光纤某一点的瑞利散射光经相干接收模块接收，得到的原始数据可表示为：
Figure PCTCN2016070108-appb-000001
其中：A(τ0)为该反射点的反射系数，τ0为该反射点往返时间，ωL为激光器中心频率，C为激光器相位噪声和由环境引入的相位噪声，rect()为矩形窗函数。虽然上述两个频率的拍频信号同时进入数据采集模块，因为其频率范围不同，所以在数据处理中利用滤波器可以将其准确分离。
所述的对应的数字扫频信号的表达式为：
Figure PCTCN2016070108-appb-000002
本实施例产生5段数字扫频信号(复信号)，其扫频范围分别为：100～140MHz、140～180MHz、180～220MHz、220～260MHz和260～300MHz，持续时间均为8μs。
2)为消除解调结果中反射点的旁瓣的影响，将产生的复信号分别与窗函数相乘，并与数据采集卡19采集到的原始数据做互相关运算，得到对应的相关函数(复函数)。
本实施例中上述窗函数采用Hanning窗函数，在其他场合下也可以采用其他类型的窗函数实现。
所述的相关函数的表达式为：
Figure PCTCN2016070108-appb-000003
3)将得到的复函数直接相加取模，得到数字扫频信号合成的解调结果。
当且仅当Ω＝2πγτp，即光梳信号的频率间隔严格等于扫频射频脉冲信号的扫频范围时，将得到的两个复函数直接相加取模，得到多段数字扫频信号合成的解调结果如下式所示：
Figure PCTCN2016070108-appb-000004
相比于合成之前的解调结果，合成后的解调结果的峰更窄更高，达到了提高空间分辨率的技术效果。
如图2所示，单段扫频范围为40MHz，5段扫频合成后可以等效为200MHz的扫频范围。
如图3所示，可清晰地看出有6个反射点，第一个反射点为光纤环形器8的b端口与测试光纤9的连接头。根据理论分析，单段扫频范围为40MHz，对应的空间分辨率为2.5m，加窗函数解调后，理论空间分辨率应为5m；5段扫频合成后等效扫频范围为200MHz，对应的空间分辨率为0.5m，加窗函数解调后，理论空间分辨率应为1m。
如图4所示，在测试光纤9的70km处反射点，可以测量出合成后的空间分辨率为1.2m，与合成前的5.8m的空间分辨率相比，提升了约5倍，与理论分析高度吻合。
所述的50：50光纤耦合器17接收的本地光信号为频率恒定不变的非扫频光信号，区别为传统的OFDR系统频率啁啾的本地光。
所述的双通道任意波形发生器7向数据采集卡19输出触发和参考时钟信号以使二者的时钟完全同步。
所述的平衡探测器18进行光电转换。
所述的数字信号在计算单元20中被合成为一个等效的大扫频范围信号，实现高空间分辨率的光频域反射分析。
所述的探测光依次经过电光调制器3和声光调制器4形成多频率同时扫频的脉冲光，区别于传统OFDR系统的单频率扫频、恒定光功率的探测光。
所述的声光调制器4取代传统的单边带调制器对窄线宽激光进行扫频，可获得更好的单 边带扫频效果，并且没有其他边带的干扰，使用简单，插入损耗降低，性能更稳定。
所述的声光调制器4对探测光信号切脉冲，可有效抑制激光相位噪声和环境对光相位的影响，使本实施例的最大探测距离突破了相干距离限制，并且未增加系统硬件成本和软件复杂度。
本实施例采用多频率同时扫频并在数字域进行频率合成的方法，可以突破声光调制器4和射频扫频信号源的最大扫频范围的限制，成倍地提高系统的空间分辨率。
本实施例的结果表明，一方面多频率同时扫频的数字合成OFDR能够成倍地提升空间分辨率，提升倍数等于频率的数量，突破了声光调制器扫频范围的限制；另一方面，测试光纤9的70km处已经超过了光源的相干长度，但空间分辨率仍然与理论分辨率相吻合，说明相位噪声对该系统的影响很小，本实施例有效地抑制了相位噪声影响。如果增大探测光功率，便可以探测更长距离的光纤；同样地，增加光梳信号的频率成分数量，可以提高空间分辨率。

Claims (13)

  1. 一种基于频率合成的光频域反射方法，其特征在于，通过将本地光经电光调制和声光调制后得到光脉冲，将其作为探测脉冲光信号输入测试光纤，将得到的瑞利背向散射光信号与本地光耦合拍频后进行光电转换并解调，从而实现光频率反射计，其中：电光调制采用单频信号进行调制，声光调制采用脉冲信号进行调制，并将电光调制得到的光梳信号的多个频率成分同时扫频，从而得到光脉冲。
  2. 根据权利要求1所述的基于频率合成的光频域反射方法，其特征是，所述的本地光为窄线宽激光；所述的脉冲信号为啁啾脉冲信号。
  3. 根据权利要求1所述的基于频率合成的光频域反射方法，其特征是，所述的光梳信号的频率间隔等于脉冲信号的扫频范围。
  4. 根据权利要求1所述的基于频率合成的光频域反射方法，其特征是，所述的电光调制是指：将高频正弦电信号以强度调制或相位调制方式调制到单频光信号上，产生光频率梳信号。
  5. 根据权利要求1所述的基于频率合成的光频域反射方法，其特征是，所述的声光调制是指：通过脉冲信号对光梳信号进行调制，得到多频率扫频光脉冲信号。
  6. 根据权利要求1所述的基于频率合成的光频域反射方法，其特征是，所述的解调是指：根据光电转换后得到的电信号，产生与其频率分量数量相同段数的数字扫频信号；将产生的多段复信号分别与窗函数相乘，并分别与原始数据做互相关运算，得到相应的相关函数；将得到的多个复函数直接相加取模，得到多段数字扫频信号合成的解调结果。
  7. 根据权利要求6所述的基于频率合成的光频域反射方法，其特征是，所述的窗函数为Hanning窗函数。
  8. 一种基于频率合成的光频域反射系统，其特征在于，包括：参考光支路和与之同源的调制光支路、耦合单元以及解调单元，其中：参考光支路和调制光支路的输出端均与耦合单元相连，耦合单元的输出端与解调单元相连；
    所述的调制光支路包括：依次串联的电光调制器、声光调制器、掺饵光纤放大器、光环行 器和测试光纤，其中：电光调制器通过单频信号进行调制产生光梳信号，输入声光调制器的光梳信号经脉冲信号调制得到多频率扫频光脉冲信号，并经掺饵光纤放大器放大后依次输出至光环行器和测试光纤，光环行器的反射端作为调制光支路的输出与耦合单元相连。
  9. 根据权利要求8所述的光频域反射系统，其特征是，所述的参考光支路和调制光支路的输入端接收来自同一激光器的窄线宽激光，该激光器经过光纤耦合器，将窄线宽激光以99:1的分光比分别输出至调制光支路和参考光支路。
  10. 根据权利要求8所述的光频域反射系统，其特征是，所述的参考光支路上设有偏振控制器。
  11. 根据权利要求8所述的光频域反射系统，其特征是，所述的电光调制器为电光强度调制器或电光相位调制器。
  12. 根据权利要求8所述的光频域反射系统，其特征是，所述的耦合单元采用50：50光纤耦合器，其中：来自参考光支路的本地光和光纤环形器输出的瑞利背向散射光在50：50光纤耦合器中耦合拍频。
  13. 根据权利要求8所述的光频域反射系统，其特征是，所述的解调单元包括：光电转换模块、数据采集卡和解调模块，其中：数据采集卡采集经过光电转换模块转换后的电信号，由解调模块进行解调。
PCT/CN2016/070108 2016-01-05 2016-01-05 基于频率合成的光频域反射方法及系统 WO2017117707A1 (zh)

Priority Applications (4)

Application Number Priority Date Filing Date Title
JP2018532786A JP6698164B2 (ja) 2016-01-05 2016-01-05 周波数合成に基づいた光周波数領域反射方法及びシステム
PCT/CN2016/070108 WO2017117707A1 (zh) 2016-01-05 2016-01-05 基于频率合成的光频域反射方法及系统
US16/066,119 US10461850B2 (en) 2016-01-05 2016-01-05 Frequency synthesis-based optical frequency domain reflectometry method and system
EP16882854.9A EP3386118B1 (en) 2016-01-05 2016-01-05 Frequency synthesis-based optical frequency domain reflectometry method and system

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/CN2016/070108 WO2017117707A1 (zh) 2016-01-05 2016-01-05 基于频率合成的光频域反射方法及系统

Publications (1)

Publication Number Publication Date
WO2017117707A1 true WO2017117707A1 (zh) 2017-07-13

Family

ID=59273313

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2016/070108 WO2017117707A1 (zh) 2016-01-05 2016-01-05 基于频率合成的光频域反射方法及系统

Country Status (4)

Country Link
US (1) US10461850B2 (zh)
EP (1) EP3386118B1 (zh)
JP (1) JP6698164B2 (zh)
WO (1) WO2017117707A1 (zh)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111157097A (zh) * 2019-12-31 2020-05-15 太原理工大学 一种基于相位敏感光时域反射系统的振动信号检测方法
CN112363146A (zh) * 2020-11-13 2021-02-12 杭州爱莱达科技有限公司 双调制共光路线性调频连续波测距测速方法及装置
CN117073990A (zh) * 2023-10-16 2023-11-17 常州灵动芯光科技有限公司 一种窄线宽激光器的线宽测试系统及测试方法

Families Citing this family (20)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2016069744A1 (en) 2014-10-29 2016-05-06 Bridger Photonics, Inc. Accurate chirped synthetic wavelength interferometer
US9970756B2 (en) 2015-10-06 2018-05-15 Bridger Photonics, Inc. High-sensitivity gas-mapping 3D imager and method of operation
WO2019079448A1 (en) 2017-10-17 2019-04-25 Bridger Photonics, Inc. ROTARY OPTICAL REFLECTOR APPARATUSES AND METHODS
WO2019099567A1 (en) 2017-11-14 2019-05-23 Bridger Photonics, Inc. Apparatuses and methods for anomalous gas concentration detection
CN109981198B (zh) * 2019-04-10 2020-05-01 北京邮电大学 一种基于多模光纤的宽带射频谱感知方法及系统
CN110285333A (zh) * 2019-07-12 2019-09-27 上海交通大学 基于光纤的油气管道泄漏监测系统
CN113517922B (zh) * 2020-04-09 2022-09-02 华为技术有限公司 一种信号检测方法和光时域反射仪
CN111721732B (zh) * 2020-06-03 2023-05-12 华东师范大学 基于多光梳系统测量气体红外多维光谱的装置及工作方法
CN111998933B (zh) * 2020-08-10 2023-01-24 武汉理工大学 一种基于脉冲编码的光纤光栅振动测量装置及方法
CN112327319B (zh) * 2020-11-09 2023-12-19 之江实验室 基于循环移频环的固态激光雷达探测方法及系统
CN112697181B (zh) * 2020-12-02 2022-07-26 广东工业大学 一种基于频率调制的相位敏感光时域反射装置及方法
US11221274B1 (en) * 2020-12-09 2022-01-11 Peking University Light scattering parameter measurement system and its measurement method
CN112902861B (zh) * 2021-01-26 2022-08-02 哈尔滨工程大学 一种基于超大测量范围pdh传感的应变测量装置
CN113340571B (zh) * 2021-05-29 2023-11-10 南京航空航天大学 基于光矢量分析的光时延测量方法及装置
US11942986B2 (en) * 2021-09-24 2024-03-26 Viavi Solutions Inc. Optical time-domain reflectometer (OTDR) including channel checker
CN113688807B (zh) * 2021-10-26 2022-02-08 中科慧远视觉技术(北京)有限公司 一种自适应缺陷检测方法、装置、识别系统及存储介质
CN114280549B (zh) * 2021-12-26 2024-02-27 中国电子科技集团公司第十四研究所 一种高速光脉冲产生装置及方法
CN114323589A (zh) * 2021-12-30 2022-04-12 苏州六幺四信息科技有限责任公司 一种基于光双边带调制的光器件频响快速测量方法及装置
US20240063913A1 (en) * 2022-08-16 2024-02-22 GenXComm, Inc. Phase stable signal generator and signal distribution system
CN117029999B (zh) * 2023-10-09 2024-01-30 山东省科学院激光研究所 基于脉冲调制技术的分布式声波传感系统及测量方法

