High-temperature-resistant fiber optic thermo-acoustic-vibration tri-parameter sensor

Abstract

The application belongs to the technical field of high-temperature sensing, and particularly relates to a high-temperature-resistant optical fiber thermal-acoustic-vibration three-parameter sensor, which comprises a packaging base and a packaging cover plate, a sensing optical fiber and a sensitive diaphragm are arranged in the packaging base, a first Bragg grating and a second Bragg grating with different central wavelengths are arranged on the sensing optical fiber, a hollow-core optical fiber is arranged at the end of the sensing optical fiber, and a punching area is arranged on the hollow-core optical fiber. The Bragg gratings with two groups of different central wavelengths are used to measure temperature and vibration signals, the hollow-core optical fiber at the end of the sensing optical fiber is used to form a Fabry-Perot resonant cavity to test noise signals, and the synchronous measurement of thermal-acoustic-vibration three parameters under high-temperature conditions is realized. The consistency of the measurement data is strong, and the high-temperature-resistant optical fiber thermal-acoustic-vibration three-parameter sensor can be widely applied to high-temperature and high-pressure harsh environments such as aerospace, missile launching and nondestructive testing.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of high-temperature sensing in aerospace and the like, and particularly relates to a high-temperature-resistant optical fiber thermal-acoustic-vibration three-parameter sensor. BACKGROUND

[0002] With the rapid development of aerospace technology, solid rockets have been widely used in commercial aerospace due to their unique advantages such as fast launch speed, large power and low cost. However, during the working process of the solid rocket engine combustion chamber, high temperature, strong vibration and strong noise have a significant impact on the structural stability, often causing irreversible damage to the engine structure, and even causing serious safety accidents. At present, due to material limitations, traditional electrical sensors cannot work normally in high-temperature environments, which greatly limits their application in solid rocket engine monitoring.

[0003] Optical fiber sensors have been widely used in multi-physical quantity measurement in extreme harsh environments due to their strong anti-electromagnetic interference ability, long transmission distance and high temperature resistance. Among them, the sensors based on fiber Bragg grating and fiber Fabry-Perot interference principle are the two most widely used types of optical fiber sensors. In the past few decades, optical fiber sensing technology has experienced rapid development and has been successfully applied to many key fields such as bridge monitoring, aerospace, petrochemical industry, etc. In practical applications, temperature, vibration and noise are crucial physical parameters, and their changes are often directly related to and reflect the running state and safety of the object. However, the current optical fiber sensors still have limitations. Optical fiber sensors can usually only realize single-parameter in-situ measurement at a certain point, and cannot simultaneously acquire temperature, vibration and noise, which are three key physical parameters. This limitation greatly limits the application range of fiber Bragg grating sensors in complex environments, making it necessary to use multiple sensors for measurement in situations where temperature, vibration and noise need to be monitored simultaneously, which not only increases the complexity and cost of the system, but also may cause errors in the measurement results due to the mutual influence between the sensors.

[0004] Therefore, in order to better meet the actual needs of the aerospace field, it is necessary to improve the structure of related sensors to realize the synchronous acquisition of solid rocket engine combustion temperature, vibration and noise signals. SUMMARY

[0005] In order to overcome the difficulty of the existing optical fiber sensors in effectively and simultaneously acquiring temperature, vibration and noise signals in high-temperature harsh environments, the present application proposes a high-temperature-resistant optical fiber thermal-acoustic-vibration three-parameter sensor to realize accurate measurement of temperature, vibration and noise signals in harsh environments such as high temperature and high pressure.

[0006] In order to solve the above technical problems, the technical scheme adopted by the present application is: a high-temperature-resistant optical fiber thermo-acoustic-vibration three-parameter sensor, comprising: a packaging base and a packaging cover plate, the packaging base is provided with a first cavity; the packaging cover plate is arranged above the packaging base and is used for packaging the first cavity;

[0007] Both ends of the packaging base are respectively provided with a first through hole and a second through hole which are in communication with the first cavity; a sensitive diaphragm groove for placing a sensitive diaphragm is arranged on the bottom surface of the first cavity, and a second cavity is arranged at the bottom of the sensitive diaphragm groove; both ends of the sensitive diaphragm are fixedly arranged in the sensitive diaphragm groove, and the first cavity and the second cavity form a vibration space of the sensitive diaphragm;

[0008] A sensing optical fiber is fixedly arranged at the bottom of the first cavity in the packaging base, the end of the sensing optical fiber is arranged in the second through hole, and the other end extends to the outside of the packaging base through the first through hole after passing above the sensitive diaphragm; the sensing optical fiber is provided with first and second Bragg gratings with different central wavelengths, the first Bragg grating is fixed at the bottom of the first cavity, and the second Bragg grating is fixed on the sensitive diaphragm; an air-core optical fiber is arranged on one side of the sensing optical fiber close to the second through hole, the air-core optical fiber is provided with a punching area which transversely penetrates the optical fiber core, and both end faces of the air-core optical fiber form a Fabry-Perot resonant cavity for measuring an acoustic signal; the first and second Bragg gratings are respectively used for measuring a temperature signal and a vibration signal.

[0009] The sensitive diaphragm is in the shape of a cantilever beam, which comprises triangular supports on both sides and a cantilever beam at the center; the triangular supports are arranged in the sensitive diaphragm groove, and the second cavity is located below the cantilever beam.

[0010] The sensitive diaphragm is fixed on the bottom surface of the sensitive diaphragm groove by high-temperature inorganic glue.

[0011] The bottom of the first cavity is also provided with a first optical fiber groove and a second optical fiber groove, and the first and second optical fiber grooves are respectively arranged on both sides of the sensitive diaphragm groove and are used for arranging the sensing optical fiber.

[0012] A cover plate groove is further arranged above the packaging base, the cover plate groove is matched with the outer shape of the packaging cover plate, and is used for placing the packaging cover plate.

[0013] The high-temperature-resistant optical fiber thermo-acoustic-vibration three-parameter sensor further comprises a fiber armored tube, the fiber armored tube is arranged in the first through hole and is used for protecting the sensing optical fiber.

[0014] A first threaded hole which is perpendicular to the first through hole is arranged on the packaging base, and the first threaded hole is used for arranging a screw to fix the fiber armored tube.

[0015] A second threaded hole is arranged at the bottom of the packaging base, and the second threaded hole is used for arranging a screw to fix the sensor.

[0016] The material of the sensitive diaphragm and the sensing optical fiber is quartz, and the material of the packaging base and the packaging cover plate is stainless steel.

[0017] The assembling method of the high-temperature-resistant optical fiber thermo-acoustic-vibration three-parameter sensor comprises the following steps:

[0018] Step S: uniformly apply high-temperature inorganic glue between the sensitive diaphragm groove and the sensitive diaphragm, place the sensitive diaphragm in the sensitive diaphragm groove, and use an oven to bake and solidify the high-temperature inorganic glue;

[0019] Step S: uniformly apply high-temperature inorganic glue at the position where the sensing optical fiber contacts the packaging base and the quartz sensitive diaphragm, place the sensing optical fiber on the packaging base and the sensitive diaphragm, and use an oven to bake and solidify the high-temperature inorganic glue;

[0020] Step S: pass the fiber armor tube outside the sensing optical fiber and into the first through hole of the packaging base, and use a screw to fixedly connect the fiber armor tube and the packaging base;

[0021] Step S: fixedly connect the packaging cover plate and the packaging base by spot welding around the packaging cover plate and the packaging base.

[0022] Compared with the prior art, the present application has the following beneficial effects:

[0023] 1. The present application provides a high-temperature-resistant optical fiber thermo-acoustic-vibration three-parameter sensor, which adopts two groups of Bragg gratings with different center wavelengths to realize the measurement of temperature and vibration signals, and sets a perforated hollow core optical fiber at the end of the sensing optical fiber to form a Fabry-Perot resonant cavity to realize the test of noise signals; specifically, the first Bragg grating is pasted on the surface of the packaging base and is only sensitive to temperature, and the actual temperature change can be detected by observing the center wavelength drift of its reflection signal; at the same time, the second Bragg grating is pasted on the surface of the quartz sensitive diaphragm and is sensitive to vibration and temperature, and the actual temperature and vibration superimposed change can be detected by observing the center wavelength drift of its reflection signal; in addition, the hollow core optical fiber forming the Fabry-Perot resonant cavity is pasted at the tail end of the packaging base and is sensitive to noise signals, and the detection of noise signals can be realized by monitoring the free spectral region of its reflection spectrum. By using the first Bragg grating to compensate the influence of temperature on the second Bragg grating, the size of the temperature, vibration and noise signals in the environment can be simultaneously calculated, therefore, the present application can realize the synchronous measurement of thermo-acoustic-vibration three parameters under high temperature conditions through a simple structure, and the consistency of the measurement data is strong.

[0024] 2、The application realizes the packaging of sensing core devices through the packaging cover plate and the packaging base, and the packaging materials are all made of 310S stainless steel, so that full-rigid connection of the sensor device is realized, the stability of the optical sensing signal of the sensor in different temperature, vibration and noise environments is ensured, and the test precision of the sensor in a high-temperature environment is improved.

[0025] In conclusion, the application realizes the synchronous monitoring of temperature, vibration and noise signals for the first time, breaks through the working temperature limit of the traditional sensor, realizes the integration of multiple physical parameters, and has practical application value in high-temperature and high-pressure harsh environments such as aerospace, missile launching and nondestructive testing. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 A high-temperature-resistant optical fiber thermal-acoustic-vibration three-parameter sensor provided by the embodiment of the application is shown in the figure.

[0027] Figure 2 An internal structure diagram of a high-temperature-resistant optical fiber thermal-acoustic-vibration three-parameter sensor provided by the embodiment of the application is shown in the figure.

[0028] Figure 3 A sectional structure diagram of a high-temperature-resistant optical fiber thermal-acoustic-vibration three-parameter sensor provided by the embodiment of the application is shown in the figure.

[0029] Figure 4 A three-dimensional structure diagram of the packaging base in the embodiment of the application is shown in the figure.

[0030] Figure 5 A local structure diagram of the hole-punching hollow core fiber in the sensing optical fiber in the embodiment of the application is shown in the figure.

[0031] Figure 6 A structure diagram of the sensitive diaphragm in the embodiment of the application is shown in the figure.

[0032] Figure 7 A reflection spectrum diagram of the sensing optical fiber obtained in the embodiment of the application is shown in the figure.

[0033] In the figure, 1 is a packaging cover plate, 2 is a packaging base, 3 is a sensitive diaphragm, 4 is an optical fiber armored tube, 5 is a sensing optical fiber, 21 is a second threaded hole, 22 is a first threaded hole, 23 is a second cavity, 24 is a first cavity, 25 is a second through hole, 26 is a sensitive diaphragm groove, 27 is a first optical fiber groove, 28 is a first through hole, 29 is a cover plate groove, 210 is a second optical fiber groove, 31 is a triangular support, 32 is a cantilever beam, 51 is a first Bragg grating, 52 is a second Bragg grating, 53 is a hole-punching hollow core fiber, and 54 is a hole-punching area. DETAILED DESCRIPTION

[0034] In order to make the purposes, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below. Obviously, the described embodiments are some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of the present application.

[0035] As shown in Figures 1-4 The present embodiment provides a high-temperature-resistant optical fiber thermo-acoustic-vibration tri-parameter sensor, which comprises a packaging base 1 and a packaging cover plate 2, the packaging base 1 is internally provided with a first cavity 24, and the packaging cover plate 2 is arranged above the packaging base 1 and used for packaging the first cavity 24.

[0036] The two ends of the packaging base 1 are respectively provided with a first through hole 28 and a second through hole 25 which are in communication with the first cavity 24, a sensitive diaphragm groove 26 for placing a sensitive diaphragm 3 is arranged on the bottom surface of the first cavity 24, and a second cavity 23 is arranged at the bottom of the sensitive diaphragm groove 26; the sensitive diaphragm 3 is fixedly arranged in the sensitive diaphragm groove 26, and the first cavity 24 and the second cavity 23 form a vibration space of the sensitive diaphragm 3.

[0037] The packaging base 1 is fixedly provided with a sensing optical fiber 5, the sensing optical fiber 5 is arranged in the second through hole 25, and the other end of the sensing optical fiber 5 extends to the outside of the packaging base 1 through the first through hole 28 after passing above the sensitive diaphragm 3; the sensing optical fiber 5 is provided with a first Bragg grating 51 and a second Bragg grating 52 with different center wavelengths, the first Bragg grating 51 is fixed at the bottom of the first cavity 24, the second Bragg grating 52 is fixed on the sensitive diaphragm 3, and the first Bragg grating 51 and the second Bragg grating 52 are respectively used for measuring temperature signals and vibration signals.

[0038] As shown in Figure 5 In the present embodiment, the sensing optical fiber 5 is provided with a hollow core optical fiber 53 fixed at the bottom of the first cavity 24 on one side close to the second through hole 25, the two end faces of the hollow core optical fiber 53 form a Fabry-Perot resonant cavity, and the hollow core optical fiber 53 is provided with a punching area 54 which transversely penetrates the optical fiber core. External acoustic pressure signals enter the first cavity 24 through the second through hole 25 and are further transmitted to the Fabry-Perot resonant cavity through the punching area 54, and then the Fabry-Perot resonant cavity is sensitive to noise, and noise signal measurement can be realized by monitoring the change of the free spectral range of the Fabry-Perot resonant cavity.

[0039] Specifically, in the embodiment, the method for arranging the hollow core fiber 53 is as follows: a fiber fusion splicer is used to fuse a section of the hollow core fiber 53 to the end of the sensing fiber 5, and then fuse a section of the sensing fiber 5 to the end of the hollow core fiber 53, so that the two ends of the hollow core fiber 53 form a Fabry-Perot resonant cavity. Finally, the fiber of the hollow core fiber 53 is perforated by a femtosecond laser to obtain a perforated area 54, so as to realize the propagation of the sound pressure signal to the Fabry-Perot resonant cavity. Specifically, in the embodiment, the core diameter of the hollow core fiber 53 is 75 μm, the cladding diameter is 125 μm, and the length is about 800 μm. The length of the perforated area 54 is 60 μm, and the width is 30 μm.

[0040] In addition, in the embodiment, the first Bragg grating 51 and the second Bragg grating 52 are both processed by femtosecond laser, which can ensure that the gratings will not be erased due to high temperature environment, and have the advantages of stability and high reliability.

[0041] Specifically, as shown in Figure 6 In the embodiment, the sensitive diaphragm 3 is in the shape of a cantilever beam, which includes triangular supports 31 on both sides and a cantilever beam 32 in the center; as shown in Figure 2 The triangular supports 31 are arranged in the sensitive diaphragm groove 26, and the second cavity 23 is located below the cantilever beam 32. The length of the second cavity 23 is slightly greater than the length of the cantilever beam 32, so as to ensure that the cantilever beam 32 is completely suspended, thereby enhancing the vibration sensitivity of the sensor, and the triangular supports 31 at both ends of the sensitive diaphragm 3 are fixed on the bottom surface of the sensitive diaphragm groove 26.

[0042] Specifically, in the embodiment, the depth of the sensitive diaphragm groove 26 is greater than or equal to the thickness of the sensitive diaphragm 3, and the sensitive diaphragm 3 is fixed on the bottom surface of the sensitive diaphragm groove 26 by high-temperature inorganic glue.

[0043] Specifically, the first through hole 28 and the second through hole 25 are both square.

[0044] Specifically, in the embodiment, the first cavity 24 further comprises a first fiber groove 27 and a second fiber groove 210 at the bottom, and the first fiber groove 27 and the second fiber groove 210 are respectively located on both sides of the sensitive diaphragm groove 26 for arranging the sensing fiber 5.

[0045] Specifically, in the embodiment, the first Bragg grating 51 in the sensing optical fiber 5 is fixed in the first optical fiber groove 27 by high-temperature inorganic glue, is only sensitive to temperature, and can detect actual temperature changes by measuring the center wavelength drift of reflected light. The second Bragg grating 52 in the sensing optical fiber 5 is fixed together with the sensitive diaphragm 3 by high-temperature inorganic glue, is sensitive to temperature and vibration signals under the vibration of the sensitive diaphragm 3, and can detect changes of actual temperature and vibration superposition by observing the center wavelength drift of reflected light of the second Bragg grating 52. Then, the center wavelength offset of reflected light of the first Bragg grating 51 is used to compensate the second Bragg grating 52, so that the size of the vibration signal can be calculated. Therefore, the embodiment can measure the size of the temperature and the vibration signal in the environment at the same time.

[0046] Specifically, in the embodiment, the hollow core optical fiber 53 in the sensing optical fiber 5 is fixed in the second optical fiber groove 210 on the packaging base 1 by high-temperature inorganic glue.

[0047] Further, as shown in the figure, Figure 4 In the embodiment, the packaging base 1 and the packaging cover plate 2 are tightly connected by spot welding.

[0048] Further, as shown in the figure, Figure 4 In the embodiment, the high-temperature-resistant optical fiber thermo-acoustic-vibration three-parameter sensor further includes a fiber armored tube 4, which is arranged in the first through hole 28 and used for protecting the sensing optical fiber 5.

[0049] Further, as shown in the figure, Figure 4 The packaging base 1 is provided with a first threaded hole 22 perpendicular to the first through hole 28, and the first threaded hole 22 is used to arrange a screw to fix the fiber armored tube 4.

[0050] Further, as shown in the figure, Figure 3 The packaging base 1 is provided with a second threaded hole 21 at the bottom, and the second threaded hole 21 is used to arrange a screw to realize fixed connection of the sensor and a measured object.

[0051] Specifically, in the embodiment, the materials of the sensitive diaphragm 3 and the sensing optical fiber 5 are quartz, and the materials of the packaging base 1 and the packaging cover plate 2 are stainless steel.

[0052] In addition, the assembling method of the high-temperature-resistant optical fiber thermo-acoustic-vibration three-parameter sensor includes the following steps:

[0053] Step S1: evenly apply high-temperature inorganic glue between the sensitive diaphragm groove 26 and the sensitive diaphragm 3, place the sensitive diaphragm 3 in the sensitive diaphragm groove 26, and use an oven to bake and solidify the high-temperature inorganic glue;

[0054] Step S2: evenly apply high-temperature inorganic glue using the full-pasting method at the positions where the sensing optical fiber 5 contacts the packaging base 1 and the quartz sensitive diaphragm 3, place the sensing optical fiber 5 on the packaging base 1 and the sensitive diaphragm 3, and use an oven to bake and solidify the high-temperature inorganic glue;

[0055] Step S3: pass the fiber armor tube 4 outside the sensing optical fiber 5 and into the first through hole 28 of the packaging base 1, and use M2 screws to fixedly connect the fiber armor tube 4 and the packaging base 1.

[0056] Step S4: use a spot welding machine to fixedly connect the packaging cover plate 2 and the packaging base 1 around.

[0057] In the embodiment, the sensing optical fiber 5 is internally engraved with a first Bragg grating 51 with a center wavelength of 1545 nm and a second Bragg grating 52 with a center wavelength of 1550 nm, the tail end of the sensing optical fiber 5 is fused with the hollow core optical fiber 53 using a fiber fusion machine, and a section of sensing optical fiber is fused behind the hollow core optical fiber 53 to form a Fabry-Perot resonant cavity. When the light output by the amplified spontaneous emission light source is sent into the sensing optical fiber 5 through the circulator, the reflected light generated in the sensing optical fiber 5 enters the spectrometer through the circulator, and the reflected spectrum of the sensing optical fiber 5 is detected by the spectrometer, as shown in FIG. 6, the obtained reflected spectrum includes the reflection peaks of the first Bragg grating 51 and the second Bragg grating 52, and the temperature and vibration signals can be demodulated respectively through the center drift of the two reflection peaks, and the noise signal can also be demodulated through the change of the free spectral range of the reflected spectrum, so that the simultaneous measurement of thermal-acoustic-vibration parameters in a high-temperature environment can be realized. Figure 7

[0058] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement to part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.​

Claims

1. A high-temperature-resistant optical fiber thermo-acoustic-vibration tri-parameter sensor, characterized in that, The application relates to a packaging structure of a sensor, which comprises the following parts: a packaging base (1) and a packaging cover plate (2), the packaging base (1) is internally provided with a first cavity (24); the packaging cover plate (2) is arranged above the packaging base (1) and is used for packaging the first cavity (24); first and second through holes (28 and 25) are arranged at two ends of the packaging base (1) and are communicated with the first cavity (24); a sensitive diaphragm groove (26) for placing a sensitive diaphragm (3) is arranged on the bottom surface of the first cavity (24), and a second cavity (23) is arranged at the bottom of the sensitive diaphragm groove (26); the two ends of the sensitive diaphragm (3) are fixedly arranged in the sensitive diaphragm groove (26), and the first cavity (24) and the second cavity (23) form a vibration space of the sensitive diaphragm (3); a sensing optical fiber (5) is fixedly arranged at the bottom of the first cavity (24) in the packaging base (1), the tail end of the sensing optical fiber (5) is arranged in the second through hole (25), the other end of the sensing optical fiber (5) extends to the outside of the packaging base (1) through the first through hole (28) after passing above the sensitive diaphragm (3); the sensing optical fiber (5) is provided with first and second Bragg gratings (51 and 52) with different central wavelengths, the first Bragg grating (51) is fixed at the bottom of the first cavity (24), and the second Bragg grating (52) is fixed on the sensitive diaphragm (3); a hollow core optical fiber (53) is arranged on one side of the sensing optical fiber (5) close to the second through hole (25), the hollow core optical fiber (53) is provided with a punching area (54) which is transversely arranged in the hollow core area of the optical fiber, and the end faces of the sensing optical fiber (5) and the hollow core optical fiber (53) adjacent to the two ends form a Fabry-Perot resonant cavity for measuring sound signals, and the first and second Bragg gratings (51 and 52) are respectively used for measuring temperature signals and vibration signals. 2.The high-temperature-resistant optical fiber thermo-acoustic-vibration tri-parameter sensor according to claim 1, wherein The sensitive diaphragm (3) is in the shape of a cantilever beam and comprises triangular supports (31) arranged at two sides and a cantilever beam (32) arranged at the center; the triangular supports (31) are arranged in the sensitive diaphragm groove (26), and the second cavity (23) is arranged below the cantilever beam (32). 3.The high-temperature-resistant optical fiber thermo-acoustic-vibration tri-parameter sensor according to claim 1, wherein The sensitive diaphragm (3) is fixed on the bottom surface of the sensitive diaphragm groove (26) by high-temperature inorganic glue.

4. The high-temperature resistant optical fiber thermo-acoustic-vibration tri-parameter sensor according to claim 1, characterized in that, The bottom of the first cavity (24) is further provided with first and second optical fiber grooves (27 and 210), and the first and second optical fiber grooves (27 and 210) are respectively arranged at two sides of the sensitive diaphragm groove (26) and are used for arranging the sensing optical fiber (5).

5. The high-temperature optical fiber thermo-acoustic-vibration tri-parameter sensor according to claim 1, characterized in that, A cover plate groove (29) is further arranged above the packaging base (1), the cover plate groove (29) is matched with the shape of the packaging cover plate (2) and is used for placing the packaging cover plate (2).

6. The high-temperature optical fiber thermo-acoustic-vibration tri-parameter sensor according to claim 1, characterized in that, The packaging structure further comprises a fiber armored tube (4), the fiber armored tube (4) is arranged in the first through hole (28) and is used for protecting the sensing optical fiber (5).

7. The high-temperature optical fiber thermo-acoustic-vibrational tri-parameter sensor according to claim 6, characterized in that, A first threaded hole (22) is arranged on the packaging base (1) and is perpendicular to the first through hole (28), and the first threaded hole (22) is used for arranging a screw to fix the fiber armored tube (4).

8. The high-temperature optical fiber thermo-acoustic-vibrational tri-parameter sensor according to claim 6, characterized in that, A second threaded hole (21) is arranged at the bottom of the packaging base (1) and is used for arranging a screw to fix the sensor.

9. The high-temperature optical fiber thermo-acoustic-vibrational tri-parameter sensor according to claim 1, characterized in that, The material of the sensitive diaphragm (3) and the sensing optical fiber (5) is quartz, and the material of the packaging base (1) and the packaging cover plate (2) is stainless steel.

10. The high-temperature resistant optical fiber thermo-acoustic-vibration tri-parameter sensor according to claim 1, characterized in that, The assembling method comprises the following steps: Step S1: uniformly applying high-temperature inorganic glue between the sensitive diaphragm groove (26) and the sensitive diaphragm (3), placing the sensitive diaphragm (3) in the sensitive diaphragm groove (26), and using an oven to bake and solidify the high-temperature inorganic glue; Step S2: uniformly applying high-temperature inorganic glue at the position where the sensing optical fiber (5) contacts the packaging base (1) and the quartz sensitive diaphragm (3), placing the sensing optical fiber (5) on the packaging base (1) and the sensitive diaphragm (3), and using an oven to bake and solidify the high-temperature inorganic glue; Step S3: threading the fiber armor tube (4) outside the sensing optical fiber (5) and into the first through hole (28) of the packaging base (1), and using a screw to fixedly connect the fiber armor tube (4) and the packaging base (1); Step S4: using a spot welding machine to fixedly connect the packaging cover plate (2) and the packaging base (1) around.

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