A high temperature sensor device based on a gas-filled hollow core optical fiber

Abstract

This invention discloses a high-temperature sensor device based on gas-filled hollow optical fiber, comprising a sensing module, a demodulation module, and a control module. The sensing module includes a hollow optical fiber, a pressure regulating unit, a coupling connection unit, a conduction optical fiber, and an optical fiber connector connected in sequence. The hollow optical fiber has a microstructure and is filled with gas. The pressure regulating unit regulates the gas pressure entering the hollow optical fiber. The coupling connection unit couples the test light field in the conduction optical fiber to the hollow optical fiber and couples the scattered light field of the hollow optical fiber to the conduction optical fiber. The demodulation module outputs the test light field and acquires the scattered light field and the test light field within the optical fiber, analyzes the coherence characteristics of the scattered light field and the test light field, and demodulates to obtain the temperature field distribution of the optical fiber link. The control module controls the pressure regulating unit to regulate the pressure and the demodulator to perform temperature demodulation. This invention solves technical problems such as multimode crosstalk, poor high-temperature stability, and the inability to perform fully distributed measurement.

Description

Technical Field

[0001] This utility model relates to the field of fiber optic sensing technology, and in particular to a high-temperature sensor device based on an air-filled hollow optical fiber. Background Technology

[0002] In extreme environments such as aircraft engines, nuclear reactors, and high-temperature chemical plants, traditional electrical sensors are susceptible to electromagnetic interference and struggle to operate stably for extended periods. Fiber optic sensors, with their advantages of being entirely photoelectric and passive, interference-resistant, corrosion-resistant, and capable of distributed measurement, have become an ideal solution for high-temperature monitoring.

[0003] Currently, commonly used fiber optic sensors include traditional quartz fiber optic high-temperature sensors and sapphire fiber optic high-temperature sensors. However, the upper temperature resistance limit of traditional quartz fiber optic high-temperature sensors is approximately 900℃, which cannot meet the ultra-high temperature (>1000℃) industrial requirements. Sapphire high-temperature fiber optic sensors use femtosecond lasers to write fiber Bragg gratings (FBGs) and utilize the wavelength shift caused by thermal expansion to achieve temperature measurement. However, sapphire FBG high-temperature sensors currently have the following problems:

[0004] 1. Solid multimode structures are usually in a state of simultaneous resonance of multiple peaks. Wavelength drift at high temperatures can easily cause difficulties in signal demodulation and there is a multimode crosstalk problem.

[0005] 2. Femtosecond processing equipment is expensive, and the FBG structure is prone to failure at extreme high temperatures (>1500℃), resulting in poor high-temperature stability.

[0006] 3. The multi-sapphire FBG high-temperature sensor series technology is still a quasi-distributed measurement. The number and density of single-fiber measurements are still limited, making it difficult to achieve fully distributed measurement. Utility Model Content

[0007] Based on this, this application provides a high-temperature sensor device based on air-filled hollow optical fiber, which solves the technical problems of multimode crosstalk, poor high-temperature stability, and inability to perform fully distributed measurement.

[0008] In a first aspect, this application provides a high-temperature sensor device based on gas-filled hollow optical fiber, comprising:

[0009] The sensing module includes a hollow optical fiber, a pressure regulating unit, a coupling connection unit, a conducting optical fiber, and an optical fiber connector connected in sequence. The hollow optical fiber has a microstructure inside and is filled with gas. The pressure regulating unit is configured to regulate the gas pressure value of the gas injected into the hollow optical fiber. The coupling connection unit is configured to couple the test light field in the conducting optical fiber to the hollow optical fiber and to couple the scattered light field of the hollow optical fiber to the conducting optical fiber.

[0010] The demodulation module includes a demodulator aligned with the fiber optic connector and configured to output a test optical field, acquire the scattered optical field and the test optical field within the fiber, analyze the coherence characteristics of the scattered optical field and the test optical field, and demodulate to obtain the temperature field distribution of the fiber optic link.

[0011] The control module is configured to control the air pressure regulating unit to perform air pressure regulation and the demodulator to perform temperature demodulation.

[0012] As a preferred embodiment, the hollow optical fiber is a sapphire hollow optical fiber, and its cross-sectional shape includes one of photonic crystal type, single-layer type, and multi-layer type.

[0013] As a preferred embodiment, the coupling connection unit integrates a gas channel and an alignment coupling structure:

[0014] The gas channel is configured to transmit the gas to the hollow fiber, and the alignment coupling structure is configured to couple the test light field into the hollow fiber, and simultaneously collimate the scattered light field and couple it to the fiber connector.

[0015] As a preferred embodiment, the demodulator is an optical frequency domain reflectometer, which includes a swept frequency light source, a photodetector, and a coupler.

[0016] As a preferred embodiment, the demodulator is a Brillouin scattering time-domain meter, comprising a single-frequency light source, an acousto-optic modulator, and a spectrum analyzer.

[0017] As a preferred embodiment, the conductive optical fiber is a quartz-based hollow-core optical fiber, and the mode field diameter matching error with the hollow-core optical fiber is ≤10%.

[0018] As a preferred embodiment, the hollow optical fiber has a core diameter of 10-500 μm and a cladding wall thickness of 1 / 5-1 / 2 of the core diameter.

[0019] As a preferred embodiment, the gas includes N2, CO2, inert gases, and mixtures of at least two inert gases.

[0020] As a preferred embodiment, the high-temperature sensor device has a temperature measurement error of ≤±1℃ at 1500℃ and a spatial resolution of ≤1cm.

[0021] Based on the same inventive concept, this application also provides a control method for a high-temperature sensor device based on an air-filled hollow optical fiber, used to control the high-temperature sensor device based on an air-filled hollow optical fiber provided in the first aspect, comprising:

[0022] The air pressure control unit fills the hollow optical fiber with gas and stabilizes it to a preset pressure value.

[0023] The control demodulation module outputs a test optical field, which is then introduced into a hollow optical fiber via a coupling connection unit.

[0024] The control demodulation module receives the scattered light field from the hollow fiber and obtains the temperature field distribution of the fiber link by analyzing the coherence characteristics of the test light field and the scattered light field.

[0025] In summary, the high-temperature sensor device based on gas-filled hollow optical fiber provided in this application, by combining the unique microstructure design of gas-filled hollow optical fiber with the high stability of sapphire material, can achieve highly concentrated transmission of light waves in the gas-filled region, greatly enhancing the interaction efficiency between light and the medium and significantly reducing transmission loss. At the same time, it can also realize the applicability and high reliability of optical fiber in extreme high temperature, high pressure, and high radiation environments, and can meet the distributed high temperature measurement needs of various application environments. Attached Figure Description

[0026] Figure 1 A schematic diagram of a high-temperature sensor device based on an air-filled hollow optical fiber provided in this application;

[0027] Figure 2 for Figure 1 An enlarged schematic diagram of a hollow-core optical fiber in region A;

[0028] Figure 3 A schematic diagram of the cross-section of a hollow optical fiber provided in this application;

[0029] Figure 4 This is a schematic diagram of the demodulator based on the principle of optical frequency domain reflectometer provided in this application;

[0030] Figure 5 The provided diagram shows the structural principle of a demodulator based on the Brillouin scattering time-domain meter principle.

[0031] Figure 6 A schematic diagram of a control method for a high-temperature sensor device based on an air-filled hollow optical fiber provided in this application.

[0032] Explanation of reference numerals in the attached figures:

[0033] 10. Sensing module; 20. Demodulation module; 1. Hollow-core optical fiber; 2. Gas; 3. Gas pressure regulation unit; 4. Coupling connection unit; 5. Conducting optical fiber; 6. Optical fiber connector; 7. Demodulator. Detailed Implementation

[0034] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. It is understood that the specific embodiments described herein are merely illustrative of the present application and not intended to limit it. Furthermore, it should be noted that, for ease of description, only the parts relevant to the present application are shown in the drawings, not the entire structure. Various modifications and variations can be made to the present application without departing from its spirit or scope, which will be apparent to those skilled in the art. Therefore, the present application is intended to cover modifications and variations falling within the scope of the corresponding claims (the claimed technical solutions) and their equivalents. It should be noted that the implementation methods provided in the embodiments of the present application can be combined with each other without contradiction.

[0035] Figure 1 This is a schematic diagram of a high-temperature sensor device based on an air-filled hollow optical fiber, as provided in this application. Figure 2 for Figure 1 An enlarged schematic diagram of a hollow-core optical fiber in region A. Figure 3 This application provides a schematic diagram of the cross-section of a hollow optical fiber, with reference to... Figures 1-3 This application provides a high-temperature sensor device based on gas-filled hollow optical fiber, which can be used for high-temperature detection in extreme environments such as aero-engines, nuclear reactors, and high-temperature chemical plants. The high-temperature sensor device based on gas-filled hollow optical fiber provided in this application includes a sensing module 10, a demodulation module 20, and a control module. The sensing module 10 includes a hollow optical fiber 1, a pressure regulating unit 3, a coupling connection unit 4, a conductive optical fiber 5, and an optical fiber connector 6 connected in sequence. The demodulation module 20 includes a demodulator 7, which is aligned with the optical fiber connector 6. The control module can be a separate module or integrated into the demodulation module 20; this application does not impose any limitations on this.

[0036] refer to Figure 1 The hollow fiber 1 has a microstructure inside and is filled with gas 2 to form a gas-filled hollow fiber with a microstructure design in the core.

[0037] Specifically, air-filled hollow fiber is a special type of optical fiber structure, with its core filled with air or gas. It possesses unique advantages such as compressibility, ease of mixing, low loss, high damage threshold, tunable dispersion and nonlinearity, ultra-wide bandwidth, and good environmental adaptability. Unlike traditional single-mode fiber or other solid-core special fibers, the scattering characteristics of air-filled hollow fiber do not depend on the elastic properties of the solid material, but are determined by the density, sound velocity, and refractive index of the gas, thus overcoming the limitations imposed by the inherent properties of solid fiber core materials. This application allows for flexible adjustment of optical field characteristics, such as scattering coefficient, dispersion delay, and measurement sensitivity, by controlling the pressure, temperature, or composition of the gas 2 inside the hollow fiber 1. This overcomes the difficulty in controlling the inherent properties of traditional optical fiber materials.

[0038] Optionally, such as Figure 2 and Figure 3 As shown, the hollow fiber 1 of this application is a sapphire hollow fiber, and its cross-sectional shape includes one of photonic crystal type, single-layer type, and multi-layer type.

[0039] Specifically, sapphire optical fiber has the chemical composition α-Al₂O₃ and a melting point as high as 2040-2053℃. It possesses superior properties such as broad-spectrum transparency, high-temperature resistance, radiation resistance, and corrosion resistance, making it an ideal optical sensor material for sensing applications in harsh environments. This application uses sapphire material to draw sapphire hollow optical fibers, and the microstructure of the sapphire hollow optical fibers can be configured into various structural forms according to application requirements.

[0040] For example, such as Figure 2 The optical fibers shown are of various types, including photonic crystal, single-layer, and multilayer. Their dimensions can also be adjusted as needed. Optionally, the core diameter of the hollow-core fiber 1 is 10-500 μm, and the cladding thickness is 1 / 5-1 / 2 of the core diameter.

[0041] Gas 2 includes N2, CO2, inert gases and mixtures of at least two inert gases, or other gases and mixtures thereof.

[0042] This application, by combining the unique microstructure design of gas-filled hollow optical fiber with the high stability of sapphire material, can achieve highly concentrated transmission of light waves in the gas-filled region, greatly enhancing the interaction efficiency between light and the medium, significantly reducing transmission loss, and also enabling the optical fiber to achieve applicability and high reliability in extreme high temperature, high pressure, and high radiation environments.

[0043] In addition, another important characteristic of the sapphire gas-filled hollow fiber provided in this application is that temperature variables have a very good sensitivity to light field scattering characteristics, while deformation variables have little impact on light field scattering characteristics. This can largely eliminate the crosstalk of temperature and strain in conventional solid-core sensors, enabling more accurate measurement of temperature field quantities.

[0044] Furthermore, by adjusting the gas pressure of the gas 2 filled into the hollow optical fiber 1 through the gas pressure regulating unit 3, the sensitivity of the sensor can be adjusted.

[0045] For example, the pressure regulating unit 3 uses a pressure regulating valve to input the gas 2 from the external gas pipeline to the coupling connection unit 4, and finally fills the hollow optical fiber 1 through the coupling connection unit 4.

[0046] Among them, the gas pressure value of gas 2 in hollow optical fiber 1 is positively correlated with the sensitivity of the sensor.

[0047] As an example, by adjusting parameters such as gas flow rate and gas concentration input to the hollow fiber 1 by the gas pressure regulating unit 3, the gas pressure value of the gas 2 in the hollow fiber 1 can be increased, thereby improving the sensitivity of the sensor and meeting the requirements of different measurement ranges and resolutions.

[0048] The coupling connection unit 4 is configured to couple the test optical field in the transmission optical fiber 5 to the hollow optical fiber 1 and to couple the scattered optical field of the hollow optical fiber 1 to the transmission optical fiber 5.

[0049] Optionally, the coupling connection unit 4 integrates a gas channel and an alignment coupling structure. The gas channel is configured to transmit gas 2 to the hollow fiber 1, and the alignment coupling structure is configured to couple the test light field to the hollow fiber 1, while simultaneously collimating the scattered light field and coupling it to the fiber connector 6.

[0050] Specifically, one end of the gas channel of the coupling connection unit 4 is connected to the gas pressure regulating unit 3, and the other end is connected to the hollow fiber 1, serving to transmit gas 2 to the hollow fiber 1. The alignment and coupling structure of the coupling connection unit 4 can realize the coupling of the optical field between the conventional transmission fiber 5 and the hollow fiber 1. It can couple the test optical field from the transmission fiber 5 into the hollow fiber 1, and it can also receive the backscattered optical field from the hollow fiber 1 and couple the scattered optical field into the transmission fiber 5, and finally input it to the demodulator 7 through the fiber connector 6.

[0051] The coupling connection unit 4 may also include a precision three-dimensional adjustment frame and a high-temperature resistant lens group. The precision three-dimensional adjustment frame adjusts the alignment of each connecting device, and the high-temperature resistant lens group realizes optical field coupling. The working temperature range is -200℃ to 2000℃.

[0052] Optionally, the transmission fiber 5 is a quartz-based hollow fiber, with a mode field diameter matching error of ≤10% with the hollow fiber 1. This configuration helps to improve the optical signal transmission efficiency and the demodulation accuracy of the temperature field.

[0053] The demodulator 7 is configured to output the test optical field and acquire the scattered optical field and the test optical field within the optical fiber, analyze the coherence characteristics of the scattered optical field and the test optical field, and demodulate to obtain the temperature field distribution of the optical fiber link.

[0054] Specifically, the test light field output by the light source in the demodulator 7 is transmitted to the hollow fiber 1 through the fiber connector 6, the transmission fiber 5, and the coupling connection unit 4. At the same time, the scattered light field of the hollow fiber 1 is received, and the coherence characteristics of the scattered light field and the test light field are analyzed to demodulate and obtain the temperature field distribution of the fiber optic link.

[0055] The control module is connected to the air pressure regulating unit 3 and the demodulator 7, and is configured to control the air pressure regulating unit 3 to perform air pressure regulation and the demodulator 7 to perform temperature demodulation.

[0056] The control module can be an integrated circuit (IC), processor, microprocessor, such as a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. The control module stores control programs for at least the pressure regulating unit 3 and the demodulator 7.

[0057] Figure 4 This is a schematic diagram of the demodulator based on the principle of optical frequency domain reflectometer provided in this application. (Refer to...) Figure 4 The demodulator 7 is an optical frequency domain reflectometer (OFDR), which includes at least a swept frequency light source 01, a photodetector 02, and a coupler 03.

[0058] As an example, combined Figure 1 and Figure 4 Taking the demodulator 7, which uses an optical frequency domain reflectometer (OFDR), as an example, the demodulation principle is as follows:

[0059] refer to Figure 4 Figure (a) shows the test light field emitted from the swept-frequency light source 01. The optical frequency of this test light field changes linearly with time. (Combined with...) Figure 1 and Figure 4 In Figure (b), a portion of the test optical field serves as the reference light, while another portion is transmitted through fiber optic connector 6, conducting fiber optic cable 5, and coupling connector 4 to the hollow fiber 1. When the temperature of the hollow fiber 1 changes, the light field scattering characteristics within it exhibit high sensitivity to temperature variations in the external environment. The backscattered light field signal is transmitted via coupling connector 4, conducting fiber optic cable 5, and fiber optic connector 6 to coupler 03 of demodulator 7, resulting in coherent interference between the backscattered light field signal and the test optical field emission. Combined with coherent detection technology, photodetector 02 detects the backscattered Rayleigh signal in the fiber filling gas 2, demodulating and acquiring Rayleigh scattering information for the entire hollow fiber 1, thus achieving high-resolution (mm-level) and high-precision (<1℃) distributed measurement of the fiber optic link temperature field.

[0060] Figure 5 This is a schematic diagram of the demodulator based on the Brillouin scattering time-domain meter principle, provided in the application. (Reference) Figure 5The demodulator 7 is a Brillouin optical time-domain reflectometer (BOTDR), which includes at least a single-frequency light source 04, an acousto-optic modulator 07, and a coherent detector 09. For example, the single-frequency light source 04 is a fiber laser.

[0061] As an example, combined Figure 1 and Figure 5 Taking the demodulator 7, which uses a Brillouin scattering time-domain meter (BOTDR), as an example, the demodulation principle is as follows:

[0062] The single-frequency laser output from the fiber laser is split by beam splitter 05. One portion of the single-frequency laser, used as a reference beam, enters the optical frequency shifter 06 for frequency shifting before entering the coherent detector 09. The other portion of the single-frequency laser is modulated by the acousto-optic modulator (AOM) 07, amplified by the erbium-doped fiber amplifier (EDFA) 08, and then enters the hollow fiber 1 of the sensing module 10. When the single-frequency laser propagates through the gas-filled medium 2, it causes inelastic scattering of gas acoustic phonons. When the temperature of the hollow fiber 1 changes, Brillouin scattering occurs. This scattered light field is transmitted in the reverse direction to the coherent detector 09 and interferes with the frequency-shifted single-frequency laser. Data acquisition and DSP (Data Acquisition and Digital Signal Processing) 10 achieves real-time monitoring of the temperature field by measuring and analyzing the Brillouin frequency shift distribution along the fiber. Users can also control and view the temperature field distribution through the user interface (UI) 11.

[0063] Among them, parameters such as the frequency shift of Brillouin scattering depend on the acoustic, elastic, and thermoelastic properties of the hollow fiber 1.

[0064] It should be noted that the demodulator 7 provided in this application embodiment is not limited to these two forms. Other similar test demodulation methods that use this high-temperature sensor structure with sapphire gas-filled hollow optical fiber are also within the protection scope of this patent.

[0065] The demodulation module provided in this application transmits the test light field output by the back-end demodulator to the hollow fiber through the fiber connector, the transmission fiber, and the coupling connection unit. At the same time, it acquires the scattered light field of the front-end sensing module and transmits it to the demodulator, thereby realizing detailed demodulation of temperature measurement.

[0066] Based on the above embodiments, the high-temperature sensor device provided in this application has a temperature measurement error of ≤±1℃ at 1500℃ and a spatial resolution of ≤1cm, which meets the requirements of different measurement ranges and resolutions.

[0067] The high-temperature sensor device based on air-filled hollow optical fiber provided in this application, compared with traditional quartz high-temperature sensors and sapphire high-temperature optical fiber sensors, can avoid the simultaneous resonance of multiple peaks in solid multimode fiber optic (FBG) fabrication, which causes signal demodulation difficulties due to wavelength drift at high temperatures, thus solving the problem of multimode crosstalk. This device has a simple structure, low cost, and does not require expensive femtosecond processing equipment. It still has extremely high temperature stability at extreme high temperatures (>1500℃) and can realize fully distributed high-temperature measurement.

[0068] Based on the same inventive concept, this application also provides a control method for a high-temperature sensor device based on an air-filled hollow optical fiber, used to control the high-temperature sensor device based on an air-filled hollow optical fiber provided in the above embodiments. Figure 6 This application provides a high-temperature transmission method based on air-filled hollow optical fiber.

[0069] A schematic diagram of the control method for the sensor device, see reference. Figures 1-6 The control methods include:

[0070] S101. Control the air pressure control unit to fill the hollow optical fiber with gas and stabilize it to the preset pressure value.

[0071] For details, please refer to Figure 1 The control module controls the air pressure regulating unit 3 to fill the hollow fiber 1 with gas 2 at a preset pressure value based on the preset pressure value. At the same time, by controlling parameters such as gas input time and filling rate, the pressure of gas 2 in the hollow fiber 1 is stabilized to the preset pressure value.

[0072] S102, The test optical field output by the control demodulation module is introduced into the hollow optical fiber through the coupling connection unit.

[0073] For details, please refer to Figure 1 The control module controls the light source in the demodulator 7 to output a test light field. The test light field is transmitted to the hollow fiber 1 through the fiber connector 6, the transmission fiber 5, and the coupling connection unit 4. The gas 2 in the hollow fiber 1 emits light and scatters light under the action of the test light field. When the external temperature changes, the scattered light field changes.

[0074] S103, The control demodulation module receives the scattered light field of the hollow optical fiber, and obtains the temperature field distribution of the optical fiber link by analyzing the coherence characteristics of the test light field and the scattered light field.

[0075] For details, please refer to Figure 1The control module controls the demodulator 7 to acquire the scattered light field of the hollow fiber. The demodulator 7 is based on the demodulation principle of optical frequency domain reflectometer (OFDR), or the demodulation principle of Brillouin scattering time domain meter (BOTDR), or other forms of demodulation principle, and obtains the temperature field distribution of the fiber link based on the coherence characteristics of the test light field and the scattered light field.

[0076] The control method for the high-temperature sensor device based on air-filled hollow optical fiber provided in this application can effectively control the high-temperature sensor device based on air-filled hollow optical fiber to measure the temperature field distribution in real time. It has the advantages of accurate measurement, fast response, no multimode crosstalk, strong stability, and accurate measurement in a variety of high-temperature environments.

[0077] Note that the above description is merely a preferred embodiment of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein. Features of the various embodiments of the present invention can be partially or wholly coupled or combined with each other, and can cooperate and be technically driven in various ways. Various obvious changes, readjustments, combinations, and substitutions can be made by those skilled in the art without departing from the protection scope of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments. Many other equivalent embodiments may be included without departing from the concept of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A high-temperature sensor device based on gas-filled hollow optical fiber, characterized in that, include: The sensing module includes a hollow optical fiber (1), a pressure regulating unit (3), a coupling connection unit (4), a conducting optical fiber (5), and an optical fiber connector (6) connected in sequence. The hollow optical fiber (1) has a microstructure and is filled with gas (2). The pressure regulating unit (3) is configured to regulate the pressure of the gas (2) injected into the hollow optical fiber (1). The coupling connection unit (4) is configured to couple the test light field in the conducting optical fiber (5) to the hollow optical fiber (1) and to couple the scattered light field of the hollow optical fiber (1) to the conducting optical fiber (5). The demodulation module includes a demodulator (7), which is aligned with the optical fiber connector (6) and configured to output a test optical field and acquire the scattered optical field and the test optical field in the optical fiber, and analyze the coherence characteristics of the scattered optical field and the test optical field, and demodulate to obtain the temperature field distribution of the optical fiber link. The control module is configured to control the air pressure regulating unit (3) to perform air pressure regulation and the demodulator (7) to perform temperature demodulation.

2. The high-temperature sensor device according to claim 1, characterized in that, The hollow fiber (1) is a sapphire hollow fiber, and its cross-sectional shape includes one of photonic crystal type, single-layer type and multi-layer type.

3. The high-temperature sensor device according to claim 1, characterized in that, The coupling connection unit (4) integrates a gas channel and an alignment coupling structure: The gas channel is configured to transmit the gas (2) to the hollow fiber (1), and the alignment coupling structure is configured to couple the test light field to the hollow fiber (1) and simultaneously collimate the scattered light field and couple it to the fiber connector (6).

4. The high-temperature sensor device according to claim 1, characterized in that, The demodulator (7) is an optical frequency domain reflectometer, which includes a swept frequency light source, a photodetector and a coupler.

5. The high-temperature sensor device as described in claim 1, characterized in that, The demodulator (7) is a Brillouin scattering time-domain meter, which includes a single-frequency light source, an acousto-optic modulator, and a spectrum analyzer.

6. The high-temperature sensor device according to claim 1, characterized in that, The transmission fiber (5) is a quartz-based hollow fiber, and the mode field diameter matching error with the hollow fiber (1) is ≤10%.

7. The high-temperature sensor device according to claim 1, characterized in that, The hollow fiber (1) has a core diameter of 10-500 μm and a cladding wall thickness of 1 / 5-1 / 2 of the core diameter.

8. The high-temperature sensor device according to claim 1, characterized in that, The gas (2) includes N2, CO2, inert gases, and a mixture of at least two inert gases.

9. The high-temperature sensor device according to claim 1, characterized in that, The high-temperature sensor device has a temperature measurement error of ≤±1℃ at 1500℃ and a spatial resolution of ≤1cm.

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