CN116242405A - Optical fiber Fabry-Perot sensor and manufacturing method thereof - Google Patents
Optical fiber Fabry-Perot sensor and manufacturing method thereof Download PDFInfo
- Publication number
- CN116242405A CN116242405A CN202310367870.1A CN202310367870A CN116242405A CN 116242405 A CN116242405 A CN 116242405A CN 202310367870 A CN202310367870 A CN 202310367870A CN 116242405 A CN116242405 A CN 116242405A
- Authority
- CN
- China
- Prior art keywords
- plug
- protective sleeve
- incident
- fabry
- optical fiber
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 239000013307 optical fiber Substances 0.000 title claims abstract description 49
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 31
- 230000001681 protective effect Effects 0.000 claims abstract description 131
- 238000007789 sealing Methods 0.000 claims description 26
- 230000005540 biological transmission Effects 0.000 claims description 14
- 230000007704 transition Effects 0.000 claims description 9
- 239000000835 fiber Substances 0.000 claims description 6
- 229910052594 sapphire Inorganic materials 0.000 claims description 3
- 239000010980 sapphire Substances 0.000 claims description 3
- 239000012780 transparent material Substances 0.000 claims description 3
- 230000009286 beneficial effect Effects 0.000 abstract description 2
- 230000008859 change Effects 0.000 description 8
- 238000003466 welding Methods 0.000 description 7
- 238000000227 grinding Methods 0.000 description 6
- 238000000034 method Methods 0.000 description 6
- 239000012530 fluid Substances 0.000 description 5
- 230000001276 controlling effect Effects 0.000 description 4
- 238000001514 detection method Methods 0.000 description 4
- 238000010586 diagram Methods 0.000 description 4
- 238000005259 measurement Methods 0.000 description 4
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 description 3
- 229910000831 Steel Inorganic materials 0.000 description 3
- 239000000463 material Substances 0.000 description 3
- 238000005498 polishing Methods 0.000 description 3
- 230000008569 process Effects 0.000 description 3
- 239000010959 steel Substances 0.000 description 3
- 230000000694 effects Effects 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 238000009434 installation Methods 0.000 description 2
- 238000005245 sintering Methods 0.000 description 2
- 238000010009 beating Methods 0.000 description 1
- 238000005452 bending Methods 0.000 description 1
- 230000008602 contraction Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 210000001503 joint Anatomy 0.000 description 1
- 230000013011 mating Effects 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000005457 optimization Methods 0.000 description 1
- 238000012856 packing Methods 0.000 description 1
- 239000004038 photonic crystal Substances 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
- G01D5/00—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable
- G01D5/26—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light
- G01D5/32—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light
- G01D5/34—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells
- G01D5/353—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells influencing the transmission properties of an optical fibre
- G01D5/35306—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells influencing the transmission properties of an optical fibre using an interferometer arrangement
- G01D5/35309—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells influencing the transmission properties of an optical fibre using an interferometer arrangement using multiple waves interferometer
- G01D5/35316—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells influencing the transmission properties of an optical fibre using an interferometer arrangement using multiple waves interferometer using a Bragg gratings
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
- G01D5/00—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable
- G01D5/26—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light
- G01D5/32—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light
- G01D5/34—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells
- G01D5/353—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells influencing the transmission properties of an optical fibre
- G01D5/3537—Optical fibre sensor using a particular arrangement of the optical fibre itself
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Light Guides In General And Applications Therefor (AREA)
- Length Measuring Devices By Optical Means (AREA)
Abstract
The invention discloses an optical fiber Fabry-Perot sensor and a manufacturing method thereof, wherein the optical fiber Fabry-Perot sensor comprises a protective sleeve which is integrally cylindrical, two ends of the protective sleeve are provided with mounting parts which are used for being fixed on the surface of an object to be detected, an incident plug and a reflecting plug are respectively plugged, and Fabry-Perot cavities are formed between the incident plug and the reflecting plug at intervals; the incident optical fiber is embedded in the incident plug, and one end of the reflecting plug, which faces the incident plug, is a reflecting surface; and the two end parts of the protective sleeve are respectively and hermetically connected with the incident plug and the reflecting plug. The optical fiber Fabry-Perot sensor has the advantages of ingenious structure, simple manufacturing process and the like, and the manufacturing method of the optical fiber Fabry-Perot sensor has the advantages of being beneficial to improving production efficiency, reducing production cost and the like.
