Tunable Fiber Scanner of All-Fiber Nonlinear Microscopic Imager and Manufacturing Method

Abstract

The present invention discloses a tunable fiber scanner for an all-fiber nonlinear microscopy imager, which includes a scanning optical fiber, a scanning component, and a driving component. A spiral adjuster is fixed at the front end of the scanning optical fiber; the scanning component includes a micro scanning square tube. The scanning optical fiber is fixed at the center position of the micro scanning square tube. The relative sliding between the scanning optical fiber and the fiber ferrule forms a fiber cantilever. The scanning optical fiber moves horizontally under the control of the spiral adjuster to obtain an adjustable fiber cantilever length; the driving component includes a piezoelectric ceramic driver arranged outside the scanner. The piezoelectric ceramic driver applies an amplified driving signal to the micro scanning square tube. The micro scanning square tube receives the amplified driving signal, drives the scanning optical fiber to perform scanning, and drives the fiber cantilever to perform resonant scanning. Compared with the prior art, the present invention combines the micro scanning square tube and the resonant scanning of the scanning optical fiber to achieve finely controllable resonant scanning for optical microscopy imaging equipment.

Description

Technical Field

[0001] The present invention relates to the fields of non-linear optical imaging and fiber scanning, and particularly to a four-piece assembled tunable piezoelectric-driven fiber scanner for an all-fiber non-linear microscopy imager. Background Art

[0002] Non-linear optical imaging is an imaging technique that generates image contrast based on non-linear optical effects occurring from the interaction between light and matter, and is widely used in the research of living organisms. Among them, Coherent anti-Stokes Raman Scattering (CARS) microscopy can obtain the molecular composition and distribution information of a sample to be measured based on the vibration or rotation characteristics of matter molecules without external labeling, and has good chemical specificity. In CARS microscopy, the integrated probe module is very important, and the scanning characteristics of the scanner in the probe part directly determine important indicators such as the imaging field of view, resolution, and frame rate of the system. Although the proximal scanning scheme with the scanning device located outside the endoscopic probe can reduce the difficulty of probe design and packaging, the core distance of the fiber bundle will limit the resolution of system imaging, and the pulse broadening during the transmission of femtosecond pulses needs to be compensated by a complex dispersion compensation module. The distal scanning scheme with the scanning device located inside the endoscopic probe is divided into two types: microelectromechanical system (MEMS) scanning and piezoelectric ceramic-driven fiber scanning. Most of the scanning schemes of MEMS scanning galvanometers need to achieve imaging through optical path folding, and it faces great challenges to reduce the lateral size of the system; in contrast, piezoelectric ceramic-driven fiber scanning has advantages such as a compact system, small size, and full fiberization. However, it is very difficult to fabricate high-quality micro piezoelectric ceramic tubular structures and electrodes. Summary of the Invention

[0003] The object of the present invention is to propose a tunable fiber scanner for an all-fiber non-linear microscopy imager. A micro scanning square tube assembled by four groups of four micro piezoelectric ceramic pieces is designed, and a compensated and corrected driving signal is applied to the micro scanning square tube by a piezoelectric ceramic driver, so that the scanning fiber performs resonant scanning along with the vibration of the micro piezoelectric ceramic pieces.

[0004] In order to achieve the above object of the invention, the present invention proposes the following technical solutions:

[0005] The tunable fiber optic scanner of a full-fiber nonlinear microscopy imager according to the present invention includes a fiber optic connector, a scanning optical fiber, a micro scanning square tube, a fiber optic ferrule, a screw regulator, a piezoelectric ceramic driver, a fixing collar and a packaging sleeve; wherein, the micro scanning square tube is assembled by four micro piezoelectric ceramic sheets, the fiber optic ferrule is tightly sleeved inside the micro scanning square tube, and a relative sliding is formed between the micro scanning square tube and the fiber optic ferrule. The scanning optical fiber is fixed in the micro scanning square tube through the fiber optic ferrule. The scanning optical fiber is located at the center of the micro scanning square tube. The fiber optic connector is connected to the scanning optical fiber. A screw regulator is fixed at the front end of the scanning optical fiber. The rear end of the scanning optical fiber passes through the inside of the fiber optic ferrule to form a fiber optic cantilever; the screw regulator controls the lateral movement of the scanning optical fiber to obtain a controllable fiber optic cantilever length; the piezoelectric ceramic driver is arranged outside the scanner and consists of a signal generator and a power amplifier: the signal generator is used to generate an alternating current signal to obtain the driving signal required for the scanning optical fiber, and the driving signal includes the scanning range and the scanning trajectory mode that the scanning optical fiber reaches; the power amplifier is used to amplify the driving signal output by the signal generator; the piezoelectric ceramic driver applies the compensated and corrected driving signal to the micro scanning square tube, so that the scanning optical fiber performs resonant scanning along with the vibration of the micro piezoelectric ceramic sheet, and the micro scanning square tube drives the fiber optic cantilever to perform resonant scanning; the fixing collar and the packaging sleeve are used for the fixation and packaging of the tunable fiber optic scanner.

[0006] A manufacturing method of a tunable fiber optic scanner of a full-fiber nonlinear microscopy imager includes the following steps:

[0007] Step 1: Prepare plastic clay, embed a rubber in the clay, expose the right-angled edges, dip a small amount of the mixed epoxy resin glue and evenly apply it on the side edges of two micro piezoelectric ceramic sheets, then increase the amount of glue and apply it on the edges where the micro piezoelectric ceramic sheets are joined, and fix for 24 hours to form a relatively stable L structure;

[0008] Step 2: Gently remove the L structure and place it in the groove in the middle of the glass mold, make one micro piezoelectric ceramic sheet of the L structure close to the glass sheet, and the other one is above the groove. Place the fiber optic ferrule under the L structure, close to the glass sheet, and stably support the L structure; evenly apply epoxy resin glue on the side edge of the third micro piezoelectric ceramic sheet and gently place it on the other side of the L structure, close to the fiber optic ferrule and the top micro piezoelectric ceramic sheet, and fix for 24 hours to form a U-shaped groove;

[0009] Step 3: After stripping the coating layer from one end of a section of scanning optical fiber, cut the optical fiber to ensure that the end face of the fiber cantilever is flat and smooth. Insert the scanning optical fiber into the fiber ferrule, leaving a specific cantilever length. Invert the U-shaped groove, place the fiber ferrule with the scanning optical fiber in the U-shaped groove, and dip a small amount of mixed epoxy resin glue to fix the fiber ferrule and the U-shaped groove. Take out the fourth micro piezoelectric ceramic sheet, cover it on the top of the U-shaped groove, evenly apply epoxy resin glue on the side edges on both sides, and fix it for 24 hours to form a stable micro scanning square tube assembled by micro piezoelectric ceramic sheets.

[0010] Step 4: Glue the cylindrical nut to the rear end of the micro scanning square tube with epoxy resin glue, pass the scanning optical fiber through it, and then add a matching screw rod to complete the construction of the screw regulator. Put the fixing collar 7 on the tail end of the micro scanning square tube and fix it firmly with epoxy resin glue, leaving a certain space to lead out the wire. Finally, fix the encapsulation sleeve and the fixing collar to each other. When the screw rod is tightened and the fiber cantilever length is the maximum, ensure that the 0 scale position on the outer wall of the encapsulation sleeve coincides with the scale position of the screw regulator to form a stable four-piece assembled tunable fiber scanner.

[0011] Compared with the prior art, the present invention has the following advantages:

[0012] (1) The four micro piezoelectric ceramic sheets are fabricated through a die-assisted preparation process flow, without the need to use independent tubular structure vibration devices with relatively high processing complexity such as piezoelectric ceramic tubes. Mass production is easy, the cost is low, and the control degree of size and electronic parameters is high.

[0013] (2) The four-piece assembled structure enables the convenient fixation of fiber ferrules with different sizes inside the scanner, ensuring that the outer diameter of the fiber ferrule and the width of the micro piezoelectric ceramic sheet are mutually adapted, and the use of the fiber ferrule significantly enhances the central symmetry and stability of the system.

[0014] (3) In specific applications, the size of the micro piezoelectric ceramic sheet can be adjusted and different types of optical fibers can be selected to fabricate the scanner, which is of great significance for practical applications.

[0015] (4) According to the requirements of different imaging fields of view, scanning ranges, imaging frame rates, and scanning speeds, the vibration amplitude of the fiber cantilever end can be tuned by applying different compensation and correction voltage signals through the piezoelectric ceramic driver, or the resonant frequency of the fiber cantilever can be tuned by changing the fiber cantilever length through the screw regulator, improving the flexibility of the scanner application.

[0016] (5) The overall size of this scanner device is small and the performance is excellent, promising to open up a new paradigm for optical microscopy applications in life science research and clinical medical applications. Description of the Drawings

[0017] