CN115855228A - All-quartz optical fiber Fabry-Perot vibration sensor and preparation method of sensitive unit thereof - Google Patents

Abstract

The utility model discloses a full quartz fiber Fabry-Perot vibration sensor, including sensing unit and optic fibre, sensing unit is including the first quartz plate that stacks gradually, quartzy sensing diaphragm, and second quartz plate, be formed with the microcavity between first quartz plate and second quartz plate, quartzy sensing diaphragm includes the quality piece that suspends in the microcavity and has the light reflecting surface towards the second quartz plate, and diverge to the periphery by the quality piece and extend and a plurality of beam structure of being connected with first quartz plate and second quartz plate, the quality piece is responded to the vibration and takes place the displacement so that the distance between light reflecting surface and the optic fibre terminal surface changes in the microcavity, the second quartz plate has the hole that aligns with the center of light reflecting surface, the optic fibre is inserted in the hole. According to the present disclosure, there is provided an all-silica optical fiber fabry-perot vibration sensor capable of stably operating in a high-temperature environment.

Description

All-quartz optical fiber Fabry-Perot vibration sensor and preparation method of sensitive unit thereof

Technical Field

The disclosure relates to a preparation method of a full quartz optical fiber Fabry-Perot vibration sensor and a sensitive unit thereof.

Background

In recent years, the measurement requirement of vibration parameters under high-temperature severe environment widely exists in the military and civil fields, and the measurement of vibration is closely related to the safety of some production lives. The traditional piezoelectric type or eddy current type vibration sensor has the problems that the manufacturing material is not high-temperature resistant, the anti-interference capability is poor, the signal line heat conduction has adverse effect on a demodulation system and the like, and the high-precision vibration measurement is difficult to carry out in a high-temperature severe environment. An optical fiber type vibration sensor, such as an optical fiber Fabry-Perot type vibration sensor, generally senses vibration by a sensing unit based on an optical interference principle, and has the advantages of small volume, high sensitivity, corrosion resistance, electromagnetic interference resistance and the like. The sensing unit can be made of high-temperature-resistant materials, and the high temperature is not easy to influence the application of the optical interference principle, so that the optical fiber Fabry-Perot vibration sensor is suitable for vibration measurement in the high-temperature environment. In recent years, techniques for manufacturing the optical fiber fabry-perot vibration sensor mainly include MEMS techniques, chemical etching techniques, arc discharge techniques, laser processing techniques, and the like. However, the consistency of the sensors manufactured by using the chemical etching technology, the arc discharge technology and the laser processing technology is relatively poor, for example, the consistency of the sensitive units is low due to the inconsistency of the thickness and the effective radius of the sensitive membranes in different sensitive units, and the low-cost mass manufacturing of the optical fiber vibration sensor is difficult to realize.

The optical fiber vibration sensor manufactured by the MEMS technology has the advantages of high consistency of sensitive units and batch manufacturing. At present, a vibration sensor for Fabry-Perot fiber optics is reported abroad, wherein a Pyrex glass wafer and a silicon wafer are used for realizing batch manufacturing of the vibration sensor, and the vibration sensor can carry out vibration measurement in a high-temperature environment of 350 ℃, but due to the limitation of the characteristics of materials, the vibration sensor is difficult to realize vibration test in a higher-temperature environment. Moreover, because two materials with different thermal expansion coefficients are used for manufacturing the sensor, when the sensor works in a high-temperature environment, the use performance of the sensor is affected due to the mismatch of the thermal expansion coefficients of the different materials, which is also one of the reasons for limiting the application of the sensor at high temperature. In addition, in the connection method of the optical fiber and the sensitive unit, a common method at present is to use ultraviolet epoxy resin or a high-temperature-resistant adhesive, and introduce a bonding material into the vibration sensor which needs to work in a high-temperature environment will further influence the stability and the service life of the vibration sensor at high temperature.

Therefore, it is desirable to provide a vibration sensor capable of stably operating in a high temperature environment and a method for manufacturing the same.

Disclosure of Invention

The present disclosure has been made in view of the above-mentioned state of the art, and an object thereof is to provide an optical fiber fabry-perot vibration sensor capable of withstanding high temperatures and improving measurement accuracy, and a manufacturing method capable of improving the uniformity of a sensing unit.

To this end, the first aspect of the present disclosure provides an all-silica fiber fabry-perot vibration sensor, including a sensing unit and an optical fiber, where the sensing unit includes a first silica plate, a silica sensing diaphragm, and a second silica plate stacked in sequence, a microcavity is formed between the first silica plate and the second silica plate, the silica sensing diaphragm includes a mass block suspended in the microcavity and having a light reflection surface facing the second silica plate, and a plurality of beam structures divergently extending from the mass block to an outer periphery and connected to the first silica plate and the second silica plate, the mass block is displaced in the microcavity by sensing vibration so as to change a distance between the light reflection surface and an end face of the optical fiber, the second silica plate has a hole aligned with a center of the light reflection surface, and the optical fiber is inserted into the hole.

In the all-silica optical fiber Fabry-Perot vibration sensor related to the first aspect of the disclosure, the composition of the sensing unit is all-silica material, the softening point of the silica glass material is as high as 1730 ℃, and the silica glass material is acid and alkali corrosion resistant, compared with the materials commonly used at present for manufacturing the optical fiber Fabry-Perot vibration sensor, such as metal, pyrex glass, silicon, sapphire, siC and the like, the silica glass material has a lower thermal expansion coefficient, and is a good material for manufacturing the high-temperature vibration sensor. In addition, this disclosure is through setting up the quality piece that has the light reflection face, and by a plurality of beam structures that the quality piece diverged to the periphery and extended, when optic fibre Fabry-Perot vibration sensor measured and made the quality piece take place the displacement in the vibration environment, retrain the quality piece at the periphery through a plurality of beam structures, can make and keep highly parallel between the light reflection face of quality piece (one of them leaded light face in Fabry-Perot cavity) and the other leaded light face in Fabry-Perot cavity, perpendicular to leaded light face and the incident light has high coincidence degree when reflecting between two leaded light faces in Fabry-Perot cavity, thereby can improve the intensity of the interference optical signal that forms when light reflects between two leaded light faces in Fabry-Perot cavity. Thereby, when the vibration is measured based on the interference light signal, the accuracy of the measurement can be improved.

In the all-silica fiber fabry-perot vibration sensor according to the first aspect of the present disclosure, the hole may be a through hole, and light entering the microcavity via the optical fiber may be reflected between the light reflecting surface and the end face of the optical fiber. Under the condition, the hole is set to be the through hole, the depth of the optical fiber can be conveniently adjusted, and therefore the initial cavity length of the Fabry-Perot cavity can be conveniently adjusted.