Description
Technical Field
The invention relates to the technical field of optical fiber Fabry-Perot sensors, in particular to an optical fiber Fabry-Perot sensor and a manufacturing method thereof.
Background
Currently, the most widely used optical fiber strain sensor is mainly based on an optical fiber Bragg grating technology and an optical fiber Fabry-Perot interference technology. By utilizing the characteristic that the cavity length of the optical fiber Fabry-Perot sensor is sensitive to external physical quantity, the optical fiber Fabry-Perot sensor is widely applied to sensing parameters such as strain, pressure, temperature, refractive index and the like in various fields such as industry. The optical fiber Fabry-Perot sensor is classified into an intrinsic Fabry-Perot sensor and an extrinsic Fabry-Perot sensor. The extrinsic Fabry-Perot sensor is characterized in that an Fabry-Perot cavity is formed by taking an optical fiber end face and an air interface as reflecting surfaces, and the sensor has a sensing characteristic of being sensitive to a certain physical or chemical parameter. At present, the extrinsic Fabry-Perot sensor mainly welds a section of hollow optical fiber, a hollow capillary or a hollow photonic crystal optical fiber between two sections of single-mode optical fibers, or directly aligns and fixes the two sections of single-mode optical fibers by using the hollow capillary.
However, in a specific application, it is also necessary to manufacture a corresponding housing for the detection environment, and to install the above-mentioned sensor in the housing and to install the sensor at the measurement point through the housing. For example, for an optical fiber fabry-perot sensor used in a high-temperature and high-pressure environment, the fabry-perot sensor needs to be mounted on a base, sealed by a sleeve, and then mounted for use. In this way, the deformation from the deformation of the sleeve to the base is finally transmitted to the Fabry-Perot sensor, and the deformation needs to be converted for a plurality of times, so that the detection precision is affected. In addition, the sensor with the structure needs to be manufactured with the sensor body, the base and the sleeve, then assembled, the accuracy of subsequent installation needs to be ensured in the assembly process, the process flow is more, and the production efficiency is affected.
Disclosure of Invention
Aiming at the defects in the prior art, the invention aims to solve the technical problems that: how to provide an optical fiber Fabry-Perot sensor with ingenious structure, simple manufacturing process, contribution to improving production efficiency and reducing production cost and a manufacturing method thereof.
In order to solve the technical problems, the invention adopts the following technical scheme:
the optical fiber Fabry-Perot sensor is characterized by comprising a protective sleeve which is integrally cylindrical, wherein two ends of the protective sleeve are provided with mounting parts which are used for being fixed on the surface of an object to be measured, an incident plug and a reflecting plug are respectively plugged, and Fabry-Perot cavities are formed between the incident plug and the reflecting plug at intervals; the incident optical fiber is embedded in the incident plug, and one end of the reflecting plug, which faces the incident plug, is a reflecting surface; and the two end parts of the protective sleeve are respectively and hermetically connected with the incident plug and the reflecting plug.
When the device is used, the installation parts of the protective sleeves are respectively fixed on the surface of an object to be measured, once the surface of the object to be measured is deformed, the length of the protective sleeves can be changed, and the length change of the protective sleeves is embodied in the change of the length of the Fabry-Perot cavity, so that the strain can be measured. In the structure, the Fabry-Perot cavity is formed by directly utilizing the gap between the incidence plug and the reflection plug, the sensor body is not required to be manufactured by using optical fibers, and then the sensor body is assembled, and the Fabry-Perot cavity for measurement is directly formed after the incidence plug and the reflection plug are assembled with the protective sleeve, so that the manufacturing process is greatly simplified, the manufacturing efficiency is improved, and the production cost is reduced. Meanwhile, the protective sleeve is cylindrical, when the fluid is measured in the fluid, the pressure applied to the surface of the protective sleeve by the fluid acts on the protective sleeve along the radial direction of the protective sleeve, and the same pressure is uniformly distributed along the circumferential direction to form balance between the protective sleeve and the protective sleeve, so that the protective sleeve can be prevented from being deformed and damaged along the radial direction, and the pressure bearing capacity is high. In addition, when using under high temperature environment, protective case can cause the Fabry-Perot chamber to lengthen along axial extension under the effect of expend with heat and contract with cold, meanwhile, incident cock stem and reflection cock stem also can be along axial extension under high temperature, and because protective case's both ends tip and incident cock stem and reflection cock stem sealing connection for incident cock stem and reflection cock stem extend towards the Fabry-Perot chamber, make the Fabry-Perot chamber shorten, thereby compensate protective case's deformation influence under high temperature environment, realized the compensation to the temperature promptly, avoid sensor self expend with heat and contract with cold to influence testing result, guarantee measurement accuracy.