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6475932A (en) * 1987-09-17 1989-03-22 Yokogawa Electric Corp Optical fiber testing apparatus
CN103763022A (zh) * 2013-12-06 2014-04-30 何祖源 一种基于高阶边带扫频调制的高空间分辨率光频域反射计系统
CN103984184A (zh) * 2014-05-19 2014-08-13 上海交通大学 光脉冲压缩反射装置
CN105067103A (zh) * 2015-08-31 2015-11-18 上海交通大学 基于光频域反射计的振动检测装置及其方法
CN105490738A (zh) * 2016-01-05 2016-04-13 上海交通大学 基于频率合成的光频域反射方法及系统
CN205453695U (zh) * 2016-01-05 2016-08-10 上海交通大学 基于频率合成的光频域反射装置

Family Cites Families (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2002090259A (ja) 2000-09-19 2002-03-27 Anritsu Corp 半導体レーザ光源装置及び光周波数領域反射測定装置
US7414779B2 (en) * 2005-01-20 2008-08-19 Massachusetts Institute Of Technology Mode locking methods and apparatus
CA2569764A1 (en) * 2005-12-01 2007-06-01 Bing Li Method, system and apparatus for optical phase modulation based on frequency shift
JP5256225B2 (ja) 2010-01-29 2013-08-07 日本電信電話株式会社 光線路測定装置及び光線路測定方法
JP2011174760A (ja) 2010-02-23 2011-09-08 Nippon Telegr & Teleph Corp <Ntt> 光周波数領域反射測定方法及び光周波数領域反射測定装置
JP5561679B2 (ja) 2011-06-27 2014-07-30 日本電信電話株式会社 光周波数領域反射測定方法及び光周波数領域反射測定装置
CN102322880B (zh) * 2011-08-18 2013-06-05 天津大学 偏振敏感的分布式光频域反射扰动传感装置和解调方法
WO2015170355A1 (en) * 2014-05-05 2015-11-12 Filippo Bastianini Apparatus for interrogating distributed optical fibre sensors using a stimulated brillouin scattering optical frequency-domain interferometer
WO2016033192A1 (en) * 2014-08-28 2016-03-03 Adelos, Inc. Noise management for optical time delay interferometry
US9500562B2 (en) * 2015-02-05 2016-11-22 University Of Ottawa Kerr phase-interrogator for sensing and signal processing applications
WO2016138291A1 (en) * 2015-02-26 2016-09-01 California Institute Of Technology Optical frequency divider based on an electro-optical-modulator frequency comb

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6475932A (en) * 1987-09-17 1989-03-22 Yokogawa Electric Corp Optical fiber testing apparatus
CN103763022A (zh) * 2013-12-06 2014-04-30 何祖源 一种基于高阶边带扫频调制的高空间分辨率光频域反射计系统
CN103984184A (zh) * 2014-05-19 2014-08-13 上海交通大学 光脉冲压缩反射装置
CN105067103A (zh) * 2015-08-31 2015-11-18 上海交通大学 基于光频域反射计的振动检测装置及其方法
CN105490738A (zh) * 2016-01-05 2016-04-13 上海交通大学 基于频率合成的光频域反射方法及系统
CN205453695U (zh) * 2016-01-05 2016-08-10 上海交通大学 基于频率合成的光频域反射装置

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111157097A (zh) * 2019-12-31 2020-05-15 太原理工大学 一种基于相位敏感光时域反射系统的振动信号检测方法
CN112363146A (zh) * 2020-11-13 2021-02-12 杭州爱莱达科技有限公司 双调制共光路线性调频连续波测距测速方法及装置
CN117073990A (zh) * 2023-10-16 2023-11-17 常州灵动芯光科技有限公司 一种窄线宽激光器的线宽测试系统及测试方法
CN117073990B (zh) * 2023-10-16 2024-01-26 常州灵动芯光科技有限公司 一种窄线宽激光器的线宽测试系统及测试方法

Also Published As

Publication number Publication date
JP6698164B2 (ja) 2020-05-27
EP3386118A4 (en) 2019-08-14
JP2019507327A (ja) 2019-03-14
EP3386118A1 (en) 2018-10-10
US20190013862A1 (en) 2019-01-10
US10461850B2 (en) 2019-10-29
EP3386118B1 (en) 2021-02-24

Similar Documents

Publication Publication Date Title
WO2017117707A1 (zh) 基于频率合成的光频域反射方法及系统
CN105490738B (zh) 基于频率合成的光频域反射方法及系统
EP3483572B1 (en) Distributed fibre sensing system and vibration detection and positioning method therefor
CN111238551B (zh) 分布式相位敏感光时域反射仪传感系统及相位提取方法
CN110160572A (zh) 基于艾赫兹超快脉冲扫描的高性能分布式光纤传感系统
CN110108346B (zh) 基于延迟调相啁啾脉冲对的光纤振动传感器
CN110220470B (zh) 基于瑞利散射的单端混沌布里渊动态应变测量装置及方法
WO2015176362A1 (zh) 光脉冲压缩反射装置
CN110470376B (zh) 一种干涉分布式光纤声传感装置及其传感方法
CN114563025A (zh) 光学感测的方法及装置
GB2558961A (en) Method and system for differentiating macro-bend losses from splice and connector losses in fiber-optic links
CN205453695U (zh) 基于频率合成的光频域反射装置
CN113315573A (zh) 一种光学辅助的宽带微波瞬时频率测量方法和装置
CN115876350A (zh) 一种基于光频梳的快速布里渊光学相关域分析仪
CN103674082A (zh) 一种基于四波混频过程的高空间分辨率光频域反射计系统
CN203642943U (zh) 一种基于四波混频过程的高空间分辨率光频域反射计系统
CN111637910B (zh) 时域差分高速混沌布里渊光相干域监测装置及方法
CN111307188B (zh) 一种基于噪声调制的免扫频botda装置
CN111141414B (zh) 基于混沌bocda的温度与应变同时测量装置及方法
CN110375960A (zh) 一种基于超连续谱光源otdr的装置及方法
CN115839762A (zh) 基于ofdr原理的双脉冲长距离分布式振动检测装置及检测方法
CN115452018A (zh) 一种基于脉冲自相干的光时域反射装置及方法
CN111721438B (zh) 一种噪声调制线阵ccd采集的免扫频botda装置
CN114353685A (zh) 基于混沌布里渊相位谱的高频动态应变测量装置和方法
CN113595638B (zh) 一种基于四分频驱动的botda系统

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 16882854

Country of ref document: EP

Kind code of ref document: A1

ENP Entry into the national phase

Ref document number: 2018532786

Country of ref document: JP

Kind code of ref document: A

WWE Wipo information: entry into national phase

Ref document number: 2016882854

Country of ref document: EP

NENP Non-entry into the national phase

Ref country code: DE

ENP Entry into the national phase

Ref document number: 2016882854

Country of ref document: EP

Effective date: 20180705