In addition, in the all-silica fiber fabry-perot vibration sensor according to the first aspect of the present disclosure, optionally, the hole is a counter bore, and light entering the micro-cavity through the optical fiber can be reflected by the light reflecting surface and the inner surface of the second silica plate. In this case, the light reflecting surface and the inner surface of the second quartz plate constitute two light guide surfaces of the fabry-perot chamber, so that the constancy of the initial chamber length of the fabry-perot chamber can be improved.

In the all-silica optical fiber fabry-perot vibration sensor according to the first aspect of the present disclosure, it is preferable that the first silica plate has a first groove facing the second silica plate, the second silica plate has a second groove facing the first silica plate, the first groove and the second groove cooperate to form the microcavity, and a projection is performed along a stacking direction of the first silica plate, the silica sensitive membrane, and the second silica plate, and the first groove and the second groove coincide. Therefore, a displacement space can be conveniently provided for the mass block through the matching of the first groove and the second groove.

In addition, in the all-silica fiber fabry-perot vibration sensor according to the first aspect of the present disclosure, it is preferable that the plurality of beam structures extend divergently from four sides of the mass block, respectively, in a projection along a stacking direction of the first silica plate, the silica sensitive membrane, and the second silica plate. Therefore, when the mass block displaces, the mass block is restrained by the beam structures, and high parallelism can be kept between the light reflecting surface of the mass block and the other light guide surface of the Fabry-Perot cavity.

In addition, in the all-silica fiber fabry-perot vibration sensor according to the first aspect of the present disclosure, optionally, the mass block further includes a joint portion surrounding an outer periphery of the mass block and having a ring shape, the beam structure connects the mass block and the joint portion, and the joint portion is sandwiched between the first silica piece and the second silica piece. Therefore, the beam structure can be clamped by the first quartz plate and the second quartz plate more stably.

In the all-silica optical fiber fabry-perot vibration sensor according to the first aspect of the present disclosure, the sensor may further include a boss provided on the second silica plate and integrally formed with the second silica plate, the boss may have a hollow portion communicating with the hole and coaxial with the hole, and an inner diameter of the hollow portion may be equal to an aperture diameter of the hole. Therefore, the alignment and fixation of the optical fiber can be facilitated through the boss.

In addition, in the all-silica optical fiber fabry-perot vibration sensor according to the first aspect of the present disclosure, optionally, a silica tube having a size matching a size of the hole and inserted into the hole, an optical fiber having a size matching a size of a lumen of the silica tube and inserted into the lumen of the silica tube, and the silica tube and the optical fiber, and the silica tube and the second silica piece are fused by a CO2 laser fusion method is further included. Thus, the welding of the optical fiber to the sensitive unit can be facilitated by the quartz tube.

In the all-silica optical fiber fabry-perot vibration sensor according to the first aspect of the present disclosure, the first silica plate, the silica sensitive membrane, and the second silica plate may be bonded to each other by bonding. Therefore, the first quartz piece, the quartz sensitive membrane and the second quartz piece can form the all-quartz sensitive unit with high adhesion degree by the bonding method.

The second aspect of the present disclosure provides a high-consistency preparation method for a sensing unit of an all-silica optical fiber fabry-perot vibration sensor, comprising the following steps: preparing a first quartz glass wafer having opposing upper and lower surfaces, a second quartz glass wafer having opposing upper and lower surfaces, and a third quartz glass wafer having opposing upper and lower surfaces; polishing the upper surface of the first quartz glass wafer, polishing the lower surface of the second quartz glass wafer, and polishing the upper surface and the lower surface of the third quartz glass wafer; manufacturing a plurality of first grooves on the upper surface of the first quartz glass wafer in a preset distribution mode; manufacturing a plurality of second grooves on the lower surface of the second quartz glass wafer in the preset distribution mode; manufacturing a plurality of holes on the second quartz glass wafer in the preset distribution mode; fabricating a plurality of beam mass structures on the third quartz glass wafer in the predetermined distribution manner; combining the upper surface of the first quartz glass wafer with the lower surface of the third quartz glass wafer and combining the lower surface of the second quartz glass wafer with the upper surface of the third quartz glass wafer in such a way that the first groove, the second groove and the beam mass are coaxial to form a laminated body, and cutting the laminated body to obtain a plurality of sensitive units.

In the batch preparation method, the first quartz glass wafer, the second quartz glass wafer and the third quartz glass wafer are processed to obtain the plurality of sensitive units, so that the material consistency of each sensitive unit can be improved; in addition, the first quartz glass wafer, the third quartz glass wafer and the second quartz glass wafer are combined in a coaxial mode through the first grooves, the beam mass block structures and the second grooves to form a laminated body, the grooves of the laminated body are cut to obtain the sensitive units, and the consistency of the sensitive membranes of the sensitive units can be improved. Therefore, the consistency of the sensitive units can be improved, and the consistency of the optical fiber Fabry-Perot vibration sensor can be improved.

According to the present disclosure, it is possible to provide an optical fiber Fabry-Perot vibration sensor that improves measurement accuracy and a manufacturing method that improves the uniformity of a sensing unit.

Drawings

Fig. 1 is a schematic diagram of an application scenario of a vibration sensor according to an example of the present disclosure.

Fig. 2 is a schematic view of the overall appearance of a vibration sensor according to an example of the present disclosure.

Fig. 3a is an exploded view of a vibration sensor according to an example of the present disclosure from a first perspective.

Fig. 3b is an exploded view of a vibration sensor according to examples of the present disclosure from a second perspective.

Fig. 4a is a schematic diagram of a through-hole of a sensitive cell according to an example of the present disclosure.

Fig. 4b is a schematic view of a counterbore of a sensitive cell according to an example of the present disclosure.

Fig. 5a is a schematic view of a fiber insertion sensitive unit according to an example of the present disclosure.

FIG. 5b is a schematic view of another embodiment of a fiber insertion sensitive unit according to examples of the present disclosure.

Figure 6a is a schematic view of a mass and beam structure according to an example of the present disclosure.

Figure 6b is a schematic view of another embodiment of a mass and beam structure according to examples of the present disclosure.

Fig. 7 is a schematic illustration of a flow chart of a method of making a high uniformity sensitive cell in accordance with an example of the present disclosure.

Fig. 8a is a schematic view of a first, second, and third quartz glass wafer of raw material according to an example of the present disclosure.

Fig. 8b is a schematic top view of a first quartz glass wafer, a second quartz glass wafer, and a third quartz glass wafer after processing according to an example of the present disclosure.

Fig. 8c is a schematic elevation view of a first quartz glass wafer, a second quartz glass wafer, and a third quartz glass wafer after processing according to an example of the present disclosure.

Figure 8d is a schematic view of a laminate according to examples of the present disclosure.

Fig. 8e is a schematic view of fabricating a plurality of bosses on a laminate according to an example of the present disclosure.

Fig. 9 is a schematic perspective view of a sensing unit according to an example of the present disclosure.

Detailed Description

Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. In the following description, the same components are denoted by the same reference numerals, and redundant description thereof is omitted. The drawings are schematic and the ratio of the dimensions of the components and the shapes of the components may be different from the actual ones.

It is noted that the terms "comprises" and "comprising," and any variations thereof, in this disclosure, such that a process, method, system, article, or apparatus that comprises or has a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include or have other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.

Embodiments of the present disclosure relate to an optical fiber Fabry-Perot vibration sensor capable of improving measurement accuracy. Embodiments of the present disclosure also relate to a method for manufacturing a sensing unit of the optical fiber Fabry-Perot vibration sensor. In this embodiment, the optical fiber fabry-perot high-temperature vibration sensor may be simply referred to as a vibration sensor, and the preparation method of the sensing unit may be simply referred to as a preparation method. With the vibration sensor of the present embodiment, the measurement accuracy of the vibration sensor can be further improved. By the preparation method of the embodiment, the consistency of the sensitive units of the vibration sensor can be improved, so that the consistency of the vibration sensor can be improved.

In this embodiment, the vibration sensor may include a sensing unit and an optical fiber. The sensing unit may comprise a fabry-perot chamber with two light guiding surfaces. After light enters the Fabry-Perot cavity through optical fiber transmission, the light can be reflected between the two light guide surfaces of the Fabry-Perot cavity and overlapped to form an interference light signal. By analyzing the interference light signal, the distance between the two light guide surfaces, namely the cavity length of the Fabry-Perot cavity, can be obtained.

In this embodiment, the fabry-perot cavity may be an optical resonant cavity composed of two light guide surfaces that are oppositely disposed, parallel to each other, and have a predetermined distance, light may be reflected between the two light guide surfaces of the fabry-perot cavity to form an interference light signal, and the interference light signal and the distance between the two light guide surfaces have a corresponding relationship. When the distance between two light guide surfaces of the Fabry-Perot cavity changes, the cavity length of the corresponding Fabry-Perot cavity also changes, and information carried by interference optical signals also correspondingly changes.

In this embodiment, the vibration sensor may be installed in a high-temperature environment to detect vibration information (for example, detect vibration information of an aircraft engine), the vibration sensor may obtain a change condition of an external mechanical parameter (acceleration, speed, displacement, etc.) through the sensing unit, convert the change condition of the mechanical parameter into change information of an interference optical signal according to the fabry-perot cavity interference principle, and demodulate the interference optical signal through the optical wave demodulation device to obtain a measurement result of the vibration.

Fig. 1 is a schematic view of an application scenario of a vibration sensor 1 according to an example of the present disclosure.

In some examples, referring to fig. 1, when the vibration sensor 1 is in operation, an optical signal (i.e., light) may be emitted from the light source 3 and enter the fabry-perot cavity of the vibration sensor 1, a portion of the optical signal (also referred to as a first reflected optical signal) may be reflected at the end surface of the optical fiber, another portion of the optical signal may be incident on the light reflecting surface of the mass block 160 via the fabry-perot cavity, and reflected between the end surface of the optical fiber (one light guiding surface of the fabry-perot cavity) and the light reflecting surface (another light guiding surface of the fabry-perot cavity), and the reflected optical signal (also referred to as a second reflected optical signal) may be transmitted back to the end surface of the optical fiber and coupled into the optical fiber 20. Thereby, the first reflected light signal and the second reflected light signal interfere with each other to form an interference light signal. The interference light signal can be transmitted to the light wave demodulation device 7 through the optical fiber 20, and the cavity length of the fabry-perot cavity can be obtained by demodulating the interference light signal through the light wave demodulation device 7. In this case, when the external mechanical parameter changes, the mass block 160 is displaced due to the vibration, so as to change the cavity length of the fabry-perot cavity, and thus the interference optical signal changes. At this time, the interference light signal is demodulated by the light wave demodulation device 7, so that the change information of the Fabry-Perot cavity length can be obtained, and finally the measurement result of the vibration is obtained.

In some examples, the intensity of the interference light signal acquired through the fabry perot cavity may have a positive correlation with the measurement of the vibration acquired based on the interference light signal. For example, the stronger the intensity of the interfering light signal, the more accurate the measurement of the vibration is obtained.

Fig. 2 is a schematic view of the overall appearance of the vibration sensor 1 according to the example of the present disclosure. Fig. 3a is an exploded view of a vibration sensor 1 according to an example of the present disclosure from a first perspective. Fig. 3b is an exploded view of the vibration sensor 1 according to the example of the present disclosure from a second perspective.

In the present embodiment, the vibration sensor 1 may include a sensing unit 10 and an optical fiber 20 (see fig. 2). In some examples, the sensing unit 10 may include a first quartz plate 12, a quartz sensing diaphragm 16, and a second quartz plate 14, which are sequentially stacked. In some examples, the first quartz plate 12, the quartz sensitive diaphragm 16 and the second quartz plate 14 may be bonded by a bonding method. In this case, the first quartz plate 12, the quartz sensitive diaphragm 16 and the second quartz plate 14 can be formed into an all-quartz sensitive unit with high adhesion degree by a bonding method.

In some examples, a microcavity may be formed between first quartz sheet 12 and second quartz sheet 14.

In some examples, first quartz plate 12 may have first grooves 602 and second quartz plate 14 may have second grooves 801 (see fig. 3a and 3 b). In some examples, first indentation 602 can face second quartz sheet 14 and second indentation 801 can face first quartz sheet 12, whereby first indentation 602 and second indentation 801 can cooperate to form a microcavity. In some examples, first recess 602 and second recess 801 may coincide to form a microcavity, as projected along the stacking direction of first quartz sheet 12, quartz sensitive diaphragm 16, and second quartz sheet 14. Thereby, a space for displacement can be provided for the mass 160 (described in detail later).

In some examples, the quartz sensitive diaphragm 16 may include a mass 160 and a plurality of beam structures 162 (see fig. 3a and 3 b). In some examples, plurality of beam structures 162 may include beam structure 162a, beam structure 162b, beam structure 162c, and beam structure 162d.

In some examples, the mass 160 may be suspended from the microcavity. In some examples, the mass 160 may be displaced within the microcavity in response to vibrations.

In some examples, the mass 160 may have a light reflective surface. The light reflecting surface may face the second quartz plate 14.

In some examples, a plurality of beam structures 162 may extend divergently from the mass 160 toward the outer periphery. In some examples, a plurality of beam structures 162 may be formed at the outer periphery of the mass 160 and extend divergently toward the outer periphery of the mass 160. Thereby, the plurality of beam structures 162 can be made to constrain the mass 160 at the outer periphery of the mass 160.

In some examples, a plurality of beam structures 162 may be connected with first quartz sheet 12 and second quartz sheet 14. In some examples, a plurality of beam structures 162 may extend from the mass 160 diverging to the periphery to connect with the first quartz plate 12 and the second quartz plate 14. In this case, the mass 160 is supported by the plurality of beam structures 162, so that the mass 160 is uniformly suspended in the microcavity.

In some examples, plurality of beam structures 162 may be connected to first quartz sheet 12 and second quartz sheet 14 by being sandwiched by first quartz sheet 12 and second quartz sheet 14. In this case, when the mass block 160 is displaced, the beam structures 162 constrain the mass block 160 at the outer periphery, so that the light reflection surface (one of the light guide surfaces of the fabry-perot cavity) of the mass block 160 and the other light guide surface of the fabry-perot cavity have a high degree of parallelism.

In some examples, referring to fig. 3a or 3b, the mass 160 may further include a joint 164. In some examples, the engagement portion 164 may be annular. The joint 164 may surround the outer periphery of the mass 160.

In some examples, a beam structure 162 may connect the mass 160 and the junction 164. In some examples, one end of the plurality of beam structures 162 may be connected to the mass 160 and the other end may be connected to the joint 164.

In some examples, joint 164 may be clamped by first quartz sheet 12 and second quartz sheet 14. This enables the beam structure 162 to be more stably sandwiched between the first quartz plate 12 and the second quartz plate 14.

As described above, the vibration sensor 1 according to the present embodiment may further include the optical fiber 20. The optical fiber 20 may be used to transmit light. In some examples, the optical fiber 20 may have a fiber end face. The fiber end face may be one in which the optical fiber 20 is cut flat.

In some examples, second quartz sheet 14 may have holes. The optical fiber 20 can be inserted into the hole. In some examples, the optical fiber 20 inserted into the aperture may cause light to enter the microcavity perpendicular to the light-reflecting surface of the mass 160. In some examples, the aperture may be centrally aligned with the light reflective surface of the mass 160. In this case, the light reflecting surface can be made to receive and reflect more light entering the microcavity, thereby facilitating the formation of a stronger interference light signal.

Fig. 4a is a schematic diagram of a through hole 144a of a sensing unit 10 according to an example of the present disclosure. Fig. 4b is a schematic view of a counterbore 144b of the sensing unit 10 according to an example of the present disclosure. Fig. 5a is a schematic view of an optical fiber 20 inserted into a sensitive unit 10 according to an example of the present disclosure. Fig. 5b is a schematic view of another embodiment of an optical fiber 20 inserted into a sensitive unit 10 according to an example of the present disclosure.

In some examples, referring to fig. 4a, the holes on second quartz sheet 14 may be fabricated as through holes 144a. In some examples, the fiber end face may be parallel to the light reflecting face after the fiber 20 is inserted into the through hole 144a. In some examples, the fiber end face and the light reflecting surface may be a predetermined distance apart. Therefore, the end face of the optical fiber and the light reflecting surface can form a Fabry-Perot cavity. In this case, the displacement of the mass 160 in the microcavity due to the vibration can change the distance between the end face of the optical fiber and the light reflecting surface. Thereby, the cavity length of the Fabry-Perot cavity can be changed.

In some examples, the predetermined distance between the end face of the optical fiber and the light reflecting surface after the optical fiber 20 is inserted into the through hole 144a may be 0.6mm, 0.8mm, 1.0mm, or 1.2mm. Preferably, the predetermined distance is 1.0mm. In this case, the depth of insertion of the optical fiber 20 can be conveniently adjusted by making the hole as a through hole, so that the initial cavity length of the fabry-perot cavity can be conveniently adjusted.

In some examples, the through-hole 144a may be aligned with a center of the light reflecting surface. In some examples, light entering the microcavity via the fiber 20 can be reflected between the center of the light reflecting surface and the end face of the fiber.

In some examples, referring to FIG. 4b, the hole in second quartz sheet 14 may be fabricated as a counterbore 144b. The counterbore 144b may be optically transparent. In some examples, the fiber end face may conform to the bottom surface of the counterbore 144b after the fiber 20 is inserted into the counterbore 144b.

In some examples, light transmitted via the optical fiber 20 may enter the microcavity through a bottom surface of the counterbore 144b. In some examples, light entering the microcavity may be reflected between the light reflecting surface and the inner surface of second quartz plate 14, thereby forming a plurality of interference light signals. In this case, the light reflecting surface and the inner surface of the second quartz plate 14 constitute two light guide surfaces of the fabry-perot chamber, and thus the constancy of the initial chamber length of the fabry-perot chamber can be improved.

The process of forming the plurality of interference light signals when the hole on the second quartz plate 14 is the counterbore 144b is described in detail below.

A portion of the light transmitted in the optical fiber 20 is reflected at the end face of the optical fiber (also referred to as a first reflected light), a portion of the light is reflected at the bottom of the counterbore 144b (also referred to as a second reflected light), and another portion of the light can enter the microcavity via the counterbore 144b and be reflected between the light reflecting surface and the inner surface of the second quartz plate 14. The reflected light within the microcavity (also referred to as the third reflected light) may be transmitted back through the counterbore 144b to the fiber end face and coupled into the fiber 20. In this case, the first reflected light, the second reflected light, and the third reflected light interfere with each other, whereby a plurality of interference light signals can be formed. This enables a strong interference optical signal to be obtained.

In some examples, referring to fig. 5a, the inner diameter of the hole in second quartz plate 14 may match the outer diameter of optical fiber 20. In some examples, the inner diameter of the hole in second quartz plate 14 may be slightly larger than the outer diameter of optical fiber 20. In this case, the optical fiber 20 can be fixedly connected to the sensing unit 10 by inserting the optical fiber 20 into the hole and fixing it therein.

In some examples, referring to fig. 5b, the vibration sensor 1 may further comprise a quartz tube 24. The quartz tube 24 may be inserted into a hole in the second quartz plate 14. In some examples, the size of the component of the quartz tube 24 inserted into the bore may match the size of the bore. Specifically, the inner diameter of the hole in the second quartz plate 14 may be matched with the outer diameter of the member of the quartz tube 24 inserted into the hole.

In some examples, the inner diameter of the hole in the second quartz plate 14 may be slightly larger than the outer diameter of the part of the quartz tube 24 inserted into the hole. In some examples, the quartz tube 24 may be inserted into the bore, and the quartz tube 24 may be secured in the bore. Thereby, the coupling of the quartz tube 24 with the sensing unit 10 can be achieved.

In some examples, the dimensions of the optical fiber 20 may match the dimensions of the lumen of the quartz tube 24. Specifically, the inner diameter of the quartz tube 24 may be matched to the outer diameter of the optical fiber 20, whereby the optical fiber 20 can be fixed to the quartz tube 24 by fitting the lumen of the quartz tube 24 to the optical fiber 20.

In some examples, the inner diameter of the lumen of the quartz tube 24 may be slightly larger than the outer diameter of the optical fiber 20. In some examples, the optical fiber 20 may be inserted into the lumen of the quartz tube 24, and the optical fiber 20 may be secured in the lumen of the quartz tube 24.

In some examples, the quartz tube 24 may be inserted into the bore before the optical fiber 20 is inserted into the quartz tube 24. In this case, the alignment and fixation of the optical fiber 20 is facilitated by the quartz tube 24 being fixed in the hole first.

In some examples, the quartz tube 24 and the optical fiber 20 may be through CO ₂ The laser welding method performs welding. In some examples, the quartz tube 24 and the second quartz plate 14 may be passed through the CO ₂ The laser welding method performs welding to achieve bonding of the quartz tube 24 with the sensing unit 10. In this case, the welding of the optical fiber 20 to the sensitive unit 10 can be facilitated by the quartz tube 24.

In some examples, the optical fiber 20 may be a bare fiber. The bare optical fiber may be embedded in the quartz tube 24. In this case, the bare fiber can be fixedly connected to the sensing unit 10 by inserting the quartz tube 24 into the hole and then bonding it to the second quartz plate 14 through CO2 laser welding.

In some examples, referring to fig. 5a or 5b, the vibration sensor 1 may further include a boss 142. In some examples, boss 142 may be provided to second quartz sheet 14. In some examples, boss 142 may be disposed on a side of second quartz plate 14 away from the microcavity. In some examples, boss 142 may be integrally formed with second quartz sheet 14.

In some examples, the boss 142 may have a hollow. In some examples, the hollow portion may be in communication with the aperture of second quartz piece 14. In some examples, the hollow may be in coaxial communication with the aperture of second quartz plate 14. In some examples, the inner diameter of the hollow portion may be the same as the bore diameter of the bore. In this case, the optical fiber 20 or the quartz tube 24 inserted into the hole can be aligned by the boss 142. Thereby facilitating light entering the microcavity in a manner perpendicular to second quartz plate 14.

In some examples, the optical fiber 20 inserted into the hole may be fusion-bonded with the boss 142. In some examples, the optical fiber 20 may be fusion bonded to the boss 142 by way of a high temperature fusion splice. In some examples, the optical fiber 20 and the boss 142 may pass through the CO ₂ The laser welding method is used for welding and combining. In this case, a firm connection between the optical fiber 20 and the sensing unit 10 can be formed by the boss 142, so that the tight coupling of the optical fiber 20 and the sensing unit 10 can be achieved.

In some examples, the quartz tube 24 inserted into the bore may be fusion bonded to the boss 142. In some examples, quartz tube 24 and boss 142 may be passed through CO ₂ The laser welding method is used for welding and combining. Thereby, the quartz tube 24 can be tightly coupled to the sensing unit 10.

In some examples, boss 142 may be obtained by machining the side of second quartz plate 14 remote from the microcavity by numerical control machining (CNC machining). In some examples, the boss 142 may be in the shape of an elliptical cylinder, a prism (e.g., a quadrangular prism), or the like. Preferably, the boss 142 may be cylindrical.

In some examples, the boss 142 may be cylindrical. The height of the boss 142 may be 0.5mm to 1.5mm. Preferably, the height of the boss 142 is 1mm. In some examples, the boss 142 may have a diameter of 100 μm to 2.5mm.

In some examples, the fiber end face may be provided with an optical collimating element. In some examples, the optical collimating element may collimate the light output from the optical fiber 20, thereby facilitating entry of the light into the microcavity in a manner that is perpendicular to the light reflecting surface.

Fig. 6a is a schematic view of a mass 160 and a beam structure 162 according to examples of the present disclosure. Fig. 6b is a schematic diagram of another embodiment of a mass 160 and beam structure 162 in accordance with examples of the present disclosure.

In some examples, the plurality of beam structures 162 may extend divergently from four sides of the proof mass 160, respectively, as projected along the stacking direction of the first quartz plate 12, the quartz sensitive diaphragm 16, and the second quartz plate 14. In some examples, a plurality of beam structures 162 may extend outwardly diverging from four sides of the mass 160 to connect with the first and second quartz plates 12 and 14, respectively. In some examples, a plurality of beam structures 162 may extend divergently outward from four sides of the mass 160 to connect with the joints 164 (see fig. 6a or 6 b), respectively.

In some examples, the plurality of beam structures 162 may be evenly distributed on four sides of the mass 160. In some examples, a plurality of beam structures 162 may be formed on four sides of the mass 160 in an evenly distributed manner. In some examples, one end of the plurality of beam structures 162 may be connected to four sides of the mass 160 in a uniformly distributed manner, and the other end may be connected with the joint 164. This enables the plurality of beam structures 162 to exert a uniform restraining action on the mass block 160.

In the following, the distribution of the plurality of beam structures 162 will be described by taking the number of beam structures 162 as four as an example.

In some examples, referring to fig. 6a, the beam structure 162 may be elongated. One end of the four beam structures 162 may be connected to four sides of the mass 160 in an evenly distributed manner, and the other end of the four beam structures 162 may be connected with the joint 164. In this case, the mass 160 is uniformly suspended in the micro-cavity by uniformly supporting the mass 160 by the four beam structures 162. Therefore, when the mass block 160 displaces, the light reflecting surface of the mass block 160 can be used as one of the light guide surfaces of the Fabry-Perot cavity and can keep highly parallel to the other light guide surface of the Fabry-Perot cavity due to the uniform constraint effect of the four beam structures 162 on the mass block 160. In this case, the light incident perpendicularly to the light reflecting surface has a high overlap ratio when reflected between the two light guiding surfaces of the fabry-perot cavity, and the intensity of the interference light signal formed when the light is reflected between the two light guiding surfaces of the fabry-perot cavity can be increased. Thereby, when the vibration is measured based on the interference light signal, the accuracy of the measurement can be improved.

In some examples, four elongated beam structures 162 may be formed on four sides of the mass 160 in a uniformly distributed manner, and two adjacent beam structures 162 may be connected to four sides of the mass 160 in a mutually orthogonal manner.

In some examples, the plurality of beam structures 162 may also be L-shaped (see fig. 6 b). In some examples, a plurality of L-shaped beam structures 162 may be formed on four sides of the mass 160 in an evenly distributed manner.

In some examples, a plurality of L-shaped beam structures 162 may extend diverging outwardly from four sides of the mass 160 to connect with the first and second quartz plates 12 and 14, respectively. In some examples, a plurality of L-shaped beam structures 162 may extend diverging outwardly from four sides of the mass 160 to connect with the joints 164, respectively.

In some examples, the elongated beam structures 162 and the L-shaped beam structures 162 may each induce a different vibration frequency to the mass 160. Thus, the vibration sensor 1 can have different resonance frequencies and sensitivities by changing the shape of the beam structure 162.

In some examples, the mass 160 may be made to sense different vibration frequencies by varying the dimensions of the beam structure 162.

In some examples, the joint 164 may be a ring-shaped rim. In some examples, the outer shape of joint 164 may be the same as the outer shape of first quartz sheet 12 and second quartz sheet 14 (e.g., square). The size of joint 164 may correspond to the size of first quartz plate 12 and second quartz plate 14. This enables the joint portion 164 to be sandwiched more sufficiently between the first quartz piece 12 and the second quartz piece 14.