Further, the incident plug and the reflection plug comprise coaxially arranged plug sections and limit sections, and the diameters of the plug sections are matched with the inner diameter of the protective sleeve and are plugged in the protective sleeve; the diameter of the limiting section is larger than the inner diameter of the protective sleeve, and the limiting section is fixed at the end part of the protective sleeve in a fitting and sealing mode.
The limiting section is fixed at the end part of the protective sleeve in a bonding and sealing way, so that the plug-in sections of the incident plug and the reflecting plug are completely plugged into the protective sleeve, and at the moment, the Fabry-Perot cavity length between the incident plug and the reflecting plug is the difference value between the length of the protective sleeve and the total length of the two plug-in sections. Therefore, the initial length of the Fabry-Perot cavity can be ensured by only controlling the plug-in section length of the incident plug and the reflection plug, the manufacturing difficulty is greatly reduced, and the consistency of products is improved.
As another optimization, the reflection plug comprises a plug section and a limit section which are coaxially arranged, wherein the diameter of the plug section is matched with the inner diameter of the protective sleeve, the plug section is plugged in the protective sleeve, and the diameter of the limit section is larger than the inner diameter of the protective sleeve and is fixed at the end part of the protective sleeve in a fitting and sealing way; the outer diameter of the incident plug is matched with the inner diameter of the protective sleeve, so that the incident plug and the protective sleeve form interference fit or transition fit.
In the above-mentioned structure, the protection intraductal has all been plugged into to the stopper section of reflection cock, this moment, the initial length in Fabry-Perot chamber depends on the volume of inserting of incident cock, because form transition or interference fit's relation between incident cock and the protection sleeve, make the incident cock can receive frictional resistance at the in-process of inserting, just so can let the incident cock slowly insert the protection sleeve through controlling the size of inserting the power, detect the signal of incident optic fibre through equipment simultaneously, once the signal that detects satisfies the requirement, indicate that the Fabry-Perot chamber length at this moment satisfies initial chamber length, just remove the force of inserting, accomplish the packing of incident cock. Under the high temperature environment, on the one hand, the friction between incident plug and the protective sleeve can be overcome to the incident plug, and the elongation of the protective sleeve is compensated towards the elongation of Fabry-Perot cavity direction. On the other hand, the incident plug and the protective sleeve can generate thermal deformation in the radial direction, and the protective sleeve is in the outer side, directly contacts with a high-temperature environment, the temperature is relatively high, the deformation is larger, so that the friction force between the incident plug and the protective sleeve can be reduced, and even gaps can be formed, so that the incident plug can be more conveniently stretched inwards relative to the protective sleeve.
Furthermore, a sealing sleeve is sleeved on the incident plug, and the inner diameter of the sealing sleeve is larger than the outer diameter of the incident plug and is hermetically sleeved on the protective sleeve.
In this way, the exposed incident plugs can be protected by the sealing sleeve.
Further, the mounting part is a mounting seat arranged on the protective sleeve, and the bottom surface of the mounting seat is parallel to the axis of the protective sleeve.
Further, the mounting seat is integrally formed on the protective sleeve.
Therefore, after the measured object is deformed, the deformation can be reflected on the elongation of the protective sleeve more accurately, so that the detection accuracy is improved.
Furthermore, the opposite ends of the incident plug and the reflecting plug are respectively provided with a reflecting surface formed by grinding and polishing.
Further, a transmission sheet made of transparent material is further arranged at one end of the incident plug towards the reflection plug, and the thermal expansion coefficient of the transmission sheet is different from that of the incident plug and that of the optical fiber; and a Fabry-Perot cavity is formed between one side of the transmission sheet, which faces the reflection plug, and the reflection surface of the reflection plug.
