Integrated high-temperature optical fiber sensor coupling packaging device and method based on laser welding

Abstract

The present invention relates to the field of high-temperature sensor coupling and packaging, and specifically, to an integrated high-temperature optical fiber sensor coupling and packaging device and method based on laser welding. The device comprises a laser welding module, a motion control module, and a signal detection module. The laser welding module is used to provide a welding laser to the motion control module, thereby welding and fixing the tail end of the optical fiber pigtail to the sensitive unit. The motion control module includes a base three-dimensional translation stage, a five-dimensional optical fiber translation stage, an optical fiber clamp, a sensitive unit clamp, a rotation stage, and a three-dimensional sensitive unit translation stage, which are used to align and adjust the welding position. The signal detection module is used to monitor the spectral signal in the sensor in real time. The present invention can achieve integrated coupling and packaging of high-temperature optical fiber sensors using homogeneous materials.

Description

Technical Field

[0001] The present invention relates to the field of high-temperature sensor coupling packaging, and in particular to an integrated high-temperature optical fiber sensor coupling packaging device and method based on laser welding. Background Art

[0002] With the rapid development of modern technology, the demand for high-temperature sensors is increasing in fields such as aerospace, energy, and chemical engineering. In extreme environments like high temperatures, the accurate measurement of parameters such as noise, vibration, pressure, strain, and refractive index not only affects equipment performance and safety, but also directly impacts production efficiency and product quality.

[0003] Traditional electrical sensors in China are unable to operate stably and long-term under high-temperature conditions due to defects such as high-temperature structural failure, significantly limiting their applicability and reliability in high-temperature environments. In contrast, optical sensors have become a research hotspot in the sensor field due to their low cost, small size, immunity to electromagnetic interference, and high-temperature resistance. However, most current high-temperature fiber optic sensors use high-temperature adhesive for coupling, which has certain limitations in high-temperature environments. This is mainly reflected in the mismatch between the high-temperature adhesive and the material of the device's sensitive elements, which can lead to thermal stress mismatch, thus affecting signal detection accuracy. Furthermore, the long-term mechanical stability of high-temperature adhesive is poor, and performance degradation can occur with prolonged high-temperature measurements.

[0004] Therefore, it is necessary to invent an integrated high-temperature optical fiber sensor coupling packaging method to obtain an integrated sensor device based on homogeneous materials to meet the development needs of high-temperature in-situ parameter testing in application fields such as petroleum exploration, aerospace, and non-destructive testing. Summary of the Invention

[0005] In order to overcome the technical bottleneck of performance degradation of sensors in high temperature environments in the existing technology, the present invention proposes an integrated high-temperature optical fiber sensor coupling packaging device and method based on a carbon dioxide laser welding system, which eliminates the influence of thermal stress mismatch on signal detection accuracy in high temperature environments and improves the long-term stability of the sensor in high temperature environments.

[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is: an integrated high-temperature optical fiber sensor coupling packaging device based on laser welding, comprising: a laser welding module, a motion control module and a signal detection module;

[0007] The laser welding module is used to provide welding laser to the motion control module so that the tail end of the optical fiber pigtail is welded and fixed to the sensitive unit;

[0008] The motion control module includes a base three-dimensional displacement stage, a fiber five-dimensional displacement stage, a fiber clamp, a sensitive unit clamp, a rotating stage, and a sensitive unit three-dimensional displacement stage; the fiber five-dimensional displacement stage and the sensitive unit three-dimensional displacement stage are fixed on the base three-dimensional displacement stage; the fiber clamp is fixed on the fiber five-dimensional displacement stage; the sensitive unit clamp is fixed on the rotating stage, and the rotating stage is fixed on the sensitive unit three-dimensional displacement stage; the fiber clamp is used to clamp the fiber pigtail, and the sensitive unit clamp is used to clamp the sensitive unit;

[0009] The optical fiber five-dimensional displacement stage is used to cooperate with the three-dimensional displacement stage of the sensitive unit to achieve alignment between the sensitive unit and the end of the optical fiber pigtail; the three-dimensional displacement stage of the base is used to achieve alignment between the sensor welding position and the focused spot of the welding laser; the rotating stage is used to rotate the clamping part of the sensitive unit in a plane perpendicular to the direction of the optical fiber pigtail to achieve switching of the welding position;

[0010] The signal detection module includes a detection light source, a circulator and a spectrometer. The detection light source is connected to the optical fiber pigtail through the circulator. The detection laser output by the detection light source is transmitted to the sensitive unit through the circulator and the optical fiber, and is reflected back and forth between the sensitive unit and the end face of the optical fiber pigtail to form a double-beam interference; the interference signal is output from the optical fiber pigtail and transmitted to the spectrometer through the circulator, and the spectral signal of the sensor is monitored in real time by the spectrometer.

[0011] The laser welding module includes: a carbon dioxide laser, a controller, a first light guide unit, a first variable magnification beam expander and a first focusing lens. The controller is used to adjust the power and time of the laser output by the carbon dioxide laser; the laser output by the carbon dioxide laser is incident and focused to the welding position after passing through the first light guide unit, the first variable magnification beam expander and the first focusing lens; the variable magnification beam expander is used to adjust the laser beam spot size, and the first focusing lens is used to focus the laser beam.

[0012] The laser welding module also includes a beam splitter prism, a second light guide unit, a second variable magnification beam expander and a second focusing lens. The laser output by the carbon dioxide laser is incident on the beam splitter prism after passing through the first light guide unit, and is divided into two beams by the beam splitter prism. One beam is incident on and focused on the welding position after passing through the first variable magnification beam expander and the first focusing lens, and the other beam is incident on and focused on the other welding position after passing through the second light guide unit, the second variable magnification beam expander and the second focusing lens.

[0013] The first light guiding unit and the second light guiding unit each include two reflecting mirrors.

[0014] The integrated high-temperature optical fiber sensor coupling and packaging device based on laser welding further includes an electron microscope and a display screen. The electron microscope is connected to the display screen and is used to observe the welding position and welding status of the sensor in real time.

[0015] The sensitive unit clamping member is provided with a sensitive unit clamping area and a capillary clamping area; the capillary clamping area is used to fix the capillary, and the optical fiber five-dimensional displacement stage is also used to move the tail end of the optical fiber pigtail to achieve alignment between the optical fiber pigtail and the capillary; the sensitive unit clamping area is used to fix the sensitive unit.

[0016] The sensitive unit clamping part includes a U-shaped base, in which a first slide and a second slide are arranged, a first slider is arranged on the first slide, and a second slider is arranged on the second slide, and a first lead screw and a second lead screw are arranged on one side wall of the U-shaped base, the end of the first lead screw contacts the first slider to push the first slider to slide along the first slide and thus fix the sensitive unit; the end of the second lead screw contacts the second slider to push the second slider to slide along the second slide and thus fix the capillary.

[0017] The detection light source is an ASE light source with a wavelength of 1550 nm.

[0018] In addition, the present invention also provides an integrated high-temperature optical fiber sensor coupling packaging method based on laser welding, which is implemented based on the coupling packaging device described above and includes the following steps:

[0019] Step 1: Clean the sensitive unit and capillary tube respectively and fix them to the sensitive unit clamping area and the capillary tube clamping area, and cut the end face of the optical fiber pigtail flat and fix it to the optical fiber clamping piece;

[0020] Step 2: Control the movement of the optical fiber five-dimensional translation stage to insert the optical fiber pigtail into the capillary, and keep the end face of the optical fiber flush with the end face of the capillary;

[0021] Step 3: Control the movement of the three-dimensional translation stage of the base to achieve alignment between the welding position between the optical fiber pigtail and the capillary and the focused spot of the welding laser; control the output power and output time of the laser welding module to achieve welding between the capillary and the optical fiber pigtail;

[0022] Step 4: After the capillary and the fiber pigtail are fused, remove the capillary from the capillary clamping area, control the movement of the optical fiber five-dimensional translation stage to insert the capillary into the sensitive unit; control the movement of the base three-dimensional translation stage to achieve alignment between the fusion position between the fiber pigtail and the capillary and the focused spot of the fusion laser;

[0023] Step 5: The signal monitoring module monitors the sensor's interference signal in real time, and adjusts the optical fiber five-dimensional translation stage and the sensitive unit three-dimensional translation stage to change the relative angle and position between the capillary with the pigtail and the sensitive unit until the interference signal detected by the signal monitoring module is the strongest. The laser welding module then controls the output power and output time of the laser to achieve preliminary welding between the capillary and the sensitive unit.

[0024] Step 6: After the initial fusion between the capillary and the sensitive unit is completed, loosen the fiber clamp, control the rotation of the rotary table to drive the capillary and the sensitive unit to rotate, and perform fusion at the next fusion position between the capillary and the sensitive unit.