In some examples, the joint 164 may be a square bezel. In some examples, the mass 160 may be square in shape. The mass 160 may be located in the center of the junction 164. Thereby, the mass 160 and the joint 164 can be made to form a structure like a Chinese character 'hui' (see fig. 6 a).

In some examples, the mass 160 may be square, diamond, circular, or oval. Preferably, the mass 160 may have a square shape. The side length of the square mass 160 may range from 2mm to 4mm, for example, 2.2mm, 2.4mm, 2.5mm, 2.6mm, 2.8mm, 3.0mm, 3.2mm, 3.4mm, 3.5mm, 3.6mm, or 3.8mm, and preferably, the side length of the square mass 160 is 3.0mm.

In some examples, the thickness of the mass 160 may range from 0.2mm to 0.4mm, and may take, for example, 0.22mm, 0.24mm, 0.25mm, 0.26mm, 0.28mm, 0.3mm, 0.32mm, 0.34mm, 0.35mm, 0.36mm, or 0.38mm. Preferably, the mass 160 has a thickness of 0.3mm.

In some examples, the beam structure 162 may be rectangular, with the length of the rectangular beam structure 162 ranging from 2.5mm to 3.5mm. For example, 2.6mm, 2.8mm, 3.0mm, 3.2mm, or 3.4mm may be taken. Preferably, the length of the beam structure 162 takes a value of 3mm. The width of the rectangular beam structure 162 ranges from 0.5mm to 1.3mm. For example, 0.6mm, 0.8mm, 1.0mm, or 1.2mm may be taken. Preferably, the width of the beam structure 162 is 1.0mm.

As described above, in some examples, the thickness of the beam structure 162 may be consistent with the thickness of the mass 160. The present disclosure is not so limited and in other examples, the thickness of the beam structure 162 may not be consistent with the thickness of the mass 160.

Fig. 7 is a schematic illustration of a flow chart of a method of making a high consistency sensitive cell 10 according to an example of the present disclosure. Fig. 8a is a schematic illustration of a first quartz glass wafer 600, a second quartz glass wafer 800, and a third quartz glass wafer 900, which are unprocessed, according to an example of the present disclosure.

Fig. 8b is a schematic depression angle view of the first quartz glass wafer 600, the second quartz glass wafer 800 and the third quartz glass wafer 900 after processing according to the disclosed example. Fig. 8c is a schematic elevation view of a first quartz glass wafer 600, a second quartz glass wafer 800 and a third quartz glass wafer 900 after processing according to an example of the present disclosure. Figure 8d is a schematic view of a laminate 1000 according to examples of the present disclosure. Fig. 8e is a schematic view of fabricating a plurality of bosses 142 on a laminate 1000 according to an example of the present disclosure.

In the present embodiment, referring to fig. 7, the preparation method may include the steps of: preparing a first quartz glass wafer 600, a second quartz glass wafer 800 and a third quartz glass wafer 900 (step S100); fabricating a plurality of grooves and positioning holes 604 on the first quartz glass wafer 600 (step S200); forming a plurality of grooves, a plurality of holes 802, and a plurality of positioning holes 804 on the second quartz glass wafer 800 (step S300); a plurality of beam mass structures 902 and positioning holes 904 are formed on a third quartz glass wafer 900 (step S400); sequentially bonding a first quartz glass wafer 600, a third quartz glass wafer 900, and a second quartz glass wafer 800 to form a laminate 1000 (step S500); fabricating a plurality of bosses 142 in the laminate 1000 (step S600); the laminated body 1000 is cut (step S700).

In step S100 of the present embodiment, referring to fig. 8a, a first quartz glass wafer 600 having opposite upper and lower surfaces is prepared, a second quartz glass wafer 800 having opposite upper and lower surfaces is prepared, and a third quartz glass wafer 900 having opposite upper and lower surfaces is prepared. It should be understood that terms such as "upper surface", "lower surface", and the like may be used to distinguish between different locations and should not be considered limiting.

In some examples, the upper surface of the first quartz glass wafer 600 may be polished. The lower surface of the second quartz glass wafer 800 may be polished. The upper and lower surfaces of the third quartz glass wafer 900 may be polished. In this case, the bonding between the upper surface of the first quartz glass wafer 600 and the lower surface of the third quartz glass wafer 900 can be facilitated by polishing the upper surface of the first quartz glass wafer 600 and the lower surface of the third quartz glass wafer 900. The bonding between the lower surface of the second quartz glass wafer 800 and the upper surface of the third quartz glass wafer 900 can be facilitated by polishing the lower surface of the second quartz glass wafer 800 and the upper surface of the third quartz glass wafer 900. Thereby facilitating the formation of a tightly bonded laminate 1000 (see fig. 8 d) by sequentially laminating the first quartz glass wafer 600, the third quartz glass wafer 900 and the second quartz glass wafer 800.

In some examples, the thickness of the first quartz glass wafer 600 may be 0.1mm to 2mm. In some examples, the thickness of the second quartz glass wafer 800 may be 0.5mm to 2mm. In some examples, the third quartz glass wafer 900 may have a thickness of 10 μm to 500 μm. As described above, in step S200 of this embodiment, referring to fig. 8b, a plurality of first grooves (in the embodiment shown in fig. 8b, one of the plurality of first grooves 602 is marked, and hereinafter referred to as a groove 602) may be formed on the upper surface of the first quartz glass wafer 600, and the plurality of grooves may be a groove array. In some examples, the grooves 602 in the groove array may be evenly distributed on the upper surface of the first quartz glass wafer 600. In some examples, the groove array can be fabricated based on a predetermined distribution pattern. The predetermined distribution may include at least the wheelbase between each groove 602.

In some examples, the positioning holes 604 of the first quartz glass wafer 600 may be located near the edge of the first quartz glass wafer 600, the positioning holes 604 may be through holes, and the number of the positioning holes 604 may be plural. For example, the number of locating holes 604 may be 2, 4, or 6, etc.

In some examples, the grooves 602 in the groove array may be cylindrical, elliptical cylindrical, or prismatic (e.g., quadrangular prismatic). In some examples, the grooves 602 in the array of grooves may preferably be quadrangular prism shaped. In some examples, the grooves 602 in the groove array may have the same side length. In some examples, the grooves 602 in the groove array may have the same depth.

In some examples, the grooves 602 in the groove array may be mass-produced on the upper surface of the first quartz glass wafer 600 by a micro-electro-mechanical system (MEMS) process, and the grooves 602 in the groove array may have a uniform depth by using the MEMS process. Thereby, it is advantageous to ensure the consistency of the sensitive unit 10. As described above, in step S300 of this embodiment, referring to fig. 8c, a plurality of second grooves 801 (in the embodiment shown in fig. 8c, one of the plurality of second grooves 801 is marked, and hereinafter referred to as a groove 801) are formed on the lower surface of the second quartz glass wafer 800, and the plurality of grooves may be a groove array. In some examples, the grooves 801 in the groove array may be evenly distributed on the lower surface of the second quartz glass wafer 800. In some examples, the groove array can be fabricated based on a predetermined distribution pattern that includes at least the wheelbase between each groove 801.

In some examples, the grooves 801 of the lower surface of the second quartz glass wafer 800 may be fabricated in the same manner as the grooves 602 of the upper surface of the first quartz glass wafer 600. Thus, the grooves 602 of the upper surface of the first quartz glass wafer 600 can be aligned with the grooves 801 of the lower surface of the second quartz glass wafer 800 to form micro-cavities.

In step S300 of this embodiment, referring to fig. 8b, a plurality of holes 802 and positioning holes 804 may be formed on the upper surface of the second quartz glass wafer 800. Specifically, a plurality of holes 802 and positioning holes 804 may be formed on the top surface of the second quartz glass wafer 800 at positions corresponding to the respective micro-cavities and positioning holes 604 of the first quartz glass wafer 600. In some examples, the plurality of wells 802 can be an array of wells (in the embodiment shown in fig. 8b, one of the wells 802 is labeled).

In some examples, the fabrication of the array of holes 802 may be based on a predetermined distribution pattern. The predetermined distribution may be the same as the predetermined distribution of the plurality of grooves 801. In this case, the groove array and the hole array are made based on the same predetermined distribution pattern so that each groove 801 of the second quartz glass wafer 800 can form a coaxial line with each hole 802.

In some examples, the positioning holes 804 of the second quartz glass wafer 800 may be close to the edge of the second quartz glass wafer 800, the positioning holes 804 may be through holes, and the number of the positioning holes 804 may be plural. For example, the number of positioning holes 804 may be 2, 4, 6, or the like.

In some examples, the holes 802 in the array of holes may be made in the upper surface of the second quartz glass wafer 800 by a laser cutting process. Additionally, in some examples, holes 802 in the array of holes may also be fabricated on the top surface of the second quartz glass wafer 800 by CNC machining.

In step S400 of this embodiment, referring to fig. 8b and 8c, a plurality of beam mass structures 902 and positioning holes 904 may be formed in the third quartz glass wafer 900. The plurality of beam mass structures may be an array of beam mass structures (in the embodiment shown in fig. 8b, one of the plurality of beam mass structures 902 is labeled, hereinafter referred to as beam mass structure 902).

In some examples, the beam mass structures 902 in the array of beam mass structures may be evenly distributed across the third quartz glass wafer 900. In some examples, fabrication of the array of beam-mass structures 902 may be based on a predetermined distribution including at least a center-to-center distance between each beam-mass structure 902. In this case, when the third quartz glass wafer 900 covers the groove 602 of the upper surface of the first quartz glass wafer 600 or the groove 801 of the lower surface of the second quartz glass wafer 800, the beam mass structure 902 can be made coaxial with the center line of the aforementioned groove.

In some examples, a microcavity may be formed between groove 602 of the upper surface of first quartz glass wafer 600 and groove 801 of the lower surface of second quartz glass wafer 800, and beam mass structure 902 may be placed within the microcavity. In some examples, the centerline of the beam mass structure 902 may be coaxial with the centerline of the quasi-microcavity.

In some examples, the beam proof mass structure 902 of the beam proof mass structure array may be fabricated on the third quartz glass wafer 900 using a femtosecond laser machining process. Specifically, the trajectory of the femtosecond laser ablation is controlled by computer programming, and a portion of the quartz material is removed by laser ablation to form a beam-mass structure 902. This can provide the beam mass structure 902 having a hollow structure.

The beam mass structure 902, which is prepared via a mass production method, may include a displacement portion and a plurality of connecting portions, the structure of the displacement portion may be the same as or similar to the mass 160 described herein, the structure of the connecting portions may be the same as or similar to the plurality of beam structures 162 described herein, and the structural relationship between the displacement portion and the connecting portions may also be the same as or similar to the structural relationship between the mass 160 and the plurality of beam structures 162 described herein.

In some examples, the positioning holes 904 of the third quartz glass wafer 900 may be made on the third quartz glass wafer 900 at positions corresponding to the positioning holes of the first quartz glass wafer 600 or the second quartz glass wafer 800.

In some examples, the positioning holes 904 of the third quartz glass wafer 900 may be near the edge of the third quartz glass wafer 900, the positioning holes 904 may be through holes, and the number of the positioning holes 904 may be plural. For example, the number of positioning holes 904 may be 2, 4, 6, or the like. In step S500 of the present embodiment, referring to fig. 8d, a first quartz glass wafer 600, a third quartz glass wafer 900 and a second quartz glass wafer 800 may be sequentially combined to form a laminated body 1000.

In some examples, in step S500, the upper surface of the first quartz glass wafer 600 and the lower surface of the third quartz glass wafer 900 may be sequentially bonded, and the lower surface of the second quartz glass wafer 800 and the upper surface of the third quartz glass wafer 900 may be sequentially bonded. Thereby, the first quartz glass wafer 600, the third quartz glass wafer 900, and the second quartz glass wafer 800 can form the laminated body 1000. In stack 1000, first groove 602, beam mass structure 902, and second groove 801 may be coaxial.

In some examples, in the laminate 1000, each groove 602 of the first quartz glass wafer 600 may be coaxial with each hole 802 of the second quartz glass wafer 800, respectively. For example, the groove 602 of the first quartz glass wafer 600 is coaxial with the hole 802 of the second quartz glass wafer 800.

In some examples, in the laminate 1000, each recess 602 of the first quartz glass wafer 600 may form a plurality of microcavities with each recess 801 of the second quartz glass wafer 800, respectively. The plurality of microcavities may be an array of microcavities.

In some examples, each beam mass structure 902 of the array of beam mass structures of the third quartz wafer 900 may be respectively coaxial with each microcavity of the array of microcavities. Thereby, the displacement portion of each beam mass structure 902 can be suspended at the center of each microcavity.

In some examples, the positioning holes 604, 904, and 804 may be aligned with each other during the sequential lamination of the first quartz glass wafer 600, the third quartz glass wafer 900, and the second quartz glass wafer 800 to form the laminate 1000. In this case, by aligning the positioning holes 604, 904, 804 with each other, it is possible to facilitate forming a plurality of micro-cavities by aligning the respective first grooves 602, 801 respectively after stacking, and to locate the displacement portions of the respective beam mass structures 902 at the centers of the respective micro-cavities respectively.

In some examples, the first quartz glass wafer 600, the third quartz glass wafer 900, and the second quartz glass wafer 800 may be bonded via thermal bonding to form the laminated body 1000. In some examples, the first quartz glass wafer 600, the third quartz glass wafer 900, and the second quartz glass wafer 800 may be bonded via high temperature thermocompression bonding or low temperature bonding to form the laminate 1000.

In some examples, in the stack 1000, the axes of the microcavities in the array of microcavities may be perpendicular to the upper surface of the first quartz glass wafer 600, and the axes of the holes 802 in the array of holes may also be perpendicular to the upper surface of the first quartz glass wafer 600.

In step S600 of the present embodiment, referring to fig. 8e, a plurality of bosses 142 may be formed in the laminate 1000. Specifically, a plurality of bosses 142 (in the embodiment shown in fig. 8e, one of the plurality of bosses 142 is marked, and hereinafter, referred to as a boss 142) may be formed at positions corresponding to the respective holes 802 on the upper surface of the second quartz glass wafer 800 of the laminate 1000. The plurality of bosses 142 may be an array of bosses.

In some examples, the bosses 142 in the boss array may be cylindrical bosses or prismatic bosses. In some examples, each boss 142 in the array of bosses may be coaxial with each corresponding aperture 802 in the array of apertures. The holes 802 in the array of holes may pass through the lands 142 in the array of lands.

In some examples, the mesas 142 in the array of mesas having the same height and the same diameter may be fabricated on the upper surface of the second quartz glass wafer 800 by CNC machining. Thereby, the uniformity of the sensitive cells 10 obtained via the laminate 1000 can be improved.

Fig. 9 is a schematic perspective view of a sensing unit 10 according to an example of the present disclosure.

As described above, in step S700 of the present embodiment, referring to fig. 9, the stacked body 1000 may be cut, thereby obtaining a plurality of sensitive cells 10. In some examples, the predetermined cutting diameter may be greater than the diameter of each groove and not greater than the wheelbase between adjacent holes 802.

In some examples, the laminate 1000 may be cut in a predetermined manner by CNC machining. This makes it possible to obtain the sensitive cells 10 having the same shape and the same size. In some examples, the sensing unit 10 may be cylindrical. In some examples, the sensitive cell 10 may have a prismatic shape (e.g., a quadrangular prism shape). Preferably, the sensing unit 10 may have a quadrangular prism shape.

In the present embodiment, a plurality of grooves having the same size and depth are formed in a predetermined distribution on the upper surface of the first quartz glass wafer 600 and the lower surface of the second quartz glass wafer 800, respectively, and a plurality of beam mass structures 902 having moving parts are formed in the same distribution on the third quartz glass wafer 900. The first quartz glass wafer 600, the third quartz glass wafer 900, and the second quartz glass wafer 800 are sequentially stacked by means of positioning holes (e.g., jig positioning or CCD positioning) to form a stacked body 1000. This enables the formation of a plurality of highly uniform fabry-perot cavities (e.g., uniform shape, uniform size, etc.). In this case, by cutting the stacked body 1000, a plurality of sensitive cells 10 having high uniformity can be obtained.

While the present disclosure has been described in detail above with reference to the drawings and examples, it should be understood that the above description is not intended to limit the disclosure in any way. Those skilled in the art can make modifications and variations to the present disclosure as needed without departing from the true spirit and scope of the disclosure, which fall within the scope of the disclosure.

Claims (10)

1. The utility model provides an all quartz fiber Fabry-Perot vibration sensor, its characterized in that includes sensing unit and optic fibre, the sensing unit is including the first quartz plate, quartzy sensing diaphragm and the second quartz plate that stack gradually first quartz plate with be formed with the microcavity between the second quartz plate, quartzy sensing diaphragm including suspension in the microcavity and have towards the quality piece of the light reflecting surface of second quartz plate and by the quality piece is to the outer week divergent extension and with first quartz plate with a plurality of beam structure that the second quartz plate is connected, the second quartz plate have with the hole that the center of light reflecting surface aimed at, optic fibre inserts the hole, optic fibre has the fiber end face, the quality piece is induced to vibrate and takes place the displacement in the microcavity so that the light reflecting surface with the distance between the fiber end face changes.

2. The all-silica fiber fabry-perot vibration sensor of claim 1, wherein the aperture is a through-hole, and light entering the microcavity via the fiber is reflected between the light reflecting surface and the fiber end face.

3. The all-silica fiber Fabry-Perot vibration sensor of claim 1, wherein said hole is a counter-bore, and light entering said microcavity via said fiber is reflected between said light-reflecting surface and an inner surface of said second silica plate.

4. The all-quartz fiber Fabry-Perot vibration sensor according to claim 1, wherein said first quartz plate has a first groove facing said second quartz plate, said second quartz plate has a second groove facing said first quartz plate, said first groove and said second groove cooperate to form said microcavity, and said first groove and said second groove coincide, as projected in a direction of lamination of said first quartz plate, said quartz sensitive membrane and said second quartz plate.

5. The all-silica fiber Fabry-Perot vibration sensor of claim 1, wherein the plurality of beam structures extend divergently from four sides of the mass respectively, as projected along a stacking direction of the first silica plate, the quartz sensitive membrane and the second silica plate.

6. The all-silica fiber Fabry-Perot vibration sensor of claim 1, wherein the mass further comprises a junction surrounding the outer periphery of the mass and having a ring shape, wherein the beam structure connects the mass and the junction, and wherein the junction is sandwiched by the first and second quartz plates.

7. The all-silica optical fiber Fabry-Perot vibration sensor according to claim 1, further comprising a boss provided to and integrally formed with the second quartz plate, the boss having a hollow portion communicating with the hole and coaxial with the hole, an inner diameter of the hollow portion being the same as an aperture of the hole.

8. The all-silica fiber Fabry-Perot vibration sensor according to claim 1, further comprising a silica tube having a size matching a size of the hole and inserted into the hole, the optical fiber having a size matching a size of a lumen of the silica tube and inserted into the lumen of the silica tube, the silica tube and the optical fiber, and the silica tube and the second silica plate passing CO ₂ And welding by a laser welding method.

9. The all-silica fiber Fabry-Perot vibration sensor of claim 1, wherein the first silica plate, the silica sensitive membrane and the second silica plate are bonded together.

10. A method for preparing a sensitive unit of an all-quartz optical fiber Fabry-Perot vibration sensor is characterized in that,

the method comprises the following steps:

preparing a first quartz glass wafer having opposing upper and lower surfaces, a second quartz glass wafer having opposing upper and lower surfaces, and a third quartz glass wafer having opposing upper and lower surfaces;

polishing the upper surface of the first quartz glass wafer, polishing the lower surface of the second quartz glass wafer, and polishing the upper surface and the lower surface of the third quartz glass wafer;

manufacturing a plurality of first grooves on the upper surface of the first quartz glass wafer in a preset distribution mode;

manufacturing a plurality of second grooves on the lower surface of the second quartz glass wafer in the preset distribution mode;

manufacturing a plurality of holes on the second quartz glass wafer in the preset distribution mode;

fabricating a plurality of beam mass structures on the third quartz glass wafer in the predetermined distribution manner;

bonding an upper surface of the first quartz glass wafer with a lower surface of the third quartz glass wafer and bonding a lower surface of the second quartz glass wafer with an upper surface of the third quartz glass wafer in such a manner that the first groove, the second groove, and the beam mass structure are coaxial to form a stacked body, and dicing the stacked body to obtain a plurality of the sensing units.

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