By arranging the transmission sheet, the flatness of the reflecting surfaces at the two ends of the Fabry-Perot cavity can be ensured, and the problem of cavity length change caused by the fact that the optical fiber is not on the same plane with the grinding surface of the incident plug due to manufacturing reasons is avoided; in addition, when the temperature changes, the thickness of the transmission sheet changes along with the temperature change, the front surface and the rear surface of the transmission sheet form an Fabry-Perot cavity with another cavity length, and the temperature information can be detected simultaneously by demodulating the cavity length information, so that the sensor can detect two physical quantities of strain and temperature simultaneously.
Further, the transmission sheet is a sapphire sheet.
A method for manufacturing the optical fiber Fabry-Perot sensor is characterized in that an incident optical fiber is coaxially buried in an incident plug, and one side of the incident plug opposite to a reflecting plug is polished; and plugging the polished incident plug and the polished reflection plug into the protective sleeve from two ends, and sealing and fixing the polished incident plug and the polished reflection plug after controlling the distance between the incident plug and the polished reflection plug.
In conclusion, the optical fiber Fabry-Perot sensor has the advantages of ingenious structure, simple manufacturing process and the like, and the manufacturing method of the optical fiber Fabry-Perot sensor has the advantages of being beneficial to improving production efficiency, reducing production cost and the like.
Drawings
Fig. 1 is a schematic structural diagram of embodiment 1.
Fig. 2 is another structural schematic diagram of embodiment 1.
Fig. 3 is a schematic structural diagram of embodiment 2.
Fig. 4 is a schematic structural diagram of embodiment 3.
Description of the embodiments
The present invention will be described in further detail with reference to examples.
Example 1: as shown in fig. 1 and 2, an optical fiber fabry-perot sensor comprises a protective sleeve 1 which is integrally cylindrical, wherein two ends of the protective sleeve 1 are provided with mounting parts for being fixed on the surface of an object to be measured, an incident plug 2 and a reflecting plug 3 are respectively plugged, and a fabry-perot cavity is formed between the incident plug 2 and the reflecting plug 3 at intervals; an incident optical fiber coaxially arranged is embedded in the incident plug 2, and one end of the reflecting plug 3 facing the incident plug 2 is a reflecting surface; the two end parts of the protective sleeve 1 are respectively connected with the incident plug 2 and the reflection plug 3 in a sealing way. In order to ensure the pressure-bearing capacity of the protective sleeve, in this embodiment, the protective sleeve 1 is made of a metal capillary.
The incident plug column 2 and the reflection plug column 3 comprise coaxially arranged plug-in sections and limit sections, wherein the diameters of the plug-in sections are matched with the inner diameter of the protective sleeve 1 and are plugged in the protective sleeve 1; the diameter of the limiting section is larger than the inner diameter of the protective sleeve 1, and the limiting section is fixed at the end part of the protective sleeve 1 in a fitting and sealing mode. In this embodiment, the sum of the length of the plug section of the incident plug 2, the length of the plug section of the reflection plug 3 and the original length of the fabry-perot cavity is equal to the length of the protective sleeve 1.
In this embodiment, the mounting portion is a mounting seat 5 disposed on the protective sleeve 1, as shown in fig. 2, the bottom surface of the mounting seat 5 is parallel to the axis of the protective sleeve 1, and the mounting seat 5 is integrally disposed on the protective sleeve 1. In a specific implementation, the two mounting seats 5 may extend along the length direction of the protection sleeve 1 to form an integral structure, as shown in fig. 1.
Because the both ends tip of protective sleeve 1 respectively with incident cock stem 2 and reflection cock stem 3 sealing connection, usually the welding, the welding seam is located the outside of mount pad, during operation, the atress of mount pad department can not influence the welding seam between incident cock stem 2 and reflection cock stem 3 and the protective sleeve 1, avoids the welding seam atress to cause the welding seam to fail the risk of sealing requirement.
In this embodiment, the initial length of the fabry-perot cavity is controlled by the plug-in lengths of the incident plug 2 and the reflective plug 3, and the plug-in lengths of the plug-in lengths are controlled by the joint between the limiting sections and the end portions of the protective sleeves, so that the plug-in lengths of the incident plug 2 and the reflective plug 3 are not strictly matched with the inner holes of the protective sleeves, and for facilitating smooth plug-in of the plug-in lengths, clearance fit is formed between the plug-in lengths of the incident plug 2 and the reflective plug 3 and the protective sleeves. On one hand, the plug section and the inner wall of the protective sleeve can be prevented from being stressed by contact under the conditions of high temperature or accidental bending and the like, so that the flatness of the end face of the Fabry-Perot cavity is affected; on the other hand, friction forces when the plug sections of the entrance plug 2 and the reflection plug 3 are extended relative to the protective sleeve can also be reduced or eliminated.