[0025] The step 3 specifically includes the following steps:

[0026] Step 3.1: Control the movement of the three-dimensional translation stage of the base to align the first welding position between the optical fiber pigtail and the capillary with the focused spot of the welding laser; control the output power and output time of the laser welding module to achieve welding between the capillary and the optical fiber pigtail;

[0027] Step 3.2: Control the base three-dimensional translation stage to move along the axial direction of the optical fiber pigtail to align the next axial welding position between the optical fiber pigtail and the capillary with the focused spot of the welding laser. Then, control the output power and output time of the laser welding module to achieve welding between the capillary and the optical fiber pigtail. Repeat the above steps to achieve multi-position welding between the capillary and the optical fiber pigtail.

[0028] Said step 6 specifically includes the following steps: after the preliminary fusion between the capillary and the sensitive unit is completed, the optical fiber clamp is loosened, the rotation table is controlled to rotate to drive the capillary and the sensitive unit to rotate, and the three-dimensional translation stage of the base is controlled to move to achieve alignment between the next fusion position of the same circle between the optical fiber pigtail and the capillary and the focused spot of the fusion laser, and the next fusion position between the capillary and the sensitive unit is fused.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] The integrated high-temperature fiber optic sensor coupling and packaging device proposed in this invention integrates a laser welding module, a motion control module, a signal monitoring module, and a spatial five-axis system. This improves the accuracy of device welding coupling. The cleverly designed fixture is compatible with different structures to be welded. Furthermore, the sensor device signal can be monitored in real time during the laser welding process for optimization and adjustment. This invention improves device manufacturing efficiency while ensuring the excellent overall performance of the integrated sensor.

[0031] 2. The present invention adopts laser welding to replace the traditional high-temperature glue coupling packaging method for the sensitive unit, capillary and optical fiber pigtail of homogeneous glass materials, which can realize the integrated coupling packaging of homogeneous materials, eliminate the problem of thermal stress mismatch between different materials in high-temperature environments, and improve the measurement accuracy and long-term stability of the sensor's in-situ detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 A schematic structural diagram of a high-temperature sensor coupling and packaging device provided in Embodiment 1 of the present invention;

[0033] Figure 2 Schematic diagram of the structure of the motion control system used in an embodiment of the present invention;

[0034] Figure 3 This is a schematic structural diagram of a sensitive unit clamping member according to an embodiment of the present invention;

[0035] Figure 4 A schematic structural diagram of a high-temperature sensor coupling and packaging device according to a second embodiment of the present invention;

[0036] Figure 5 Schematic diagram of each laser welding point in an embodiment of the present invention;

[0037] Figure 6 Schematic diagram of each laser welding point in an embodiment of the present invention.

[0038] In the figure, 1-CO2 laser, 2-controller, 3-first 45° reflector, 4-second 45° reflector, 5-beam splitter, 6-first variable magnification beam expander, 7-first focusing lens, 8-third 45° reflector, 9-fourth 45° reflector, 10-second variable magnification beam expander, 11-second focusing lens, 12-detection light source, 13-circulator, 14-spectrometer, 15-base three-dimensional translation stage, 16-fiber five-dimensional translation stage, 17-fiber clamp, 18-sensitive unit clamp Holder, 19-rotating stage, 20-sensitive unit three-dimensional translation stage, 21-sensitive unit, 22-capillary, 23-optical fiber pigtail, 24-electron microscope, 25-display screen, 18-1-U-shaped base, 18-2-first slide, 18-3-second slide, 18-4 first slider, 18-5-second slider, 18-6-first lead screw, 18-7-second lead screw, 26-1 first welding position, 26-2 second welding position, 26-3 third welding position, 26-4 fourth welding position. DETAILED DESCRIPTION

[0039] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are part of the embodiments of the present invention, not all the embodiments; based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0040] Example 1

[0041] like Figure 1 As shown, embodiment 1 of the present invention provides an integrated high-temperature optical fiber sensor coupling packaging device based on laser welding, including: a laser welding module, a motion control module and a signal detection module; the laser welding module is used to provide welding laser to the motion control module, so that the tail end of the optical fiber pigtail 23 is welded and fixed to the sensitive unit 21.

[0042] Specifically, if Figures 1 and 2 As shown, the motion control module includes a base three-dimensional translation stage 15, a five-dimensional optical fiber translation stage 16, a fiber clamp 17, a sensitive unit clamp 18, a rotating platform 19, and a three-dimensional sensitive unit translation stage 20. The five-dimensional optical fiber translation stage 16 and the three-dimensional sensitive unit translation stage 20 are fixed to the base three-dimensional translation stage 15. The fiber clamp 17 is fixed to the five-dimensional optical fiber translation stage 16. The sensitive unit clamp 18 is fixed to the rotating platform 19, and the rotating platform 19 is fixed to the three-dimensional sensitive unit translation stage 20. The fiber clamp 17 is used to clamp the optical fiber pigtail 23, and the sensitive unit clamp 18 is used to clamp the sensitive unit 21. In addition, the motion control module also includes a control module for controlling the movements of the base three-dimensional translation stage 15, the five-dimensional optical fiber translation stage 16, the fiber clamp 17, the sensitive unit clamp 18, the rotating platform 19, and the three-dimensional sensitive unit translation stage 20.

[0043] In this embodiment, the optical fiber five-dimensional displacement stage 16 is used to cooperate with the sensitive unit three-dimensional displacement stage 20 to achieve alignment between the sensitive unit 21 and the end of the optical fiber pigtail 23; the base three-dimensional displacement stage 15 is used to achieve alignment between the sensor welding position and the focused spot of the welding laser; the rotating stage 19 is used to rotate the sensitive unit clamp 18 in a plane perpendicular to the direction of the optical fiber pigtail 23 to achieve switching of the welding position.

[0044] Specifically, if Figures 1 and 2As shown, the signal detection module includes a detection light source 12, a circulator 13 and a spectrometer 14. The detection light source 12 is connected to the optical fiber pigtail 23 through the circulator 13. The detection laser output by the detection light source 12 is transmitted to the sensitive unit 21 through the circulator 13 and the optical fiber pigtail 23, and is reflected back and forth between the sensitive unit 21 and the end face of the optical fiber pigtail 23 to form a double-beam interference; the interference signal is output by the optical fiber pigtail 23 and transmitted to the spectrometer 14 through the circulator 13, and the spectral signal of the sensor is monitored in real time by the spectrometer 14.

[0045] Specifically, if Figure 1 As shown, in this embodiment, the laser welding module includes: a carbon dioxide laser 1, a controller 2, a first light guide unit, a first variable magnification beam expander 6 and a first focusing lens 7. The controller 2 is used to adjust the power and time of the laser output by the carbon dioxide laser 1; the laser output by the carbon dioxide laser 1 is incident and focused to the welding position after passing through the first light guide unit, the first variable magnification beam expander 6 and the first focusing lens 7; the variable magnification beam expander 6 is used to adjust the laser beam spot size, and the first focusing lens 7 is used to focus the laser beam.

[0046] Specifically, in this embodiment, the first light guiding unit includes a first 45° reflecting mirror 3 and a second 45° reflecting mirror 4 , and the two second 45° reflecting mirrors can realize the adjustment of the light path.

[0047] Furthermore, the integrated high-temperature optical fiber sensor coupling and packaging device based on laser welding of this embodiment further includes an electron microscope 24 and a display screen 25. The electron microscope 24 is connected to the display screen for real-time observation of the welding position and welding status of the sensor.

[0048] Furthermore, the integrated high-temperature optical fiber sensor coupling and packaging device based on laser welding in this embodiment also includes a housing, within which the electron microscope 24, laser welding module, and motion control module are all disposed. The housing protects the device from external interference, and the electron microscope 24 enables real-time monitoring of the alignment of various sensor structures.

[0049] In this embodiment, the direction of the optical fiber pigtail 23 is defined as the Y-axis, and the plane of the optical fiber clamp 17 is defined as the XY plane. The base three-dimensional translation stage 15 can translate in the X, Y, and Z directions. The optical fiber five-dimensional translation stage 16 can not only move in the X, Y, and Z directions, but also rotate along the X and Z axes to adjust the pitch angle. The three-dimensional translation stage 20 of the sensing unit can be adjusted in the X, Y, and Z directions. These three translation stages form a spatial five-axis system, ensuring that the laser beam accurately reaches the location to be welded, improving the accuracy and efficiency of the welding process. Furthermore, the welding status of the sensor can be observed in real time via an electron microscope 24 connected to a display screen 25.

[0050] Furthermore, in this embodiment, the sensor to be packaged includes not only the optical fiber pigtail 23 and the sensitive unit 21, but also a capillary 22. The end of the optical fiber pigtail 23 is fixed in the capillary 22 by fusion, and the capillary 22 is fixed in the center of the sensitive unit 21 by fusion. Figure 3 As shown, the sensitive unit clamping part 18 is provided with a sensitive unit clamping area and a capillary clamping area; the capillary clamping area is used to fix the capillary 22, and the optical fiber five-dimensional displacement stage 16 is also used to move the tail end of the optical fiber pigtail 23 to achieve alignment between the optical fiber pigtail 23 and the capillary 22; the sensitive unit clamping area is used to fix the sensitive unit 21.

