CN113390441A - Refractive index change sensing device and measuring method - Google Patents

Refractive index change sensing device and measuring method Download PDF

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CN113390441A
CN113390441A CN202110609462.3A CN202110609462A CN113390441A CN 113390441 A CN113390441 A CN 113390441A CN 202110609462 A CN202110609462 A CN 202110609462A CN 113390441 A CN113390441 A CN 113390441A
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refractive index
frequency
optical
external physical
signal
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CN113390441B (en
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邹新海
杜森阳
李越豪
冀涵颖
王恒
刘磊
黎人溥
郭俊启
刘宇
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Chongqing University of Post and Telecommunications
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    • 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
    • G01D5/268—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 using optical fibres
    • 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
    • G01D5/35329—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 using interferometer with two arms in transmission, e.g. Mach-Zender interferometer

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Abstract

The invention relates to a refractive index change sensing device and a measuring method, belonging to the field of optical fiber sensing, wherein the device comprises: the device comprises a laser, a carrier suppression double-sideband modulation module, a microwave source, an optical beam splitter, a refractive index sensitive module, a frequency shifter, an optical coupler, a photoelectric detector and a signal acquisition and data processing module. The laser, the carrier-suppression double-sideband modulation module, the optical beam splitter, the refractive index sensitive module, the frequency shifter, the optical coupler and the photoelectric detector are sequentially connected in an optical mode; the carrier-restraining double-sideband modulation module and the microwave source are sequentially connected in a circuit; and the photoelectric detector and the signal acquisition and data processing module are sequentially connected by a circuit. The invention overcomes the defects of low spectrum analysis precision in the existing optical fiber sensing detection technology and the need of a wide-frequency range detection and processing system in the traditional microwave photon sensing detection, and has the advantages of high measurement precision, real-time measurement, only need of a low-frequency detection and processing system and the like.

Description

Refractive index change sensing device and measuring method
Technical Field
The invention belongs to the optical fiber sensing technology, and particularly relates to a device and a measuring method based on refractive index change sensing.
Background
The optical fiber sensing technology is the research focus of the research field of the optical fiber technology since the optical fiber technology goes from theory to practice, and the requirements for the sensor are higher and higher along with the continuous development of the scientific technology. The sensitivity, the high accuracy, small become the sensor development direction. The traditional sensor can not meet the requirement gradually due to the defects of electromagnetic interference, high temperature and high voltage resistance and the like, and the optical fiber sensor can be widely applied due to the advantages of electromagnetic interference resistance, low loss, high cost performance, safety and the like. The basic principle of the optical fiber sensing technology is that when light is transmitted in an optical fiber, a physical parameter to be measured (such as temperature, pressure, stress, a magnetic field, an electric field and the like) changes characteristic parameters (such as frequency, phase, wavelength and the like) of the light transmitted in the optical fiber, so that optical properties (such as wavelength, phase, polarization state and the like) of the light in the optical fiber are changed, and the light with the changed optical properties becomes modulated light. And subsequently, the photoelectric detector is connected to the designed link output end through an optical fiber sensor demodulation technology, and the required external physical parameter is demodulated through the output signal of the photoelectric detector.
The simplest and most direct demodulation technology is a demodulation method of a spectrum analyzer, and the principle of the demodulation technology is that the phase change amount of modulated light is directly detected through spectral analysis of the modulated light by the spectrum analyzer, and then the change of an external physical parameter is calculated. Although the method is simple, the spectral analysis accuracy by directly utilizing the spectrometer is not high, and the method is inconvenient to integrate with other systems due to large volume and high price, and is only suitable for occasions such as laboratories and the like. For this purpose, a microwave photon sensing detection technique has been proposed in which an optical signal is converted into an electrical signal by a photodetector and digital signal processing is performed. The basic link consists of five parts, namely a light source, a modulator, a photon processing module, a photoelectric detector and a data processing module. The principle is that light emitted by a light source is sent into a modulator through an optical fiber, so that an external physical parameter and the light emitted by the light source interact in the modulator, and the optical property of the light is changed, namely modulated light. The modulated light enters a photon processing module and the physical parameters are processed in the optical domain. Then the optical signal output by the photon processing module is converted into an electric signal through the photoelectric detector and is sent to the data processing module for digital signal processing. But this detection technique requires the use of a broadband photodetector and processing system.
Disclosure of Invention
The present invention is directed to solving the above problems of the prior art. A refractive index change sensing device and a measuring method are provided. The technical scheme of the invention is as follows:
a refractive index change sensing device, comprising: a laser (1), a carrier suppression double-sideband modulation module (2), a microwave source (3), an optical beam splitter (4), a refractive index sensitive module (5), a frequency shifter (6), an optical coupler (7), a photoelectric detector (8) and a signal acquisition and data processing module (9),
the laser (1), the carrier-suppression double-sideband modulation module (2), the optical beam splitter (4), the refractive index sensitive module (5), the frequency shifter (6), the optical coupler (7) and the photoelectric detector (8) are sequentially optically connected; the carrier suppression double-sideband modulation module (2) and the microwave source (3) are sequentially connected in a circuit; the photoelectric detector (8) and the signal acquisition and data processing module (9) are sequentially connected by a circuit, wherein the output frequency of the laser (1) is f0The light wave enters a carrier-restraining double-sideband modulation module (2), and a microwave source (3) emits light with the frequency f1The microwave signal is loaded on the light wave through a carrier-restraining double-sideband modulation module (2) to generate a frequency f0-f1And f0+f1After the carrier-suppressed double-sideband optical signal output by the carrier-suppressed double-sideband modulation module (2) passes through the optical beam splitter (4)Is divided into two identical branches, namely a branch 1 and a branch 2; in the branch 1, the optical signal for inhibiting the carrier double-sideband passes through the refractive index sensitive module (5), the refractive index sensitive module (5) is used for sensing the refractive index change caused by the change of an external physical parameter, so that the phase difference of the two optical sidebands is changed, and in the branch 2, the optical signal for inhibiting the carrier double-sideband passes through the frequency shifter (6) to generate the frequency fsIs shifted so that the frequency is f0-f1And f0+f1Respectively of optical signals f0+f1+fsAnd f0-f1+fsOptical signals output by the two branches are coupled by an optical coupler (7) and then enter a photoelectric detector (8) to carry out heterodyne detection to output electric signals; the electric signal output by the photoelectric detector (8) is acquired by a signal acquisition and data processing module (9) and is subjected to data processing and analysis to obtain the frequency fsThe signal power p (m).
Furthermore, the carrier double-sideband modulation restraining module (2) can restrain the generation of carrier double-sideband modulation by working at the lowest bias point through a Mach-Zehnder modulator or can restrain the generation of carrier double-sideband modulation by filtering out a central carrier through the combination of an electro-optical modulator and an optical band-stop filter.
Furthermore, the refractive index sensitive module (5) comprises all modules, the refractive index of which can be changed due to the change of external physical parameters to be measured (such as temperature, pressure, stress, magnetic field, electric field, concentration, vibration and the like), and the refractive index change amounts of different light waves are different.
Further, the frequency shift amount f generated by the frequency shifter (6)sIn MHz magnitude, only a photoelectric detection and signal processing system with low frequency bandwidth is needed.
Further, changing external physical parameters to obtain the frequency fsPower function P (M) of signal power P (M) changing with external physical parameter M to be measuredwithComprises the following steps:
Figure BDA0003095038530000031
wherein R is the responsivity of the photodetector; a. the1And A2The optical signal amplitude values of the branch 1 and the branch 2 are respectively; j. the design is a square1(m) is a class of Bessel functions; m is the modulation coefficient of a modulator in the carrier suppression double-sideband modulation module;
Figure BDA0003095038530000032
is the initial phase difference of branch 1 and branch 2; f. ofsIs the frequency shift amount of the frequency shifter; d (M) is refractive index variation caused by an external physical parameter; lambda [ alpha ]0The wavelength of laser emitted by the laser; f. of1The frequency of the microwave signal emitted by the microwave source; c is the speed of the light wave in vacuum; t is a time parameter.
A refractive index change sensing measurement method based on the device, comprising the steps of:
1) the output frequency of the laser (1) is f0The light wave enters a carrier-restraining double-sideband modulation module (2), and a microwave source (3) emits light with the frequency f1The microwave signal is loaded on the light wave through a carrier-restraining double-sideband modulation module (2) to generate a frequency f0-f1And f0+f1After the optical signal for inhibiting the carrier double-sideband output by the module (2) for inhibiting the carrier double-sideband modulation passes through the optical beam splitter (4), the optical signal for inhibiting the carrier double-sideband is divided into two identical branches, namely a branch 1 and a branch 2;
2) in the branch 1, the optical signal for inhibiting the carrier double-sideband passes through the refractive index sensitive module (5), the refractive index sensitive module (5) is used for sensing the refractive index change caused by the change of an external physical parameter, so that the phase difference of the two optical sidebands is changed, and in the branch 2, the optical signal for inhibiting the carrier double-sideband passes through the frequency shifter (6) to generate the frequency fsIs shifted so that the frequency is f0-f1And f0+f1Respectively of optical signals f0+f1+fsAnd f0-f1+fsOptical signals output by the two branches are coupled by an optical coupler (7) and then enter a photoelectric detector (8) to carry out heterodyne detection to output electric signals;
3) the electric signal output by the photoelectric detector (8) is collected by a signal collecting and data processing module (9) and is analyzed by data processing,obtaining a frequency of fsThe signal power P (M) is changed to obtain the frequency fsPower function P (M) of signal power P (M) changing with external physical parameter M to be measuredwith；
4) And the other conditions are kept unchanged, and the frequency f of the microwave signal emitted by the microwave source (3) is set1If it is zero, repeating the above steps 1-3 to obtain a new frequency fsPower function P (M) of signal power P (M) changing with external physical parameter M to be measuredwithout；
5) Constructing a transmission function (ACF) F (M) which is changed along with the external physical parameter M by the ratio of the power functions obtained twicewithout/P(M)withAnd then measuring the ACF value corresponding to the external physical parameter to be measured, and comparing the operation result with the prestored ACF curve parameter to obtain the size of the external physical parameter.
Further, changing the external physical parameter to obtain the frequency fsPower function P (M) of signal power P (M) changing with external physical parameter M to be measuredwithThe method specifically comprises the following steps:
power function P (M)withComprises the following steps:
Figure BDA0003095038530000041
wherein R is the responsivity of the photodetector; a. the1And A2The optical signal amplitude values of the branch 1 and the branch 2 are respectively; j. the design is a square1(m) is a class of Bessel functions; m is the modulation coefficient of a modulator in the carrier suppression double-sideband modulation module;
Figure BDA0003095038530000042
is the initial phase difference of branch 1 and branch 2; f. ofsIs the frequency shift amount of the frequency shifter; d (M) is the refractive index variation caused by the external physical parameter. Lambda [ alpha ]0The wavelength of laser emitted by the laser; f. of1The frequency of the microwave signal emitted by the microwave source; c is the speed of the light wave in vacuum; t is a time parameter.
Further, said step 4) The method specifically comprises the following steps: the frequency f of the microwave signal emitted by the microwave source (3) is set under the condition that other conditions are kept unchanged1Zero, repeating the above steps 1) -3) to obtain a new frequency fsPower function P (M) of signal power P (M) changing with external physical parameter M to be measuredwithoutComprises the following steps:
Figure BDA0003095038530000043
constructing a transmission function ACF which changes along with the external physical parameter M to be measured according to the ratio of the power functions obtained twice as follows:
Figure BDA0003095038530000044
only the ACF value corresponding to the external physical parameter to be measured needs to be measured, and the operation result is compared with the pre-stored ACF curve parameter, so that the size of the external physical parameter to be measured is obtained.
The invention has the following advantages and beneficial effects:
the invention relates to a device and a measuring method based on refractive index change sensing, which can realize the measurement of a power attenuation transmission function generated by a large-range external physical parameter through a refractive index sensitive module by adopting a frequency shifter for inhibiting carrier double-sideband modulation signals from respectively passing through the refractive index sensitive module and a tiny frequency shift amount and detecting heterodyne beat frequency of a refractive index change optical signal and a frequency shift optical signal only by detecting a fixed low-frequency component signal, thereby greatly reducing the detection requirement of microwave photon sensing detection.
The invention adopts a frequency shift heterodyne structure, can effectively overcome the problems of frequency drift and jitter of the laser, and realizes high-precision and wide-range external physical parameter measurement by constructing a transmission function. And by varying the microwave signal f emitted by the microwave source1And external physical parameter mapping function curves with different precisions and ranges can be constructed.
Drawings
FIG. 1 is a schematic diagram of the structure of a device for sensing based on refractive index change according to a preferred embodiment of the present invention.
In the figure: 1-laser; 2-a carrier-suppressed double sideband modulation module; 3-a microwave source; 4-an optical beam splitter; 5-a refractive index sensitive module; 6-a frequency shifter; 7-an optical coupler; 8-a photodetector; and 9, a signal acquisition and data processing module.
FIG. 2 is a graph of refractive index variation versus microwave power variation obtained by the present invention.
Detailed Description
The technical solutions in the embodiments of the present invention will be described in detail and clearly with reference to the accompanying drawings. The described embodiments are only some of the embodiments of the present invention.
The technical scheme for solving the technical problems is as follows:
the invention provides a sensing device based on refractive index change, which comprises: the device comprises a laser 1, a carrier suppression double-sideband modulation module 2, a microwave source 3, an optical beam splitter 4, a refractive index sensitive module 5, a frequency shifter 6, an optical coupler 7, a photoelectric detector 8 and a signal acquisition and data processing module 9.
The working principle of the sensing device and the measuring method based on the refractive index change is as follows:
the laser 1 has an output frequency f0The light wave enters a carrier-restraining double-sideband modulation module 2, and a microwave source 3 emits light with the frequency f1The microwave signal is loaded on the light wave through the carrier-restraining double-sideband modulation module 2 to generate a frequency f0-f1And f0+f1The carrier-suppressed double-sideband optical signal output by the carrier-suppressed double-sideband modulation module 2 is divided into two identical branches after passing through the optical beam splitter 4, namely a branch 1 and a branch 2; in the branch 1, the optical signal for inhibiting the carrier double-sideband passes through the refractive index sensitive module 5, the refractive index sensitive module 5 is used for sensing the refractive index change caused by the change of the external physical parameter, so that the phase difference of the two optical sidebands is changed, and in the branch 2, the optical signal for inhibiting the carrier double-sideband passes through the frequency shifter 6 to generate the frequency fsIs movedFrequency, so that the frequency is f0-f1And f0+f1Respectively of optical signals f0+f1+fsAnd f0-f1+fsOptical signals output by the two branches are coupled by an optical coupler 7 and enter a photoelectric detector 8 to carry out heterodyne detection to output electric signals; the electric signal output by the photoelectric detector 8 is acquired by the signal acquisition and data processing module 9 and is processed and analyzed to obtain the frequency fsThe signal power p (m). Changing the external physical parameter to obtain the frequency fsPower function P (M) of signal power P (M) changing with external physical parameter M)withComprises the following steps:
Figure BDA0003095038530000061
wherein R is the responsivity of the photodetector; a. the1And A2The optical signal amplitude values of the branch 1 and the branch 2 are respectively; j. the design is a square1(m) is a class of Bessel functions; m is the modulation coefficient of a modulator in the carrier suppression double-sideband modulation module;
Figure BDA0003095038530000062
is the initial phase difference of branch 1 and branch 2; f. ofsIs the frequency shift amount of the frequency shifter; d (M) is the refractive index variation caused by the external physical parameter.
The frequency f of the microwave signal emitted by the microwave source 3 is set to be constant under other conditions1If it is zero, repeating the above steps 1-3 to obtain a new acquisition frequency fsPower function P (M) of signal power P (M) changing with external physical parameter M)withoutComprises the following steps:
Figure BDA0003095038530000063
constructing a transmission function ACF which changes along with the external physical parameter M according to the ratio of the power functions obtained twice as follows:
Figure BDA0003095038530000071
only the ACF value corresponding to the external physical parameter to be measured needs to be measured, and the operation result is compared with the pre-stored ACF curve parameter, so that the size of the external physical parameter to be measured is obtained.
Examples
FIG. 1 is a schematic diagram of a refractive index change-based sensing device according to the present invention. The optical carrier output by the laser 1 is input into the carrier-restraining double-sideband modulation module 2, the microwave signal emitted by the microwave source 3 is loaded on the optical carrier through the carrier-restraining double-sideband modulation module 2, and the modulated optical carrier output by the carrier-restraining double-sideband modulation module 2 is divided into a branch 1 and a branch 2 through the optical beam splitter 4. In the branch 1, the optical signal of the carrier double sideband is restrained from passing through the refractive index sensitive module 5, and the refractive index sensitive module 5 is used for sensing the refractive index change caused by the change of the external physical parameter, so that the phase difference of the two optical sidebands is changed. In branch 2, the optical signal of the double-sideband with suppressed carrier is generated by a frequency shifter 6 with frequency fsThe frequency shift of (3). The optical signals output by the branch 1 and the branch 2 are coupled by the optical coupler 7 and enter the photoelectric detector 8 for photoelectric conversion. The electric signal output by the photoelectric detector 8 is processed and analyzed by the data acquisition and processing module 9. According to the invention, the frequency of a microwave signal emitted by a microwave source is set to be 16GHz, the FBG grating (the initial refractive index is 1.45) is selected as the refractive index sensitive module, the length is set to be 3mm, the frequency shift amount is set to be 0.1GHz by the frequency shifter, and a relation curve of the microwave power variation and the refractive index variation is obtained through the output of the signal acquisition and data processing module 8, as shown in FIG. 2. The acquired data is fitted to obtain a linear variation curve, whereby as a mapping function, when the power variation is 0.25dB, the corresponding refractive index variation is 0.002. Namely, the function curve constructed by the device based on refractive index change sensing of the invention really accords with a formula under the condition of inhibiting the carrier double-sideband modulation.
It should also be noted that the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.
The above examples are to be construed as merely illustrative and not limitative of the remainder of the disclosure. After reading the description of the invention, the skilled person can make various changes or modifications to the invention, and these equivalent changes and modifications also fall into the scope of the invention defined by the claims.

Claims (9)

1.一种折射率变化传感的装置，其特征在于，包括：激光器(1)、抑制载波双边带调制模块(2)、微波源(3)、光分束器(4)、折射率敏感模块(5)、移频器(6)、光耦合器(7)、光电探测器(8)及信号采集与数据处理模块(9)，1. A device for refractive index change sensing, comprising: a laser (1), a carrier suppression double sideband modulation module (2), a microwave source (3), an optical beam splitter (4), a refractive index sensitive a module (5), a frequency shifter (6), an optical coupler (7), a photodetector (8) and a signal acquisition and data processing module (9), 所述激光器(1)、抑制载波双边带调制模块(2)、光分束器(4)、折射率敏感模块(5)、移频器(6)、光耦合器(7)、光电探测器(8)依次光连接；所述抑制载波双边带调制模块(2)、微波源(3)依次电路连接；所述光电探测器(8)、信号采集与数据处理模块(9)依次电路连接，其中激光器(1)输出频率为f0的光波进入到抑制载波双边带调制模块(2)，微波源(3)发出频率为f1的微波信号通过抑制载波双边带调制模块(2)加载到光波上，产生频率为f0-f1和f0+f1的抑制载波双边带光信号，抑制载波双边带调制模块(2)输出的抑制载波双边带光信号通过光分束器(4)之后被分为完全相同的两条支路，分别为支路1和支路2；在支路1中，抑制载波双边带光信号通过折射率敏感模块(5)，利用折射率敏感模块(5)来敏感外界物理参量改变所造成的折射率变化，使两个光边带相位差发生改变，在支路2中，抑制载波双边带光信号通过移频器(6)产生频率为fs的移频，使得频率为f0-f1和f0+f1的光信号分别为f0+f1+fs和f0-f1+fs，两支路输出的光信号通过光耦合器(7)耦合后进入光电探测器(8)外差探测输出电信号；光电探测器(8)输出的电信号经信号采集与数据处理模块(9)采集和数据处理分析后，获得频率为fs处信号功率P(M)。The laser (1), a suppressed carrier double sideband modulation module (2), an optical beam splitter (4), a refractive index sensitive module (5), a frequency shifter (6), an optical coupler (7), and a photodetector (8) optical connection in sequence; the suppression carrier double sideband modulation module (2) and the microwave source (3) are connected in sequence by circuit; the photodetector (8), signal acquisition and data processing module (9) are connected by circuit in sequence, The laser (1) outputs a light wave with frequency f 0 and enters the suppressed carrier double sideband modulation module (2), and the microwave source (3) sends out a microwave signal with a frequency f 1 and is loaded into the light wave through the suppressed carrier double sideband modulation module (2). On the above, the suppressed carrier double sideband optical signals with frequencies f 0 -f 1 and f 0 +f 1 are generated, and the suppressed carrier double sideband optical signal output by the suppressed carrier double sideband modulation module (2) passes through the optical beam splitter (4). It is divided into two identical branches, namely branch 1 and branch 2; in branch 1, the carrier-suppressed double-sideband optical signal passes through the refractive index sensitive module (5), and uses the refractive index sensitive module (5) To be sensitive to the change of refractive index caused by the change of external physical parameters, the phase difference between the two optical sidebands will change. frequency, so that the optical signals with frequencies f 0 -f 1 and f 0 +f 1 are f 0 +f 1 +f s and f 0 -f 1 +f s respectively, and the optical signals output by the two branches pass through the optical coupler (7) After coupling, it enters into the photoelectric detector (8) for heterodyne detection and outputs the electrical signal; after the electrical signal output by the photoelectric detector (8) is collected and analyzed by the signal acquisition and data processing module (9), the obtained frequency is f Signal power P(M) at s . 2.根据权利要求1所述的一种折射率变化传感的装置，其特征在于，所述抑制载波双边带调制模块(2)通过马赫曾德尔调制器工作于最低偏置点实现抑制载波双边带调制产生或通过电光调制器与光带阻滤波器组合滤除中心载波产生。2. a kind of refractive index change sensing device according to claim 1, is characterized in that, described suppressing carrier double sideband modulation module (2) realizes suppressing carrier double sideband by working in the lowest bias point by Mach-Zehnder modulator Band modulation is generated or generated by combining an electro-optic modulator with an optical band-stop filter to filter out the center carrier. 3.根据权利要求1所述的一种折射率变化传感的装置，其特征在于，所述折射率敏感模块(5)包括所有能因外界待测物理参量改变而造成折射率发生改变的模块，外界待测物理参量包括温度、压力、应力、磁场、电场、浓度、振动，同时不同光波折射率改变量不同。3. The device for sensing a refractive index change according to claim 1, wherein the refractive index sensitive module (5) includes all modules that can cause the refractive index to change due to changes in external physical parameters to be measured. , the external physical parameters to be measured include temperature, pressure, stress, magnetic field, electric field, concentration, vibration, and the amount of change in the refractive index of different light waves is different. 4.根据权利要求3所述的一种折射率变化传感的装置，其特征在于，移频器(6)产生的频移量fs为MHz量级，只需低频带宽的光电探测及信号处理系统即可。4. a kind of refractive index change sensing device according to claim 3, is characterized in that, the frequency shift amount f s that frequency shifter (6) produces is MHz order, only needs the photoelectric detection and signal of low frequency bandwidth Process the system. 5.根据权利要求4所述的一种折射率变化传感的装置，其特征在于，改变外界物理参量，获得频率为fs处信号功率P(M)随外界待测物理参量M变化的功率函数P(M)with为：5. a kind of refractive index change sensing device according to claim 4, is characterized in that, changing external physical parameter, obtaining frequency is the power that the signal power P (M) at f s place changes with external physical parameter M to be measured The function P(M) with is:
Figure FDA0003095038520000021
Figure FDA0003095038520000021
 其中，其中R为光电探测器的响应度；A1和A2分别为支路1和支路2光信号幅度值；J1(m)为一类贝塞尔函数；m为抑制载波双边带调制模块中调制器的调制系数；
Figure FDA0003095038520000022
为支路1和支路2的初始相位差；fs为移频器的频移量；D(M)为外界物理参量引起的折射率变化量；λ0为激光器激射激光的波长；f1为微波源发出的微波信号频率；c为光波在真空中的速度；t为时间参量。Among them, R is the responsivity of the photodetector; A 1 and A 2 are the amplitudes of the optical signals of branch 1 and branch 2 respectively; J 1 (m) is a kind of Bessel function; m is the suppressed carrier double sideband The modulation coefficient of the modulator in the modulation module;
Figure FDA0003095038520000022
is the initial phase difference between branch 1 and branch 2; f s is the frequency shift of the frequency shifter; D(M) is the refractive index change caused by external physical parameters; λ 0 is the wavelength of the lasing laser; f 1 is the frequency of the microwave signal emitted by the microwave source; c is the speed of the light wave in vacuum; t is the time parameter. 6.一种基于权利要求1-5任一项所述装置的折射率变化传感测量方法，其特征在于，包括以下步骤：6. A refractive index change sensing measurement method based on the device of any one of claims 1-5, characterized in that, comprising the following steps: 1)、激光器(1)输出频率为f0的光波进入到抑制载波双边带调制模块(2)，微波源(3)发出频率为f1的微波信号通过抑制载波双边带调制模块(2)加载到光波上，产生频率为f0-f1和f0+f1的抑制载波双边带光信号，抑制载波双边带调制模块(2)输出的抑制载波双边带光信号通过光分束器(4)之后被分为完全相同的两条支路，分别为支路1和支路2；1), the laser (1) outputs the light wave with frequency f 0 into the suppression carrier double sideband modulation module (2), and the microwave source (3) sends out a microwave signal with frequency f 1 through the suppression carrier double sideband modulation module (2) to load On the light wave, a suppressed carrier double sideband optical signal with frequencies f 0 -f 1 and f 0 +f 1 is generated, and the suppressed carrier double sideband optical signal output by the suppressed carrier double sideband modulation module (2) passes through the optical beam splitter (4). ) is then divided into two identical branches, namely branch 1 and branch 2; 2)、在支路1中，抑制载波双边带光信号通过折射率敏感模块(5)，利用折射率敏感模块(5)来敏感外界物理参量改变所造成的折射率变化，使两个光边带相位差发生改变，在支路2中，抑制载波双边带光信号通过移频器(6)产生频率为fs的移频，使得频率为f0-f1和f0+f1的光信号分别为f0+f1+fs和f0-f1+fs，两支路输出的光信号通过光耦合器(7)耦合后进入光电探测器(8)外差探测输出电信号；2) In branch 1, the double-sideband optical signal of the suppressed carrier passes through the refractive index sensitive module (5), and the refractive index sensitive module (5) is used to sense the refractive index change caused by the change of external physical parameters, so that the two optical edges The band phase difference is changed. In branch 2, the suppressed carrier double-sideband optical signal passes through the frequency shifter (6) to generate a frequency shift of f s , so that the light with frequencies f 0 -f 1 and f 0 +f 1 The signals are f 0 +f 1 +f s and f 0 -f 1 +f s respectively. The optical signals output by the two branches are coupled by the optical coupler (7) and then enter the photodetector (8) for heterodyne detection and output electrical signals ; 3)、光电探测器(8)输出的电信号经信号采集与数据处理模块(9)采集和数据处理分析后，获得频率为fs处信号功率P(M)，改变外界物理参量获得频率为fs处信号功率P(M)随外界待测物理参量M变化的功率函数P(M)with；3) After the electrical signal output by the photodetector (8) is collected, processed and analyzed by the signal acquisition and data processing module (9), the signal power P(M) at the frequency f s is obtained, and the frequency obtained by changing the external physical parameters is The power function P(M) with that the signal power P(M) at f s changes with the external physical parameter M to be measured; 4)、其他条件保持不变，设置微波源(3)发出的微波信号频率f1为零，重复上述步骤1-3)得到新的频率为fs处信号功率P(M)随外界待测物理参量M变化的功率函数P(M)without；4), other conditions remain unchanged, set the frequency f 1 of the microwave signal sent by the microwave source (3) to zero, repeat the above steps 1-3) to obtain a new signal power P (M) at the frequency f s to be measured with the outside world. The power function P(M) without the variation of the physical parameter M; 5)、将两次获得的功率函数的比值构建随外界物理参量M变化的传输函数(ACF)F(M)＝P(M)without/P(M)with，后续只需测量出外界待测物理参量所对应的ACF值，运算结果与所预存的ACF曲线参数比较进而得到外界物理参量的大小。5), construct the transfer function (ACF) F(M)=P(M) without /P(M) with the ratio of the power function obtained twice with the change of the external physical parameter M, and then only need to measure the external to be measured The ACF value corresponding to the physical parameter, the operation result is compared with the pre-stored ACF curve parameter to obtain the size of the external physical parameter. 7.根据权利要求6所述的折射率变化传感的测量方法，其特征在于，改变外界物理参量获得频率为fs处信号功率P(M)随外界待测物理参量M变化的功率函数P(M)with，具体包括：7. the measuring method of refractive index change sensing according to claim 6, is characterized in that, changing external physical parameter to obtain frequency is the power function P that signal power P (M) at f s place changes with external physical parameter M to be measured (M) with , including: 功率函数P(M)with为：The power function P(M) with is:
Figure FDA0003095038520000031
Figure FDA0003095038520000031
 其中，其中R为光电探测器的响应度；A1和A2分别为支路1和支路2光信号幅度值；J1(m)为一类贝塞尔函数；m为抑制载波双边带调制模块中调制器的调制系数；
Figure FDA0003095038520000032
为支路1和支路2的初始相位差；fs为移频器的频移量；D(M)为外界物理参量引起的折射率变化量。λ0为激光器激射激光的波长；f1为微波源发出的微波信号频率；c为光波在真空中的速度；t为时间参量。Among them, R is the responsivity of the photodetector; A 1 and A 2 are the amplitudes of the optical signals of branch 1 and branch 2 respectively; J 1 (m) is a kind of Bessel function; m is the suppressed carrier double sideband The modulation coefficient of the modulator in the modulation module;
Figure FDA0003095038520000032
is the initial phase difference between branch 1 and branch 2; f s is the frequency shift of the frequency shifter; D(M) is the refractive index change caused by external physical parameters. λ 0 is the lasing wavelength of the laser; f 1 is the frequency of the microwave signal emitted by the microwave source; c is the speed of the light wave in vacuum; t is the time parameter. 8.根据权利要求6所述的折射率变化传感的测量方法，其特征在于，所述步骤4)具体为：其他条件保持不变，设置微波源(3)发出的微波信号频率f1为零，重复上述步骤1)-3)得到新的频率为fs处信号功率P(M)随外界待测物理参量M变化的功率函数P(M)without为：8. The method for measuring refractive index change sensing according to claim 6, wherein the step 4) is specifically: other conditions remain unchanged, and the frequency f of the microwave signal sent by the microwave source ( 3 ) is set to be 0, repeating the above steps 1)-3) to obtain a new frequency, the power function P(M) without which the signal power P(M) changes with the external physical parameter M to be measured at f s is:
Figure FDA0003095038520000033
Figure FDA0003095038520000033
 将两次获得的功率函数的比值构建随外界待测物理参量M变化的传输函数ACF为：The ratio of the power functions obtained twice to construct the transfer function ACF that changes with the external physical parameter M to be measured is:
Figure FDA0003095038520000041
Figure FDA0003095038520000041
 只需测量出外界待测物理参量所对应的ACF值，运算结果与所预存的ACF曲线参数比较，进而得到外界待测物理参量的大小。It is only necessary to measure the ACF value corresponding to the external physical parameter to be measured, and then compare the operation result with the pre-stored ACF curve parameters to obtain the size of the external physical parameter to be measured. 9.根据权利要求6所述基于折射率变化传感的测量方法，其特征在于，所述外界物理参量改变而造成折射率发生改变的模块，外界物理参量包括温度、压力、应力、磁场、电场、浓度、振动，同时不同光波折射率改变量不同。9. The measurement method based on refractive index change sensing according to claim 6, characterized in that, the module in which the refractive index is changed due to the change of the external physical parameters, the external physical parameters include temperature, pressure, stress, magnetic field, electric field , concentration, vibration, and the amount of change in the refractive index of different light waves is different.
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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114918529A (en) * 2022-05-30 2022-08-19 武汉荣科激光自动化设备有限公司 Light energy focusing control method and device for laser processing

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5532857A (en) * 1994-09-07 1996-07-02 Ael Industries, Inc. Wide dynamic range optical link using DSSC linearizer
CN102759371A (en) * 2012-07-19 2012-10-31 南京大学 COTDR (coherent detection based optical time-domain reflectometry) fused long-distance coherent detection brilouin optical time-domain analyzer
CN105910797A (en) * 2016-04-07 2016-08-31 南京航空航天大学 Optical device spectrum response measurement method and measurement device based on double sideband modulation and stimulated Brillouin scattering effect
CN106500823A (en) * 2016-12-05 2017-03-15 华南理工大学 Based on the device that thin footpath multimode fibre realizes the distributed sound wave sensing of high sensitivity
CN107741525A (en) * 2017-10-13 2018-02-27 南京航空航天大学 Photodetector Frequency Response Measuring Method and Device
CN109856057A (en) * 2019-02-27 2019-06-07 哈尔滨工业大学 Using tapered fiber as the liquid ingredient analysis device and method of medium
CN110530497A (en) * 2019-08-07 2019-12-03 北京交通大学 Interference-type optical fiber vibrating sensing demodulating system and method based on optical-electronic oscillator
CN111289089A (en) * 2020-03-20 2020-06-16 吉林大学 A Distributed Optical Fiber Sensing System Based on Heterodyne Detection Technology
CN112118043A (en) * 2020-09-18 2020-12-22 华北电力大学（保定） COTDR (coherent optical time domain reflectometry) measuring method and device based on PSK (phase Shift keying) pulse coding

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5532857A (en) * 1994-09-07 1996-07-02 Ael Industries, Inc. Wide dynamic range optical link using DSSC linearizer
CN102759371A (en) * 2012-07-19 2012-10-31 南京大学 COTDR (coherent detection based optical time-domain reflectometry) fused long-distance coherent detection brilouin optical time-domain analyzer
CN105910797A (en) * 2016-04-07 2016-08-31 南京航空航天大学 Optical device spectrum response measurement method and measurement device based on double sideband modulation and stimulated Brillouin scattering effect
CN106500823A (en) * 2016-12-05 2017-03-15 华南理工大学 Based on the device that thin footpath multimode fibre realizes the distributed sound wave sensing of high sensitivity
CN107741525A (en) * 2017-10-13 2018-02-27 南京航空航天大学 Photodetector Frequency Response Measuring Method and Device
CN109856057A (en) * 2019-02-27 2019-06-07 哈尔滨工业大学 Using tapered fiber as the liquid ingredient analysis device and method of medium
CN110530497A (en) * 2019-08-07 2019-12-03 北京交通大学 Interference-type optical fiber vibrating sensing demodulating system and method based on optical-electronic oscillator
CN111289089A (en) * 2020-03-20 2020-06-16 吉林大学 A Distributed Optical Fiber Sensing System Based on Heterodyne Detection Technology
CN112118043A (en) * 2020-09-18 2020-12-22 华北电力大学（保定） COTDR (coherent optical time domain reflectometry) measuring method and device based on PSK (phase Shift keying) pulse coding

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
李永倩等: "瑞利布里渊光时域分析系统传感性能的提升方法", 《光学学报》 *

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114918529A (en) * 2022-05-30 2022-08-19 武汉荣科激光自动化设备有限公司 Light energy focusing control method and device for laser processing

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