Meanwhile, in order to better eliminate the influence of thermal expansion and cold contraction on the length of the Fabry-Perot cavity, the materials adopted by the protective sleeve 1, the incident plug 2 and the reflecting plug 3 are the same, so that the thermal expansion elongation of the incident plug 2 and the reflecting plug 3 can compensate the thermal expansion elongation of the protective sleeve 1, the influence factors of high temperature on the elongation of the Fabry-Perot cavity are eliminated, and the detection precision is improved. On the other hand, the effect of sealing and welding is prevented from being influenced by different materials.
The optical fiber Fabry-Perot sensor of the embodiment is manufactured by the following steps.
Firstly, processing a through hole on an incident plug, enabling an incident optical fiber to pass through the through hole, filling nano silver into the hole, and then sintering and solidifying the nano silver in the incident plug by using a muffle furnace according to sintering conditions of the nano silver.
The opposite sides of the incident plug and the reflection plug embedded with the incident optical fiber are polished to form an incident end face and a reflection face. In practice, a reflective film may be coated on the reflective surface of the reflective plug.
When grinding is carried out, the length of the plug section of the incident plug column 2 and the length of the plug section of the reflecting plug column 3 are controlled, and the difference between the length of the plug section and the length of the protective sleeve is ensured to be equal to the initial length of the Fabry-Perot cavity.
The incident plug 2 and the reflection plug 3 are respectively plugged into the protective sleeve from two ends, the limiting section of the reflection plug 3 is abutted on the protective sleeve, and the incident plug is regulated to enable the initial cavity to be grown to meet the requirement.
The reflecting plug 3 is welded on the protective sleeve in a sealing way by laser welding, and the incident plug 2 is welded on the protective sleeve.
After the steel pipe and the sealing sleeve are sealed and welded, the steel pipe is sleeved on the incident plug, and is sealed and welded with the protection sleeve, so that the steel pipe can be used for protecting the incident plug while sealing is formed.
When the device is used, the two ends of the protective sleeve are respectively fixed on the surface of an object to be measured, once the surface of the object to be measured deforms, the length of the protective sleeve can be changed, and the length change of the protective sleeve is represented by the change of the length of the Fabry-Perot cavity, so that the strain can be measured.
In this embodiment, the limiting sections of the incident plug 2 and the reflective plug 3 are abutted against the protective sleeve, so that the initial length of the fabry-perot cavity can be directly ensured by using the plug section length of the incident plug 2 and the plug section length of the reflective plug 3, thereby greatly saving the time for adjusting to ensure the initial length. In addition, in the process of assembling the shell (the protective sleeve), the Fabry-Perot cavity structure is directly formed, the Fabry-Perot cavity sensor body with the glass structure is not required to be manufactured first, and then the Fabry-Perot cavity sensor body is packaged, so that the manufacturing process is greatly simplified, the production time is saved, and the production cost is reduced. Moreover, the optical fiber Fabry-Perot sensor packaged by the embodiment can directly reflect the deformation of the measured object to the deformation of the protective sleeve, and the measurement is more accurate.
In addition, because the protective sleeve is cylindric, when measuring in the fluid, the pressure of fluid application on the protective sleeve surface is on the protective sleeve along the radial of protective sleeve, because the same pressure is along circumference equipartition, forms the balance each other to can avoid protective sleeve to take place deformation in radial and damage, bearing capacity is strong.
Example 2: in embodiment 1, the initial length of the fabry-perot cavity is achieved by controlling the plug-in section length of the incident plug 2 and the plug-in section length of the reflective plug 3, specifically, in order to better control the fabry-perot cavity length, the incident plug 2 is usually first ground and then installed in the protective sleeve, and then the reflective plug 3 is ground until the plug-in section length of the reflective plug 3 meets the requirement and then installed in the protective sleeve.
Thus, if the polishing amount per time is too small, the polishing needs to be continued for a plurality of times to meet the requirement. If the grinding amount is too large, the initial length of the Fabry-Perot cavity cannot be met, so that flaws are caused.
For this reason, this embodiment is further modified on the basis of embodiment 1 as follows:
as shown in fig. 3, the protective sleeve 1 is further provided with a coaxially arranged stop collar 4, the outer diameter of the stop collar 4 is matched with the inner diameter of the protective sleeve 1, and the stop collar 4 is slidably arranged in the protective sleeve 1, and the inner diameter of the stop collar 4 is larger than the diameter of the incident optical fiber; the length of the limiting sleeve 4 is consistent with the initial length of the Fabry-Perot cavity, and the limiting sleeve is abutted between the incidence plug 2 and the reflection plug 3.
Therefore, the length of the incidence plug column 2 and the reflection plug column 3 is controlled by the butt joint of the limit sleeve 4, and the difference between the length of the protective sleeve and the plug section length of the incidence plug column 2 and the plug section length of the reflection plug column 3 is only required to be ensured to be larger than the initial length of the Fabry-Perot cavity during grinding production, so that the production difficulty is greatly reduced, and the consistency of products is ensured.
Example 3: the present embodiment is further modified on the basis of embodiment 1 as follows:
as shown in fig. 4, the reflection plug 3 includes a plug section and a limit section coaxially disposed, wherein the diameter of the plug section is matched with the inner diameter of the protection sleeve 1, and is plugged into the protection sleeve 1, and the diameter of the limit section is larger than the inner diameter of the protection sleeve 1, and is fixed at the end of the protection sleeve 1 in a fitting and sealing manner; the outer diameter of the incident plug 2 is matched with the inner diameter of the protective sleeve 1, so that the incident plug and the protective sleeve form interference fit or transition fit.
The reflective plugs 3 in this embodiment are identical to all the arrangements of the reflective plugs 3 in embodiment 1, and the plug sections of the reflective plugs are all plugged into the protective sleeve, at which point the initial length of the fabry-perot cavity depends on the amount of plugging of the incident plugs. Because the interference or transition fit relation is between incident cock stem and the protective sleeve for incident cock stem is gone into the protective sleeve in-process, can receive the resistance of protective sleeve inner wall, and incident cock stem need receive external knocking and just can slowly be plugged into the protective sleeve in, only need control the knocking force, just can control incident cock stem and go into the length of protective sleeve, when beating, link up optic fibre and equipment, whether plug dress is put in place through observation equipment display result, confirm incident cock stem. Meanwhile, by utilizing interference or transition fit of the two, once the incident plug is knocked in place, the two are fixedly assembled. Under the high temperature environment, on the one hand, the friction between incident plug and the protective sleeve can be overcome to the incident plug, and the elongation of the protective sleeve is compensated towards the elongation of Fabry-Perot cavity direction. On the other hand, the incident plug and the protective sleeve can generate thermal deformation in the radial direction, and the protective sleeve is in the outer side, directly contacts with a high-temperature environment, the temperature is relatively high, the deformation is larger, so that the friction force between the incident plug and the protective sleeve can be reduced, and even gaps can be formed, so that the incident plug can be more conveniently stretched inwards relative to the protective sleeve. In order to allow the plug section of the inlet plug to be better extended relative to the protective sleeve, the mating relationship between the inlet plug 2 and the protective sleeve 1 is preferably a transition fit.
The plug section of the incident plug 2 can be set to be two sections, including a primary plug section completely plugged into the protective sleeve 1, and a fine-tuning plug section forming interference fit or transition fit with the protective sleeve 1, wherein the diameter of the primary plug section is smaller than the inner diameter of the protective sleeve 1, and the sum of the length of the primary plug section, the length of the plug section of the reflection plug 3 and the initial length of the Fabry-Perot cavity is smaller than the length of the protective sleeve 1. Therefore, the primary plug loading section can be firstly plugged into the protective sleeve, and then the primary cavity length can be controlled by further adjusting the fine plug loading section through interference fit or transition fit. Because the diameter of the primary plug section is smaller than the inner diameter of the protective sleeve 1, the primary plug section is easier to extend inwards relative to the protective sleeve 1.
For further protection, in this embodiment, the incident plug 2 is sleeved with a sealing sleeve 6, and the inner diameter of the sealing sleeve 6 is larger than the outer diameter of the incident plug 2 and is hermetically sleeved on the protection sleeve 1. In addition, the incident plug, the reflection plug, the protective sleeve and the sealing sleeve are made of the same material, so that the consistent thermal expansion coefficient is ensured.
Example 4: the embodiment is modified on the basis of embodiment 1, one end of the incident plug 2 facing the reflection plug 3 is further provided with a transmission sheet made of transparent material, and the thermal expansion coefficient of the transmission sheet is different from the thermal expansion coefficients of the incident plug 2 and the optical fiber; and a Fabry-Perot cavity is formed between one side of the transmission sheet, which faces the reflection plug 3, and the reflection surface of the reflection plug 3. The transmissive sheet in this embodiment is a sapphire sheet.
By arranging the transmission sheet, the flatness of the reflecting surfaces at the two ends of the Fabry-Perot cavity can be ensured, and the problem of cavity length change caused by the fact that the optical fiber is not on the same plane with the grinding surface of the incident plug due to manufacturing reasons is avoided; in addition, when the temperature changes, the thickness of the transmission sheet changes along with the temperature change, the front surface and the rear surface of the transmission sheet form an Fabry-Perot cavity with another cavity length, and the temperature information can be detected simultaneously by demodulating the cavity length information, so that the sensor can detect two physical quantities of strain and temperature simultaneously.
The foregoing description of the preferred embodiments of the invention is not intended to be limiting, but rather is intended to cover all modifications, equivalents, and alternatives falling within the spirit and principles of the invention.
Claims (10)
1. The optical fiber Fabry-Perot sensor is characterized by comprising a protective sleeve (1) which is integrally cylindrical, wherein two ends of the protective sleeve (1) are provided with mounting parts which are used for being fixed on the surface of an object to be measured, an incident plug (2) and a reflecting plug (3) are respectively plugged, and Fabry-Perot cavities are formed between the incident plug (2) and the reflecting plug (3) at intervals; an incident optical fiber which is coaxially arranged is embedded in the incident plug (2), and one end of the reflecting plug (3) facing the incident plug (2) is a reflecting surface; the two end parts of the protective sleeve (1) are respectively connected with the incident plug (2) and the reflecting plug (3) in a sealing way.
2. The optical fiber Fabry-Perot sensor according to claim 1, wherein the incidence plug (2) and the reflection plug (3) comprise a plug-in section and a limit section which are coaxially arranged, and the diameter of the plug-in section is matched with the inner diameter of the protective sleeve (1) and is plugged in the protective sleeve (1); the diameter of the limiting section is larger than the inner diameter of the protective sleeve (1), and the limiting section is fixed at the end part of the protective sleeve (1) in a fitting and sealing manner.
3. The optical fiber Fabry-Perot sensor according to claim 1, wherein the reflection plug (3) comprises a plug section and a limit section which are coaxially arranged, the diameter of the plug section is matched with the inner diameter of the protective sleeve (1) and plugged into the protective sleeve (1), and the diameter of the limit section is larger than the inner diameter of the protective sleeve (1) and is fixedly attached to the end part of the protective sleeve (1) in a fitting and sealing way; the outer diameter of the incident plug (2) is matched with the inner diameter of the protective sleeve (1), so that the incident plug and the protective sleeve form interference fit or transition fit relation.
4. A fiber optic fabry-perot sensor as claimed in claim 3, wherein the incident plug (2) is provided with a sealing sleeve (6), the sealing sleeve (6) having an inner diameter larger than the outer diameter of the incident plug (2) and being sealingly arranged over the protective sleeve (1).
5. The optical fiber fabry-perot sensor according to claim 1, characterized in that the mounting part is a mounting seat (5) arranged on the protective sleeve (1), the bottom surface of the mounting seat (5) being parallel to the axis of the protective sleeve (1).
6. A fiber optic fabry-perot sensor according to claim 5, characterized in that the mounting socket (5) is integrally provided on the protective sleeve (1).
7. A fiber optic fabry-perot sensor according to claim 1, wherein the opposite ends of the entrance plug (2) and the reflection plug (3) each have a polished reflective surface.
8. An optical fiber fabry-perot sensor according to any one of claims 1 to 7, characterized in that the end of the entrance plug (2) facing the reflection plug (3) is further provided with a transmissive sheet made of a transparent material, the coefficient of thermal expansion of the transmissive sheet being different from the coefficients of thermal expansion of the entrance plug (2) and the optical fiber; and an Fabry-Perot cavity is formed between one side of the transmission sheet, which faces the reflection plug (3), and the reflection surface of the reflection plug (3).