[0051] Furthermore, if Figure 4 As shown, in this embodiment, the sensitive unit clamping member 18 includes a U-shaped base 18-1, and a first slide 18-2 and a second slide 18-3 are provided in the U-shaped base 18-1. A first slider 18-4 is provided on the first slide 18-2, and a second slider 18-5 is provided on the second slide 18-3. A first lead screw 18-6 and a second lead screw 18-7 are provided on one side wall of the U-shaped base 18-1. The end of the first lead screw 18-6 contacts the first slider 18-4 to push the first slider 18-4 to slide along the first slide 18-2 and thereby fix the sensitive unit 21; the end of the second lead screw 18-7 contacts the second slider 18-5 to push the second slider 18-5 to slide along the second slide 18-3 and thereby fix the capillary 22.

[0052] Specifically, in this embodiment, the end of the first lead screw 18-6 contacts the first slider 18-4, and is used to push the first slider 18-4 to slide along the first slide 18-2, thereby fixing the sensitive unit 21 between the first slider 18-4 and the other side wall of the U-shaped base 18-1; the second slider 18-5 is arranged between one side wall of the U-shaped base 18-1 and the first slider 18-4, and the end of the second lead screw 18-7 contacts the second slider 18-5, and is used to push the second slider 18-5 to slide along the second slide 18-3, thereby fixing the capillary 22 between the first slider 18-4 and the second slider 18-5.

[0053] Specifically, in this embodiment, the detection light source 12 is an ASE light source with a wavelength of 1550 nm. The wavelength of the CO2 laser 1 is 10.6 μm. The first variable-magnification beam expander 6 and the first focusing lens 7 can adjust the beam spot to approximately 1 mm, effectively allowing the laser beam to operate on the pigtailed capillary 22. The capillary 22 is made of glass. After absorbing the laser energy, the glass converts it into heat energy, causing the material to melt, thus achieving the laser welding effect.

[0054] Example 2

[0055] like Figure 4 As shown, the second embodiment of the present invention provides an integrated high-temperature optical fiber sensor coupling packaging device, which is the same as the first embodiment in that it includes: a laser welding module, a motion control module and a signal detection module; wherein the laser welding module includes a carbon dioxide laser 1, a controller 2, a first light guide unit, a first variable magnification beam expander 6 and a first focusing lens 7.

[0056] Different from the first embodiment, in this embodiment, the laser welding module further includes a beam splitter prism 5, a second light guide unit, a second variable magnification beam expander 10 and a second focusing lens 11. The laser output by the carbon dioxide laser 1 is incident on the beam splitter prism 5 after passing through the first light guide unit, and is divided into two beams by the beam splitter prism 5. The first beam is incident on and focused on the welding position after passing through the first variable magnification beam expander 6 and the first focusing lens 7. After passing through the second light guide unit, the propagation direction of the second beam is perpendicular to that of the first beam, and then it is incident on and focused on another welding position after passing through the second variable magnification beam expander 10 and the second focusing lens 11.

[0057] In this embodiment, the beam splitter 5 splits the welding laser into two beams, which can achieve simultaneous welding of different positions of the sensor, further improving the coupling packaging efficiency of the sensor device. The beam splitter prism 5 has a splitting ratio of 1:1.

[0058] Specifically, in this embodiment, the second light guiding unit includes a third 45° reflecting mirror 8 and a fourth 45° reflecting mirror 9. The two second 45° reflecting mirrors can adjust the optical path of the second light beam.

[0059] Example 3

[0060] A third embodiment of the present invention provides an integrated high-temperature optical fiber sensor coupling and packaging method based on laser welding, which is implemented based on the coupling and packaging device described in the first or second embodiment and includes the following steps:

[0061] Step 1: Clean the sensitive unit 21 and the capillary 22 respectively and fix them to the sensitive unit clamping area and the capillary clamping area, and cut the end face of the optical fiber pigtail 23 flat and fix it to the optical fiber clamping piece 17.

[0062] Step 2: Control the optical fiber five-dimensional translation stage 16 to move, and then insert the optical fiber pigtail 23 into the capillary 22, and keep the optical fiber end face flush with the capillary end face.

[0063] Step 3: Control the movement of the base three-dimensional translation stage 15 to achieve alignment between the welding position between the optical fiber pigtail 23 and the capillary 22 and the focused spot of the welding laser; control the output power and output time of the laser welding module to achieve welding between the capillary 22 and the optical fiber pigtail 23.

[0064] The step 3 specifically includes the following steps:

[0065] Step 3.1: Control the movement of the base three-dimensional translation stage 15 to achieve alignment between the first welding position between the optical fiber pigtail 23 and the capillary 22 and the focused spot of the welding laser; control the output power and output time of the laser welding module to achieve welding between the capillary 22 and the optical fiber pigtail 23;

[0066] Step 3.2: Control the base three-dimensional translation stage 15 to move axially along the optical fiber pigtail 23 to achieve alignment between the next axial welding position between the optical fiber pigtail 23 and the capillary 22 and the focused spot of the welding laser, and then control the output power and output time of the laser welding module to achieve welding between the capillary 22 and the optical fiber pigtail 23, and then repeat the above steps to achieve multi-position welding between the capillary 22 and the optical fiber pigtail 23.

[0067] like Figure 5 As shown, a first fusion splice position 26-1 and a second fusion splice position 26-2 are provided along the axial direction between the capillary tube 22 and the optical fiber pigtail 23. Through multiple fusion splice positions, a stable connection between the capillary tube 22 and the optical fiber pigtail 23 can be ensured.

[0068] Step 4: After the capillary 22 and the optical fiber pigtail 23 are fused, the capillary 22 is removed from the capillary clamping area 18, and the optical fiber five-dimensional translation stage 16 is controlled to move to insert the capillary 22 into the sensitive unit 21; the base three-dimensional translation stage 15 is controlled to move to achieve alignment between the fusion position between the optical fiber pigtail 23 and the capillary 22 and the focused spot of the fusion laser;

[0069] Step 5: The signal monitoring module monitors the sensor's interference signal in real time, and adjusts the optical fiber five-dimensional translation stage 16 and the sensitive unit three-dimensional translation stage 20 to change the relative angle and position between the capillary 22 with the pigtail and the sensitive unit 21 until the interference signal detected by the signal monitoring module is the strongest. The laser welding module then controls the output power and output time of the laser to achieve preliminary welding between the capillary 22 and the sensitive unit 21.

[0070] Step 6: After the initial fusion between the capillary 22 and the sensitive unit 21 is completed, the fiber clamp 17 is released, and the rotating stage 19 is controlled to rotate to drive the capillary 22 and the sensitive unit 21 to rotate, and the next fusion position between the capillary 22 and the sensitive unit 21 is fused.

[0071] Furthermore, step 6 specifically includes the following steps: after the preliminary welding between the capillary 22 and the sensitive unit 21 is completed, the optical fiber clamping part 17 is loosened, the rotating table 19 is controlled to rotate to drive the capillary 22 and the sensitive unit 21 to rotate, and the three-dimensional displacement table 15 of the base is controlled to move to achieve the alignment between the next welding position of the same circle between the optical fiber pigtail 23 and the capillary 22 and the focused spot of the welding laser, and the next welding position between the capillary 22 and the sensitive unit 21 is welded.

[0072] like Figure 6 As shown, in this embodiment, a third welding position 26 - 3 and a fourth welding position 26 - 4 are provided on the same circumference between the capillary 22 and the sensitive unit 21 . Through multiple welding positions, a stable connection between the capillary 22 and the sensitive unit 21 can be ensured.

[0073] In addition, four welding positions can be set between the capillary 22 and the sensitive unit 21 on the same circumference. Under the premise that the laser welding module outputs two beams of welding laser, two positions can be welded at a time, and the welding of all welding positions can be achieved by rotating the rotating table 19 once.

[0074] In summary, the present invention provides an integrated high-temperature optical fiber sensor coupling packaging device and method based on laser welding. The integrated coupling packaging method of homogeneous materials adopted for the entire sensor can solve the problems of low sensor measurement accuracy and poor stability caused by thermal stress mismatch between heterogeneous materials. At the same time, it can also get rid of the limitation of high-temperature glue on the operating temperature of the sensor, making in-situ high-precision sensing measurement at higher temperatures possible; it can realize the low-cost, fast and efficient preparation of high-temperature resistant, highly reliable and high-precision integrated optical fiber sensors, which are suitable for in-situ parameter detection in extreme environments in aerospace, petroleum exploration, non-destructive testing and other fields.

[0075] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An integrated high-temperature optical fiber sensor coupling packaging device based on laser welding, characterized in that: include: Laser welding module, motion control module and signal detection module; The laser welding module is used to provide welding laser to the motion control module, so that the tail end of the optical fiber pigtail (23) is welded and fixed to the sensitive unit (21); The motion control module comprises a base three-dimensional displacement stage (15), an optical fiber five-dimensional displacement stage (16), an optical fiber clamping member (17), a sensitive unit clamping member (18), a rotating platform (19) and a sensitive unit three-dimensional displacement stage (20); the optical fiber five-dimensional displacement stage (16) and the sensitive unit three-dimensional displacement stage (20) are fixed on the base three-dimensional displacement stage (15); the optical fiber clamping member (17) is fixed on the optical fiber five-dimensional displacement stage (16); the sensitive unit clamping member (18) is fixed on the rotating platform (19), and the rotating platform (19) is fixed on the sensitive unit three-dimensional displacement stage (20); the optical fiber clamping member (17) is used to clamp the optical fiber pigtail (23), and the sensitive unit clamping member (18) is used to clamp the sensitive unit (21); The optical fiber five-dimensional displacement stage (16) is used to cooperate with the sensitive unit three-dimensional displacement stage (20) to achieve alignment between the sensitive unit (21) and the end of the optical fiber pigtail (23); the base three-dimensional displacement stage (15) is used to achieve alignment between the sensor welding position and the focused spot of the welding laser; the rotating stage (19) is used to rotate the sensitive unit clamping member (18) in a plane perpendicular to the direction of the optical fiber pigtail (23) to achieve switching of the welding position; The signal detection module includes a detection light source (12), a circulator (13) and a spectrometer (14), wherein the detection light source (12) is connected to the optical fiber pigtail (23) through the circulator (13), and the detection laser output by the detection light source (12) is transmitted to the sensitive unit (21) through the circulator (13) and the optical fiber (13), and is reflected back and forth between the sensitive unit (21) and the end face of the optical fiber pigtail (23) to form a double-beam interference; the interference signal is output through the optical fiber pigtail (23) and then transmitted to the spectrometer (14) through the circulator (13), and the spectral signal of the sensor is monitored in real time by the spectrometer (14); The laser welding module comprises: a carbon dioxide laser (1), a controller (2), a first light guide unit, a first variable magnification beam expander (6) and a first focusing lens (7), wherein the controller (2) is used to adjust the power and time of the laser output by the carbon dioxide laser (1); the laser output by the carbon dioxide laser (1) is incident and focused to the welding position after passing through the first light guide unit, the first variable magnification beam expander (6) and the first focusing lens (7); the first variable magnification beam expander (6) is used to adjust the laser beam spot size, and the first focusing lens (7) is used to focus the laser beam; The laser welding module further comprises a beam splitter prism (5), a second light guide unit, a second variable magnification beam expander (10) and a second focusing lens (11). The laser light output by the carbon dioxide laser (1) is incident on the beam splitter prism (5) after passing through the first light guide unit, and is divided into two beams by the beam splitter prism (5). One beam is incident on and focused to a welding position after passing through the first variable magnification beam expander (6) and the first focusing lens (7), and the other beam is incident on and focused to another welding position after passing through the second light guide unit, the second variable magnification beam expander (10) and the second focusing lens (11).

2. The integrated high-temperature optical fiber sensor coupling and packaging device based on laser welding according to claim 1, characterized in that: The first light guiding unit and the second light guiding unit each include two 45° reflecting mirrors.

3. The integrated high-temperature optical fiber sensor coupling and packaging device based on laser welding according to claim 1, characterized in that: It also includes an electron microscope (24) and a display screen (25), wherein the electron microscope (24) is connected to the display screen and is used to observe the welding position and welding state of the sensor in real time.

4. The integrated high-temperature optical fiber sensor coupling and packaging device based on laser welding according to claim 1, characterized in that: The sensitive unit clamping member (18) is provided with a sensitive unit clamping area and a capillary clamping area; the capillary clamping area is used to fix the capillary, and the optical fiber five-dimensional displacement stage (16) is also used to move the tail end of the optical fiber pigtail (23) to achieve alignment between the optical fiber pigtail (23) and the capillary (22); the sensitive unit clamping area is used to fix the sensitive unit (21).

5. The integrated high-temperature optical fiber sensor coupling and packaging device based on laser welding according to claim 4, characterized in that: The sensitive unit clamping member (18) includes a U-shaped base (18-1), a first slideway (18-2) and a second slideway (18-3) are provided in the U-shaped base (18-1), a first slider (18-4) is provided on the first slideway (18-2), and a second slider (18-5) is provided on the second slideway (18-3), and a first lead screw (18-6) and a second lead screw (18-7) are provided on a side wall of the U-shaped base (18-1), the end of the first lead screw (18-6) contacts the first slider (18-4) and is used to push the first slider (18-4) to slide along the first slideway (18-2) and thereby fix the sensitive unit (21); the end of the second lead screw (18-7) contacts the second slider (18-5) and is used to push the second slider (18-5) to slide along the second slideway (18-3) and thereby fix the capillary (22).

6. The integrated high-temperature optical fiber sensor coupling and packaging device based on laser welding according to claim 1, characterized in that: The detection light source (12) is an ASE light source with a wavelength of 1550 nm.

7. An integrated high-temperature optical fiber sensor coupling packaging method based on laser welding, characterized in that: The coupling packaging device according to any one of claims 1 to 6 is implemented, comprising the following steps: Step 1: Clean the sensitive unit (21) and the capillary (22) and fix them to the sensitive unit clamping area and the capillary clamping area respectively, and cut the end face of the optical fiber pigtail (23) flat and fix it to the optical fiber clamping part (17); Step 2: Control the optical fiber five-dimensional displacement stage (16) to move, thereby inserting the optical fiber pigtail (23) into the capillary (22), and keeping the end face of the optical fiber flush with the end face of the capillary; Step 3: Control the base three-dimensional displacement stage (15) to move, so as to achieve alignment between the welding position between the optical fiber pigtail (23) and the capillary (22) and the focused spot of the welding laser; control the output power and output time of the laser welding module to achieve welding between the capillary (22) and the optical fiber pigtail (23); Step 4: After the capillary (22) and the optical fiber pigtail (23) are fused, the capillary (22) is taken out from the capillary clamping area, and the optical fiber five-dimensional displacement stage (16) is controlled to move to insert the capillary (22) into the sensitive unit (21); the base three-dimensional displacement stage (15) is controlled to move to achieve alignment between the fusion position between the optical fiber pigtail (23) and the capillary (22) and the focused spot of the fusion laser; Step 5: The interference signal of the sensor is monitored in real time by the signal monitoring module, and the optical fiber five-dimensional displacement stage (16) and the sensitive unit three-dimensional displacement stage (20) are adjusted to change the relative angle and position between the capillary (22) with the pigtail and the sensitive unit (21) until the interference signal detected by the signal monitoring module is the strongest; then, the output power and output time of the laser output by the laser welding module are controlled to achieve preliminary welding between the capillary (22) and the sensitive unit (21); Step 6: After the initial fusion splicing between the capillary (22) and the sensitive unit (21) is completed, the optical fiber clamp (17) is released, and the rotating table (19) is controlled to rotate to drive the capillary (22) and the sensitive unit (21) to rotate, and the next fusion splicing position between the capillary (22) and the sensitive unit (21) is fused.

8. The integrated high-temperature optical fiber sensor coupling and packaging method based on laser welding according to claim 7, characterized in that: The step 3 specifically includes the following steps: Step 3.1: Control the base three-dimensional displacement stage (15) to move, so as to achieve alignment between the first welding position between the optical fiber pigtail (23) and the capillary (22) and the focused spot of the welding laser; control the output power and output time of the laser welding module to achieve welding between the capillary (22) and the optical fiber pigtail (23); Step 3.2: Control the base three-dimensional displacement stage (15) to move along the axial direction of the optical fiber pigtail (23) to achieve alignment between the next axial welding position between the optical fiber pigtail (23) and the capillary (22) and the focused spot of the welding laser, and then control the output power and output time of the laser welding module to achieve welding between the capillary (22) and the optical fiber pigtail (23), and then repeat the above steps to achieve multi-position welding between the capillary (22) and the optical fiber pigtail (23); Said step 6 specifically comprises the following steps: after the initial fusion between the capillary (22) and the sensitive unit (21) is completed, the optical fiber clamping member (17) is loosened, the rotating platform (19) is controlled to rotate to drive the capillary (22) and the sensitive unit (21) to rotate, and the base three-dimensional displacement platform (15) is controlled to move to achieve alignment between the next fusion position of the same circle between the optical fiber pigtail (23) and the capillary (22) and the focused spot of the fusion laser, and the next fusion position between the capillary (22) and the sensitive unit (21) is fused.

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