One-dimensional acceleration optical fiber sensor based on F-P cavity interference theory and magnetic suspension technology, preparation method and application

Abstract

The invention provides a one-dimensional acceleration optical fiber sensor based on an F-P cavity interference theory and a magnetic suspension technology and a preparation method and application thereof.The one-dimensional acceleration optical fiber sensor comprises a shell, an upper cover and a lower cover are arranged at the upper end and the lower end of the shell respectively, a first cavity is formed in the shell, and a suspension shell is arranged in the first cavity; a magnet is arranged below the suspension shell and connected with the lower cover, a first through hole is formed in the suspension shell, and an optical fiber is arranged in the first through hole; the bottom end of the optical fiber is provided with a first high-reflective film, and a second high-reflective film is arranged below the first high-reflective film. According to the one-dimensional acceleration optical fiber sensor based on the F-P cavity interference theory and the magnetic suspension technology, the preparation method and the application, the size is smaller, the one-dimensional acceleration optical fiber sensor can be more conveniently attached to a measured object, and measurement in one dimension direction is efficiently achieved.

Description

Technical Field

[0001] The present invention relates to the field of acoustic field acceleration measurement, and in particular to a one-dimensional acceleration optical fiber sensor based on FP cavity interference theory and magnetic suspension technology, a preparation method and an application thereof. Background Art

[0002] In recent years, fiber optic accelerometers have shown great application potential in many fields due to their high precision, anti-electromagnetic interference, high temperature resistance and corrosion resistance. With the continuous advancement of technology, fiber optic accelerometers will become more and more miniaturized, intelligent, and integrated, and play an increasingly important role in more fields. In the future, we can foresee that fiber optic accelerometers will play a more important role in aerospace, earthquake monitoring, intelligent transportation, industrial monitoring, medical health and other fields. In view of this, we designed a new one-dimensional acceleration fiber optic sensor based on FP cavity interference theory and magnetic levitation technology. The magnetic levitation shell we designed is cleverly combined with the optical fiber reflection end face to construct a fiber optic mirror interference cavity. Using the principle of inertia, we can measure the acceleration of the object. Summary of the invention

[0003] The purpose of the present invention is to provide a one-dimensional acceleration fiber optic sensor, preparation method and application based on FP cavity interference theory and magnetic levitation technology. The magnetic levitation shell is cleverly combined with the optical fiber reflection end face to construct an optical fiber mirror interference cavity. Using the inertia principle, we can measure the acceleration of the object. The acceleration fiber optic sensor designed in this paper has the advantages of small size, low cost, and easy large-scale production. It can be attached to the object to be measured to measure the acceleration value of one dimension.

[0004] To achieve the above-mentioned object, the present invention provides a one-dimensional acceleration optical fiber sensor based on FP cavity interference theory and magnetic suspension technology, comprising a shell, an upper cover and a lower cover are respectively arranged at the upper and lower ends of the shell, a first cavity is arranged in the shell, a suspension shell is arranged in the first cavity, a magnet is arranged below the suspension shell and connected to the lower cover, a first through hole is arranged on the suspension shell, and an optical fiber is arranged in the first through hole; A first high-reflection film is arranged at the bottom end of the optical fiber, and a second high-reflection film is arranged below the first high-reflection film.

[0005] Preferably, a second cavity is provided in the suspension housing, and the bottom end of the inner wall of the second cavity is connected to the second high-reflection film; and a distance is provided between the first high-reflection film and the second high-reflection film.

[0006] Preferably, a first protrusion is provided on the top of the outer wall of the suspension housing, a second through hole is provided on the top, the second through hole is coaxial with the first through hole, and the optical fiber is located in the second through hole.

[0007] Preferably, a third through hole is provided on the upper cover, an optical fiber fixing core is provided in the third through hole, the optical fiber fixing core is connected to the upper cover, and the optical fiber fixing core fixes the optical fiber.

[0008] Preferably, the top end of the optical fiber fixing core may be further provided with a second protrusion located outside the top end of the upper cover, and the plane area of ​​the second protrusion is larger than the plane area of ​​the third through hole.

[0009] Preferably, a first flange and a second flange are provided on the outer shell at the upper and lower ends of the outer shell, and the first flange and the second flange are connected to the upper cover and the lower cover respectively.

[0010] Preferably, the suspension housing is in a suspended state, and the suspension housing, the first protrusion and the optical fiber are not in direct contact.

[0011] Preferably, the thickness of the suspension shell is in the range of 0.1 to 5 mm.

[0012] A method for preparing a one-dimensional acceleration optical fiber sensor based on FP cavity interference theory and magnetic levitation technology comprises the following steps: (1) Coating a high reflectivity film on the bottom surface of the suspended housing and the end face of the optical fiber; (2) Fix the base, magnet, suspension housing, ceramic pin, and optical fiber in sequence, control the distance, and leave part of the optical fiber at the upper end; (3) The stripped and cut single-mode optical fiber is fused with the jumper cable so that it can be connected to the demodulation system to measure the acceleration of the acoustic field.

[0013] The invention discloses an application of a one-dimensional acceleration optical fiber sensor based on FP cavity interference theory and magnetic suspension technology in an acceleration test device.

[0014] Therefore, the present invention adopts the above-mentioned one-dimensional acceleration optical fiber sensor based on FP cavity interference theory and magnetic levitation technology, preparation method and application, and the technical effects are as follows: (1) The acceleration fiber sensor has low production cost and simple structure; (2) Fiber optic sensors have good sensitivity, high accuracy and can adapt to various harsh environments; (3) The one-dimensional acceleration fiber optic sensor based on FP cavity interference theory and magnetic levitation technology is smaller in size and can be more conveniently attached to the object being measured, thus efficiently realizing measurement in one dimension. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of a one-dimensional acceleration fiber optic sensor based on FP cavity interference theory and magnetic levitation technology; Figure 2It is a schematic diagram of the first structure and the first situation of the connection method of the upper cover and the optical fiber fixing core; Figure 3 A schematic diagram of the first structure and the second connection method of the upper cover and the optical fiber fixing core; Figure 4 It is a schematic diagram of the second structure and connection method of the upper cover and the optical fiber fixing core; Figure 5 for Figure 2 A partial enlarged view of the D area in the middle.

[0016] Reference numerals 1. Outer shell; 2. Upper cover; 3. Lower cover; 4. Suspended outer shell; 5. Magnet; 6. Optical fiber; 7. First high-reflection film; 8. Second high-reflection film; 9. First protrusion; 10. Optical fiber fixing core; 11. Second protrusion; 12. First flange; 13. Second flange. DETAILED DESCRIPTION

[0017] The technical solution of the present invention is further described below through the accompanying drawings and embodiments.

[0018] Unless otherwise defined, technical or scientific terms used in the present invention shall have the common meanings understood by one having ordinary skills in the field to which the present invention belongs.

[0019] Embodiment 1 like Figure 1 As shown, the present invention provides a one-dimensional acceleration fiber 6 sensor based on FP cavity interference theory and magnetic levitation technology, a preparation method and application, including a shell 1, an upper cover 2 and a lower cover 3 are respectively arranged at the upper and lower ends of the shell 1, and a first flange 12 and a second flange 13 are arranged on the shell 1 at the upper and lower ends of the shell 1, and the first flange 12 and the second flange 13 are respectively connected to the upper cover 2 and the lower cover 3.

[0020] The upper cover 2 , the first flange 12 , the second flange 13 and the lower cover 3 are all provided with threaded holes, and the upper cover 2 and the first flange 12 are fixed by screws, and the lower cover 3 and the second flange 13 are fixed.

[0021] The upper cover 2 is provided with a third through hole, and an optical fiber fixing core 6 is provided in the third through hole. The optical fiber fixing core 6 is connected to the upper cover 2 , and the optical fiber fixing core 6 fixes the optical fiber 6 .

[0022] like Figure 2 and Figure 3 As shown, the first structure of the optical fiber fixing core 6 and the upper cover 2 and the connection method thereof are: The optical fiber fixing core 6 and the upper cover 2 can be connected together by integral molding, adhesive bonding or other connection methods. The optical fiber 6 is fixed to the optical fiber fixing core 6 by adhesive bonding or friction.

[0023] like Figure 4 As shown, the second structure of the optical fiber fixing core 6 and the upper cover 2 and the connection method thereof are: The top of the optical fiber fixing core 6 can also be provided with a second protrusion 11 located outside the top of the upper cover 2. The plane area of ​​the second protrusion 11 is larger than the plane area of ​​the third through hole. At this time, the optical fiber fixing core 6 is supported by the upper cover 2 to play a fixing role.

[0024] You can choose either of the two structures and their connection methods.

[0025] A first cavity is provided in the shell 1, a suspension shell 4 is provided in the first cavity, a magnet 5 is provided below the suspension shell 4 and connected to the lower cover 3, and the magnetic suspension shell 4 is made of magnetic material, so under the action of the magnet 5, the suspension shell 4 is in a suspended state.

[0026] The shape of the magnet 5 is arbitrary, as long as it matches the lower cover 3 , and the strength of the magnet 5 matches the required height of the suspension housing 4 .

[0027] The suspension housing 4 is provided with a first through hole, in which an optical fiber 6 is provided. The suspension housing 4, the first protrusion 9 and the optical fiber 6 are not in direct contact, so as to avoid the influence of friction on the measurement result.

[0028] A first protrusion 9 is provided at the top of the outer wall of the suspension housing 4, and a second through hole is provided on the top. The second through hole and the first through hole are coaxial, and the optical fiber 6 is located in the second through hole.

[0029] The first protrusion 9 is provided to prevent the optical fiber 6 from bending when the suspension housing 4 moves, thereby affecting the final measurement result.

[0030] The type of optical fiber 6 is not limited, such as anti-microbend optical fiber 6, and the loss of optical fiber 6 can be ignored.

[0031] like Figure 5 As shown, a first high-reflection film 7 is provided at the bottom end of the optical fiber 6, a second high-reflection film 8 is provided below the first high-reflection film 7, a second cavity is provided in the suspension housing 4, and the bottom end of the inner wall of the second cavity is connected to the second high-reflection film 8; a distance is provided between the first high-reflection film 7 and the second high-reflection film 8.

[0032] Due to the inertia of the suspension housing 4 , the suspension housing 4 will be displaced upward or downward in the axial direction, so that the distance between the first high reflection film 7 and the second high reflection film 8 changes, thereby measuring the axial acceleration.

[0033] The thickness of the suspension housing 4 is in the range of 0.1 to 5 mm.

[0034] A method for preparing a one-dimensional acceleration optical fiber 6 sensor based on FP cavity interference theory and magnetic levitation technology comprises the following steps: (1) coating a high reflectivity film on the bottom surface of the suspension housing 4 and the end surface of the optical fiber 6; (2) Fix the base, magnet 5, suspension housing 4, ceramic pin, and optical fiber 6 in sequence, control the distance, and leave part of the optical fiber 6 at the upper end; (3) The stripped and cut single-mode optical fiber 6 is fused with the jumper so as to be connected to the demodulation system for measuring the acceleration of the acoustic field.

[0035] The invention discloses an application of a one-dimensional acceleration optical fiber 6 sensor based on FP cavity interference theory and magnetic suspension technology in an acceleration test device.

[0036] Working principle: When the optical fiber 6 acceleration optical fiber 6 sensor is subjected to acceleration parallel to the axial direction of the suspended shell 4, due to the inertia of the suspended shell 4, the suspended shell 4 will produce an upward or downward displacement in the axial direction, causing the distance of the FP cavity to be enlarged or reduced, resulting in a phase change, and then the phase change caused by the acceleration in the sound field is obtained by demodulation to achieve the measurement of the acceleration of the sound field.

[0037] Therefore, the present invention adopts the above-mentioned one-dimensional acceleration fiber optic sensor based on FP cavity interference theory and magnetic levitation technology, preparation method and application, the magnetic levitation shell is cleverly combined with the optical fiber reflection end face to construct an optical fiber mirror interference cavity, and using the inertia principle, we can measure the acceleration of the object. The acceleration fiber optic sensor designed in this article has the advantages of small size, low cost, and easy large-scale production. It can be attached to the object to be measured to measure the acceleration value of one dimension.

[0038] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the present invention.

Claims

1. A one-dimensional acceleration optical fiber sensor based on FP cavity interference theory and magnetic levitation technology, characterized in that: The device comprises a housing, wherein an upper cover and a lower cover are respectively arranged at the upper and lower ends of the housing, a first cavity is arranged in the housing, a suspension housing is arranged in the first cavity, a magnet is arranged below the suspension housing and connected to the lower cover, a first through hole is arranged on the suspension housing, and an optical fiber is arranged in the first through hole; A first high-reflection film is arranged at the bottom end of the optical fiber, and a second high-reflection film is arranged below the first high-reflection film.

2. The one-dimensional acceleration optical fiber sensor based on FP cavity interference theory and magnetic levitation technology according to claim 1 is characterized in that: A second cavity is provided in the suspension housing, and the bottom end of the inner wall of the second cavity is connected to the second high-reflection film; a distance is provided between the first high-reflection film and the second high-reflection film.

3. The one-dimensional acceleration optical fiber sensor based on FP cavity interference theory and magnetic levitation technology according to claim 1 is characterized in that: A first protrusion is arranged on the top of the outer wall of the suspension housing, a second through hole is arranged on the top, the second through hole is coaxial with the first through hole, and the optical fiber is located in the second through hole.

4. The one-dimensional acceleration optical fiber sensor based on FP cavity interference theory and magnetic levitation technology according to claim 1, characterized in that: The upper cover is provided with a third through hole, an optical fiber fixing core is provided in the third through hole, the optical fiber fixing core is connected to the upper cover, and the optical fiber fixing core fixes the optical fiber.

5. The one-dimensional acceleration optical fiber sensor based on FP cavity interference theory and magnetic levitation technology according to claim 4 is characterized in that: The top end of the optical fiber fixing core may also be provided with a second protrusion located outside the top end of the upper cover, and the plane area of ​​the two protrusions is larger than the plane area of ​​the third through hole.

6. The one-dimensional acceleration optical fiber sensor based on FP cavity interference theory and magnetic levitation technology according to claim 1, characterized in that: The upper and lower ends of the shell are provided with a first flange and a second flange on the shell, and the first flange and the second flange are connected to the upper cover and the lower cover respectively.

7. The one-dimensional acceleration optical fiber sensor based on FP cavity interference theory and magnetic levitation technology according to claim 1, characterized in that: The suspension housing is in a suspension state, and the suspension housing, the first protrusion and the optical fiber are not in direct contact.

8. The one-dimensional acceleration optical fiber sensor based on FP cavity interference theory and magnetic levitation technology according to claim 1, characterized in that: The thickness of the suspension shell is in the range of 0.1 to 5 mm.

9. A method for preparing a one-dimensional acceleration optical fiber sensor based on FP cavity interference theory and magnetic levitation technology according to any one of claims 1 to 8, characterized in that: The following steps are involved: (1) Coating a high reflectivity film on the bottom surface of the suspended housing and the end face of the optical fiber; (2) Fix the base, magnet, suspension housing, ceramic pin, and optical fiber in sequence, control the distance, and leave part of the optical fiber at the upper end; (3) The stripped and cut single-mode optical fiber is fused with the jumper cable so that it can be connected to the demodulation system to measure the acceleration of the sound field.

10. Application of a one-dimensional acceleration optical fiber sensor based on FP cavity interference theory and magnetic levitation technology according to any one of claims 1 to 8 in an acceleration test device.

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