9. A fiber optic fabry perot sensor according to claim 8, wherein the transmissive sheet is a sapphire sheet.
10. A method of making an optical fiber fabry-perot sensor according to any one of claims 1 to 9, wherein an incident optical fiber is coaxially embedded in an incident plug and polished on the opposite side of the incident plug from a reflective plug; and plugging the polished incident plug and the polished reflection plug into the protective sleeve from two ends, and sealing and fixing the polished incident plug and the polished reflection plug after controlling the distance between the incident plug and the polished reflection plug.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211660571.9A CN115930814A (en) | 2022-12-23 | 2022-12-23 | Optical fiber Fabry-Perot sensor and manufacturing method thereof |
| CN2022116605719 | 2022-12-23 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN116242405A true CN116242405A (en) | 2023-06-09 |
Family
ID=85837857
Family Applications (2)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211660571.9A Pending CN115930814A (en) | 2022-12-23 | 2022-12-23 | Optical fiber Fabry-Perot sensor and manufacturing method thereof |
| CN202310367870.1A Pending CN116242405A (en) | 2022-12-23 | 2023-04-07 | Optical fiber Fabry-Perot sensor and manufacturing method thereof |
Family Applications Before (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211660571.9A Pending CN115930814A (en) | 2022-12-23 | 2022-12-23 | Optical fiber Fabry-Perot sensor and manufacturing method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (2) | CN115930814A (en) |
-
2022
- 2022-12-23 CN CN202211660571.9A patent/CN115930814A/en active Pending
-
2023
- 2023-04-07 CN CN202310367870.1A patent/CN116242405A/en active Pending
Also Published As
| Publication number | Publication date |
|---|---|
| CN115930814A (en) | 2023-04-07 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CA2676246C (en) | Transducer for measuring environmental parameters | |
| JP5021457B2 (en) | Optical sensor | |
| US7017417B2 (en) | Pressure sensor assembly suitable for use in harsh environments | |
| US7173713B2 (en) | Optical fiber sensors for harsh environments | |
| US7134346B2 (en) | Differential pressure transducer with Fabry-Perot fiber optic displacement sensor | |
| CN102607761B (en) | Temperature self-correcting and manufacturing methods for Dual-Fabry-Perot optical fiber pressure sensor | |
| CN104880267A (en) | Fiber micro-nano Fabry-Perot interference type pressure sensor and manufacturing method thereof | |
| CN102587893B (en) | Optic fiber temperature pressure sensor and probe thereof | |
| WO2003050492A1 (en) | Measuring shear stress at an interface with two walls and two crossed sensor elements | |
| JPH07151624A (en) | Optical-fiber high-temperature pressure sensor | |
| CN112525237B (en) | EFPI-FBG composite pressure and temperature sensor based on epoxy resin packaging and measuring method | |
| CN203163913U (en) | Diaphragm type fiber bragg grating pressure sensor with temperature compensation | |
| US9810594B2 (en) | Thermally stable high temperature pressure and acceleration optical interferometric sensors | |
| CN107300437B (en) | Optical fiber pressure sensor based on micro-ellipsoidal air cavity and manufacturing method thereof | |
| CN105051512A (en) | Optical sensor for contactless pressure measurements | |
| CN111595256A (en) | High-temperature-resistant optical fiber strain sensor | |
| CN105953958A (en) | All-silica fiber Fabry-Perot pressure sensor | |
| CN213902404U (en) | Double-sleeve packaged optical fiber high-temperature pressure sensor | |
| CN212721825U (en) | Optical fiber temperature sensor based on temperature sensitive material modulation FP cavity | |
| CN116242405A (en) | Optical fiber Fabry-Perot sensor and manufacturing method thereof | |
| US8170382B2 (en) | Fiber-optic temperature sensor assembly | |
| CN211234773U (en) | FP chamber temperature sensor based on optic fibre wire jumper | |
| CN113188691A (en) | Optical fiber Fabry-Perot sealed cavity pressure sensor and preparation method thereof | |
| US10753775B1 (en) | Optical fiber flow sensor | |
| CN114485986B (en) | Optical fiber FP temperature sensor sensitized by external structure and preparation method thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |