Manufacturing method of optical fiber Fabry-Perot sensor

Abstract

The invention discloses a manufacturing method of an optical fiber Fabry-Perot sensor, which can be used for manufacturing the optical fiber Fabry-Perot sensor in batches, reducing the manufacturing difficulty, improving the consistency of the manufactured optical fiber Fabry-Perot sensor and reducing the manufacturing error. The optical fiber Fabry-Perot sensor comprises a sensor component, an insertion core and an optical fiber, the sensor component is of a cavity structure with two open ends, a membrane is arranged in the sensor component, a flange is arranged on the surface of one side of the membrane, the optical fiber penetrates through the insertion core, the insertion core is arranged on one side of the flange of the membrane, and the insertion core is partially located in the sensor component and partially located outside the sensor component. The end face of one side of the insertion core is attached to the flange, the space between the optical fiber and the diaphragm is a Fabry-Perot cavity, and the opposite surfaces of the optical fiber and the diaphragm form two reflecting surfaces of the Fabry-Perot cavity; the manufacturing method comprises the steps of designing the sensor component, manufacturing the sensor component by adopting a template sintering process, post-processing the sensor component, assembling the insertion core, the optical fiber and the sensor component and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of sensors, and in particular to a method for manufacturing an optical fiber Fabry-Perot sensor. Background Art

[0002] Fabry-Perot sensors achieve high-precision measurement of physical quantities (such as pressure, temperature, displacement, etc.) by measuring the interference of light. Due to its high sensitivity, wide measurement range and good anti-electromagnetic interference ability, it has been widely used in industry, medical treatment, environmental monitoring and other fields.

[0003] Generally, Fabry-Perot sensors can be divided into two categories: one is the fiber Fabry-Perot sensor, which combines the Fabry-Perot interferometer with fiber optic technology and uses optical fiber to transmit optical signals; fiber Fabry-Perot sensors usually have a small size and weight, suitable for measurements in complex environments; the other is the solid Fabry-Perot sensor, which is composed of optical components and is suitable for traditional laboratory environments. Solid Fabry-Perot sensors have higher stability and reliability, but they do not perform as well as fiber optic sensors in some harsh environments.

[0004] The above two single Fabry-Perot sensors perform well in many applications, but there are still some problems and challenges in applications under complex environments. Fabry-Perot sensors mainly sense changes in the cavity length and refractive index of the Fabry-Perot cavity. The cavity length and refractive index will be affected by changes in ambient temperature, resulting in measurement errors. For example, thermal expansion of the material will cause changes in the cavity length, affecting the position of the interference fringes; and Fabry-Perot sensors are very sensitive to environmental changes, such as vibration, airflow, and electromagnetic interference. High-performance fiber Fabry-Perot sensors usually involve complex manufacturing processes, low yields, and difficult to ensure product consistency. It is difficult to mass-produce them economically and efficiently, which limits the scope of application of fiber Fabry-Perot sensors. Summary of the invention

[0005] At least one of the purposes of the present invention is to provide a method for manufacturing an optical fiber Fabry-Perot sensor in order to overcome the problems existing in the above-mentioned prior art. The method can mass-produce optical fiber Fabry-Perot sensors, reduce the difficulty of production, and improve the consistency of mass-produced optical fiber Fabry-Perot sensors, thereby reducing production errors.

[0006] In order to achieve the above-mentioned purpose, the technical solution adopted by the present invention includes the following aspects.

[0007] A method for manufacturing an optical fiber Fabry-Perot sensor comprises the following steps: Step 1: Design sensor components according to measurement parameter requirements; Step 2: Using template sintering process to make sensor components; Step 3: Post-process the manufactured sensor components; Step 4: Assemble the ferrule and optical fiber; Step 5: Assemble the ferrule and sensor components.

[0008] Preferably, in step 2, the process of manufacturing the sensor component by using a template sintering process includes: Select raw materials that are suitable for the use environment and meet manufacturing requirements; Make the raw materials into uniform powder and mix different kinds of powders in proportion; Designing the template shape of the sensor component and preparing the template of the sensor component; Filling the mixed powder into a template so that the powder forms a shape of a sensor component in the template; The formed sensor component is placed in a sintering furnace for sintering; The sintered sensor components are heat treated.

[0009] Preferably, the raw material is one or more of quartz, aluminum oxide, silicon nitride, silicon oxide, zirconium oxide and boron nitride.

[0010] Preferably, the process of mixing the different types of powders in proportion to obtain uniform mixture is carried out by mechanical stirring or ball milling, and a sintering aid is added to the powders during the mixing process.

[0011] Preferably, in the process of filling the mixed powder into the template, the mixed powder is formed into the shape of the sensor component in the template by pressing or injection; during the molding process using the pressing method, the powder in the template is heated, and the molding pressure and heating temperature are controlled to increase the density of the sensor component after molding.

[0012] Preferably, before placing the formed sensor component into a sintering furnace for sintering, the sensor component is dried to remove moisture and solvent; after the sensor component is sintered and before heat treatment, the sensor component is cooled.

[0013] Preferably, the sensor component is a cavity structure with openings at both ends, a diaphragm is integrally provided in the sensor component, and a flange is integrally provided on one or both side surfaces of the diaphragm.

[0014] Preferably, in the step three, post-treatment is performed by mechanical surface treatment, chemical surface treatment or coating, so that the diaphragm surface of the sensor component forms a reflective surface on one side of the Fabry-Perot cavity.

[0015] Preferably, in the step 4, before assembling the ferrule and the optical fiber, one end of the optical fiber is polished so that the end face of one end of the optical fiber forms a reflecting surface on one side of the Fabry-Perot cavity; in the step 5, during the process of assembling the ferrule and the sensor component, the ferrule is inserted into the sensor component from the port of the sensor component, and after the end face of the ferrule and the surface of the flange are fitted together, the ferrule and the sensor component are fixed.

[0016] Preferably, in step 4, after assembling the ferrule and the optical fiber, a pressure access port is assembled on the ferrule, and then a static pressure sensor is assembled on the ferrule on one side or both sides of the diaphragm.

[0017] The present invention also provides an optical fiber Fabry-Perot sensor, which is manufactured by the aforementioned manufacturing method of the optical fiber Fabry-Perot sensor.

[0018] In summary, due to the adoption of the above technical solution, the present invention has at least the following beneficial effects: The manufacturing method of the fiber optic Fabry-Perot sensor of the present invention simplifies the process flow, can manufacture the fiber optic Fabry-Perot sensor in batches and on a large scale, and reduce the unit production cost. Compared with other processing methods, the manufacturing method of the present invention can reduce material loss and improve material utilization. In addition, the manufacturing method of the present invention reduces the manufacturing error of the batch-produced fiber optic Fabry-Perot sensors, improves the consistency and sensitivity between the fiber optic Fabry-Perot sensors, and improves the monitoring accuracy and service life when monitoring environmental pressure. The manufactured fiber optic Fabry-Perot sensor has stable physical and chemical properties, good seismic resistance and impact resistance, performs well in a dynamic environment, and has good stability.

[0019] The sensor component of the optical fiber Fabry-Perot sensor of the present invention is manufactured by a templated sintering process. Through the sintering process, powdered material particles are combined with each other to form a dense structure, which significantly improves the mechanical strength and hardness. The sensor component has good stability in high temperature and corrosive environments and is suitable for working under harsh conditions.

[0020] The manufacturing method of the optical fiber Fabry-Perot sensor of the present invention can meet the design requirements of different optical fiber Fabry-Perot sensors, and can manufacture sensor components with complex geometric shapes and multiple sizes, thereby improving the manufacturing flexibility; by controlling the sintering parameters, sensor components with high dimensional accuracy and surface smoothness can be obtained, thereby reducing subsequent processing steps. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 Schematic diagram of the structure of an optical fiber Fabry-Perot sensor according to an exemplary embodiment of the present invention.

[0022] Figure 2 It is a schematic structural diagram of an optical fiber Fabry-Perot sensor according to another exemplary embodiment of the present invention.

[0023] Figure 3 It is a flow chart of manufacturing the optical fiber Fabry-Perot sensor according to an exemplary embodiment of the present invention.

[0024] Figure 4 Schematic diagram of a fiber optic Fabry-Perot sensing system according to an exemplary embodiment of the present invention.

[0025] Figure 5 It is a schematic diagram of a fiber optic Fabry-Perot sensing system according to another exemplary embodiment of the present invention.

[0026] Markings in the figure: 1-sensor component, 2-ferrule, 3-optical fiber, 4-pressure access port, 5-static pressure sensor. DETAILED DESCRIPTION

[0027] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments to make the purpose, technical solutions and advantages of the present invention more clearly understood. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0028] Figure 1 An optical fiber Fabry-Perot sensor of an exemplary embodiment of the present invention is shown, and the optical fiber Fabry-Perot sensor comprises: a sensor component 1, a core 2 and an optical fiber 3. The sensor component 1 is a cavity structure with openings at both ends, and its overall shape is cylindrical. A diaphragm 100 is integrally provided in the sensor component 1, and the diaphragm 100 is perpendicular to the sensor component 1. A flange 101 is integrally provided on one side surface of the diaphragm 100. The optical fiber 3 passes through the core 2, and the core 2 and the optical fiber 3 are embedded in the sensor component 1 from one end of the sensor component 1. One side end face of the core 2 is fitted with the flange 101. The space between the optical fiber 3 and the diaphragm 100 is a Fabry-Perot cavity, and the opposing surfaces of the optical fiber 3 and the diaphragm 100 constitute two reflection surfaces of the Fabry-Perot cavity.

[0029] After the optical fiber 3 passes through the ferrule 2 , its end face is flush with the end face of the ferrule 2 . After the end face of the ferrule 2 fits the surface of the flange 101 , the length of the Fabry-Perot cavity is consistent with the length of the flange 101 .

[0030] In the implementation process, multiple flanges 101 can be evenly arranged along the circumference of the diaphragm 100, and the multiple flanges 101 are arranged close to or in contact with the edge of the diaphragm 100. Alternatively, an annular flange 101 can be arranged along the circumference of the diaphragm 100, and the edge of the annular flange 101 is arranged close to or in contact with the edge of the diaphragm 100. The diaphragm 100 can be arranged in the middle of the sensor component 1, or near one end of the sensor component 1, and its specific position is arranged according to actual needs.

[0031] During the application process, flanges 101 can be respectively provided on the opposite surfaces of the diaphragm 100 according to the detection requirements (refer to Figure 2), the lengths of the flanges 101 on both sides of the diaphragm 100 are equal; after the ferrule 2 and the optical fiber 3 are respectively embedded from both ends of the sensor component 1, the end faces of the ferrule 2 on both sides of the diaphragm 100 are respectively fitted with the surface of the flange 101, and the end faces of the optical fiber 3 on both sides of the diaphragm 100 respectively form the reflection surface of the Fabry-Perot cavity with the surface of the opposite diaphragm 100. In the absence of the effect of external physical quantities, the cavity lengths of the Fabry-Perot cavities on both sides of the diaphragm 100 are equal. Pressure inlet holes are also provided on the ferrules 2 on both sides of the diaphragm 100, and the pressure access port 4 passes through the ferrule 2 through the pressure inlet holes. Sensor access holes are also provided on the ferrules 2 on both sides or one side of the diaphragm 100, and the static pressure sensor 5 passes through the ferrule 2 through the sensor access hole to perform static pressure calibration and multi-parameter measurement.

[0032] The optical fibers 3 on both sides of the diaphragm 100 are coaxially arranged, and the pressure access port 4 is coaxially arranged. In the axial direction of the diaphragm 100, the optical fiber 3 can be arranged at the center of the diaphragm 100, or at other positions of the diaphragm 100. The sensor component 1 can be a rectangular cavity, a circular cavity, or a cavity structure of other shapes. The shape of the diaphragm 100 is determined according to the cavity shape of the sensor component 1, such as a rectangle, a circle, or other shapes. From the diaphragm 100 to the port direction of the sensor component 1, the internal width of the sensor component 1 is uniform or gradually increases.

[0033] Figure 3 A method for manufacturing an optical fiber Fabry-Perot sensor according to an exemplary embodiment of the present invention is shown, and the manufacturing method comprises the following steps: Step 1: Design sensor component 1 according to measurement parameter requirements; Step 2: Using a template sintering process to manufacture the sensor component 1; Step 3: post-processing the manufactured sensor component 1; Step 4: Assemble the ferrule 2 and the optical fiber 3; Step 5: Assemble the ferrule 2 and the sensor component 1.

[0034] In step 1, the measurement parameter may be a single physical quantity (such as static pressure) or multiple physical quantities (such as differential pressure). Depending on the measurement parameters, a sensor component 1 may be designed for static pressure or differential pressure measurement.

[0035] In step 2, the specific process of using the template sintering process to make the sensor component 1 includes: Select raw materials that are suitable for the use environment and meet the manufacturing requirements based on the material properties; the raw materials can be one or more of quartz, aluminum oxide, silicon nitride, silicon oxide, zirconium oxide or boron nitride.

[0036] The raw materials are made into uniform powder, and the powder is screened and graded to ensure that the powder particles are uniform in size, so that the powder particle size distribution meets the requirements and the pores of the raw materials themselves are reduced, thereby avoiding defects during the sintering process.

[0037] Use mechanical stirring or ball milling to mix different types of powders in proportion and evenly, and try to minimize the pores generated during the mixing process; during the mixing process, powders of different particle sizes of the same material can be mixed according to the design requirements of different sensors, or powders of the same particle size can be selected from different materials for mixing. For example, among quartz, aluminum oxide, silicon nitride, silicon oxide, zirconium oxide and boron nitride, select two or more materials, and mix the powders of the same particle size in the selected materials evenly. During the mixing process, sintering aids can also be added to improve the gas flow and uniformity during the sintering process and reduce sintering pores and defects. Sintering aids include oxide sintering aids, non-oxide sintering aids, composite solvent sintering aids, antioxidants, metals, etc. The specific types and addition ratios are determined according to the types of raw materials and the required amount of raw materials.

[0038] The shape of the template of the sensor component 1 is designed, and the template of the sensor component 1 is prepared by 3D printing, computer numerical control machining or other methods; the material of the template is determined according to the raw material of the sensor component 1 and the sintering temperature.

[0039] The mixed powder is filled into the template, and the mixed powder is formed into the shape of the sensor component 1 in the template by pressing, injection or other molding methods; during the molding process using the pressing method, the powder in the template is heated, and the molding pressure and heating temperature are controlled to increase the density of the sensor component 1 after molding.

[0040] The preliminarily formed sensor component 1 is dried to remove moisture and solvent to prevent cracks from being generated during the subsequent sintering process. The drying time and temperature are adjusted according to the properties of the raw materials. Before drying, whether to demold is determined based on whether the template material and structure are conducive to moisture evaporation and drying.

[0041] The sensor component 1 is placed in a sintering furnace (before being placed in the sintering furnace, the sensor component is demolded), and the heating rate is controlled according to a predetermined temperature gradient (e.g., the temperature rises by 5 to 10 degrees Celsius per minute). After being heated to the sintering temperature (the sintering temperature is determined according to the melting point or phase change temperature of the raw material), it is kept at the sintering temperature for a certain period of time (the holding time is determined according to the raw material, the sintering temperature and the type of sintering furnace, for example, when the raw material is metal, the holding time is 0.5 to 1 hour, and when the raw material is ceramic, the holding time is 1 to 2 hours). The powder particles are sintered, and the particles are reorganized. The particles are combined with each other to form a dense solid material. During the sintering process, the interaction force between particles (van der Waals force, chemical bonding, etc.) promotes the bonding between particles. During the sintering process, the density can be effectively improved and the porosity can be reduced by controlling the sintering temperature and time. After sintering, the temperature is slowly cooled according to the predetermined temperature gradient (such as 5-10 degrees Celsius per minute). The cooling rate is controlled by the temperature control system of the cooling furnace, hot air or nitrogen cooling, or by setting a specific cooling curve to prevent cracks caused by thermal stress in the material. The thermal stress is expressed as:

[0042] in, σ For thermal stress, E is the Young's modulus of the material, α is the coefficient of thermal expansion, △T For temperature changes.

[0043] The cooled sensor component 1 is heat treated by annealing, normalizing, quenching, tempering, etc. to improve the microstructure and mechanical properties of the material.

[0044] Taking aluminum oxide as the raw material as an example, the process of making the sensor component 1 by using the template sintering process is explained: aluminum oxide is made into uniform aluminum oxide powder, and after screening and grading the aluminum oxide powder, aluminum oxide powders with a particle size of 5um and 10um are selected by mechanical stirring or ball milling, and they are evenly mixed in a ratio of 80%:20%; about 2% (the specific ratio is adjusted according to equipment parameters and actual conditions) of boric acid sintering aid is added to the mixed aluminum oxide powder and mixed evenly, and then the mixture is sintered with reference to Figure 1The sensor component 1 shown in the figure designs the template shape of the sensor component 1, uses graphite or silicon carbide as the template material, and uses 3D printing, computer numerical control machining or other methods to prepare the template of the sensor component 1; after the template is prepared, the mixed alumina powder is filled into the template, and the mixed alumina powder is formed into the shape of the sensor component 1 in the template by pressing, injection or other molding methods, and then the preliminarily formed sensor component 1 is dried to remove moisture and solvent; after the sensor component 1 is demolded, the sensor component 1 is placed in a sintering furnace, and the heating rate is controlled to 5°C / min. After heating to 1600 degrees Celsius, it is maintained for 2 hours, and then the cooling rate is controlled to 3°C / min. After the sensor component is cooled, the sensor component 1 is heat treated by annealing to improve the microstructure and mechanical properties of the sensor component 1 material.

[0045] In step three, when the manufactured sensor component 1 is post-processed, mechanical surface treatment, chemical surface treatment or coating can be used to make the surface of the diaphragm 100 of the sensor component 1 have a certain reflectivity, forming a reflective surface on one side of the Fabry-Perot cavity, and making the surface of the flange 101 smooth, so that the end face of the core 2 and the surface of the flange 101 fit closely. Post-processing can also improve the material properties and surface quality of the sensor component 1, thereby improving the sensing performance and durability of the optical fiber Fabry-Perot sensor.

[0046] In step four, before assembling the ferrule 2 and the optical fiber 3, one end of the optical fiber 3 is polished so that the end face of one end of the optical fiber 3 forms a reflecting surface on one side of the Fabry-Perot cavity; after the optical fiber 3 passes through the ferrule 2, it is preferably made that the polished end face of the optical fiber 3 is flush with the end face of the ferrule 2, and then the optical fiber 3 and the ferrule 2 are cured. After curing, in step five, the polished end of the optical fiber 3 is made to face the flange 101, and the optical fiber 3 and the ferrule 2 are inserted into the sensor component 1 together. After the end face of the ferrule 2 fits the flange 101, the ferrule 2 and the sensor component 1 are fixed. After fixation, the space between the end face of the optical fiber 3 and the surface of the diaphragm 100 forms a Fabry-Perot cavity.

[0047] In step four, when the optical fiber 3 passes through the ferrule 2, the optical fiber 3 can be inserted along the central axis of the ferrule 2 so that the central axis of the optical fiber 3 is coaxial with the central axis of the ferrule 2; the optical fiber 3 can also be inserted deviating from the central axis of the ferrule 2 so that the central axis of the optical fiber 3 is parallel to the central axis of the ferrule 2. The specific insertion method is determined according to the measurement requirements.

[0048] When manufacturing an optical fiber Fabry-Perot sensor for measuring static pressure, in the process of designing the sensor component 1 in the aforementioned step one, the diaphragm 100 is arranged close to one end port of the sensor component 1; in the process of assembling the optical fiber 3 and the ferrule 2 in step four, the optical fiber 3 is preferably inserted along the central axis of the ferrule 2 so that the central axis of the optical fiber 3 is coaxial with the central axis of the ferrule 2; in step five, after the ferrule 2 is inserted into the sensor component 1, the ferrule 2 is partially located inside the sensor component 1 and partially located outside the sensor component 1, and the end face of the ferrule 2 in the sensor component 1 is in contact with the surface of the flange 101.

[0049] After the transmission light is transmitted to the Fabry-Perot cavity via the optical fiber 3, it is reflected by the end face of the optical fiber 3 and the surface of the diaphragm 100 to form two beams of reflected light. The two beams of reflected light are transmitted to the demodulation system (such as an optical fiber signal demodulator, etc.) via the optical fiber 3 for signal demodulation. Figure 4 As shown, when the diaphragm 100 is deformed under pressure, the cavity length of the Fabry-Perot cavity formed by the optical fiber 3 and the diaphragm 100 will change, resulting in a change in the optical path difference. By monitoring the change in the optical signal, the external physical quantity can be monitored.

[0050] When manufacturing an optical fiber Fabry-Perot sensor for measuring differential pressure, in the process of designing the sensor component 1 in the aforementioned step 1, the diaphragm 100 is arranged close to the middle of the sensor component 1 or the diaphragm 100 is located in the middle of the sensor component 1, and flanges 101 are arranged on both sides of the diaphragm 100; in the process of assembling the optical fiber 3 and the ferrule 2 in step 4, the optical fiber 3 is preferably inserted along the central axis of the ferrule 2, so that the central axis of the optical fiber 3 is coaxial with the central axis of the ferrule 2; after the optical fiber 3 and the ferrule 2 are assembled, the pressure access port 4 is assembled on the ferrule 2, and the pressure access port 4 and the ferrule 2 are fixed, and the pressure access port 4 is eccentric The optical fiber 3 and the pressure access port 4 are arranged so that the central axis thereof is parallel to the central axis of the optical fiber 3; after the optical fiber 3 and the pressure access port 4 are assembled with the ferrule 2, a static pressure sensor 5 is assembled on one or both of the ferrules 2, and after the static pressure sensor 5 passes through the ferrule 2 through the sensor access hole, the static pressure sensor 5 is fixed on the ferrule 2, and the central axis of the static pressure sensor 5 is parallel to the central axis of the optical fiber 3; the assembly order of the optical fiber 3, the pressure access port 4, and the static pressure sensor 5 on the ferrule 2 can be changed; when assembling the static pressure sensor 5, the aforementioned optical fiber Fabry-Perot sensor for measuring static pressure can be used (the external dimensions of the optical fiber Fabry-Perot sensor can be adjusted according to actual needs, Figure 1 , Figure 2 The details are shown by enlarged schematic diagrams), and other static pressure sensors can also be used. Step 5 After the ferrule 2 is inserted into the sensor component 1, the ferrules 2 on both sides of the diaphragm 100 are partially located inside the sensor component 1 and partially located outside the sensor component 1. The end face of the ferrule 2 in the sensor component 1 is in contact with the surface of the flange 101, and the optical fibers 3 and the pressure access ports 4 on both sides of the diaphragm 100 are coaxial.

[0051] After the transmission light on both sides of the diaphragm 100 is transmitted to the Fabry-Perot cavities on both sides of the diaphragm 100 through the optical fiber 3, it is reflected by the end face of the optical fiber 3 and the surface of the diaphragm 100 to form two beams of reflected light. The two beams of reflected light are transmitted to the demodulation system (such as an optical fiber signal demodulator, etc.) through the optical fiber 3 for signal demodulation. Figure 5 When different pressures are introduced into the Fabry-Perot cavities on both sides of the diaphragm 100 through the access port 4, pressure differences are generated in the Fabry-Perot cavities on both sides of the diaphragm 100, causing the diaphragm 100 to deform under pressure, resulting in opposite changes in the lengths of the Fabry-Perot cavities on both sides of the diaphragm 100, that is, the length of the cavity on the side with greater pressure becomes longer, and the length of the cavity on the side with less pressure becomes shorter. By monitoring the changes in the optical signal, the monitoring of external physical quantities can be achieved; at the same time, the static pressure can be detected by the static pressure sensor 5, and static pressure calibration and multi-parameter measurement can be achieved.

[0052] The parameters of one of the optical fiber Fabry-Perot sensors prepared by the aforementioned method are as follows: the thickness of the diaphragm 100 is 0.1-3 mm, the thickness of the flange 101 is consistent with the thickness of the diaphragm 100, the length of the Fabry-Perot cavity is consistent with the length of the flange 101 (one of the lengths is 200 um), the height of the sensor component 1 is not more than 30 mm, and the wall thickness is not more than 5 mm; the cavity length of the optical fiber Fabry-Perot sensor prepared by the aforementioned method is determined by the thickness of the flange 101. When the optical fiber Fabry-Perot sensors are mass-produced, the consistency of the optical fiber Fabry-Perot sensors can be improved by controlling the thickness of the flange 101, the manufacturing error can be reduced, and the yield rate can be improved. The physical and chemical properties of the manufactured optical fiber Fabry-Perot sensors are stable, and they have good seismic resistance and impact resistance, and are suitable for working in harsh environments.

[0053] The above is only a detailed description of the specific implementation of the present invention, rather than a limitation of the present invention. Various substitutions, modifications and improvements made by those skilled in the relevant art without departing from the principle and scope of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for manufacturing an optical fiber Fabry-Perot sensor, characterized in that: The following steps are involved: Step 1: Design sensor components according to measurement parameter requirements; Step 2: Using template sintering process to make sensor components; Step 3: Post-process the manufactured sensor components; Step 4: Assemble the ferrule and optical fiber; Step 5: Assemble the ferrule and sensor components.

2. The method for manufacturing the optical fiber Fabry-Perot sensor according to claim 1, characterized in that: In the step 2, the process of manufacturing the sensor component by using the template sintering process includes: Select raw materials that are suitable for the use environment and meet manufacturing requirements; Make the raw materials into uniform powder and mix different kinds of powders in proportion; Designing the template shape of the sensor component and preparing the template of the sensor component; Filling the mixed powder into a template so that the powder forms a shape of a sensor component in the template; The formed sensor component is placed in a sintering furnace for sintering; The sintered sensor components are heat treated.

3. The method for manufacturing the optical fiber Fabry-Perot sensor according to claim 2, characterized in that: The raw material is one or more of quartz, aluminum oxide, silicon nitride, silicon oxide, zirconium oxide and boron nitride.

4. The method for manufacturing the optical fiber Fabry-Perot sensor according to claim 2, characterized in that: The process of mixing different types of powders in proportion and making them uniform is carried out by mechanical stirring or ball milling. During the mixing process, a sintering aid is added to the powders.

5. The method for manufacturing the optical fiber Fabry-Perot sensor according to claim 2, characterized in that: In the process of filling the mixed powder into the template, the mixed powder is formed into the shape of the sensor component in the template by pressing or injection; in the molding process using the pressing method, the powder in the template is heated, and the molding pressure and heating temperature are controlled to improve the density of the sensor component after molding.

6. The method for manufacturing the optical fiber Fabry-Perot sensor according to claim 2, characterized in that: Before the formed sensor component is placed in a sintering furnace for sintering, the sensor component is dried to remove moisture and solvent; after the sensor component is sintered and before heat treatment, the sensor component is cooled.

7. The method for manufacturing the optical fiber Fabry-Perot sensor according to any one of claims 1 to 6, characterized in that: The sensor component is a cavity structure with openings at both ends. A diaphragm is integrally arranged in the sensor component, and flanges are integrally arranged on one or both sides of the surface of the diaphragm.

8. The method for manufacturing the optical fiber Fabry-Perot sensor according to claim 7, characterized in that: In the step three, post-treatment is performed by mechanical surface treatment, chemical surface treatment or coating, so that the diaphragm surface of the sensor component forms a reflective surface on one side of the Fabry-Perot cavity.

9. The method for manufacturing the optical fiber Fabry-Perot sensor according to claim 7, characterized in that: In the step 4, before assembling the ferrule and the optical fiber, one end of the optical fiber is polished so that the end face of the optical fiber forms a reflection surface on one side of the Fabry-Perot cavity; In the step 5, during the assembly of the ferrule and the sensor component, the ferrule is inserted into the sensor component from the port of the sensor component, and after the end face of the ferrule and the surface of the flange are fitted together, the ferrule and the sensor component are fixed.

10. The method for manufacturing the optical fiber Fabry-Perot sensor according to claim 7, characterized in that: In the step 4, after assembling the ferrule and the optical fiber, a pressure access port is assembled on the ferrule, and then a static pressure sensor is assembled on the ferrule on one side or both sides of the diaphragm.

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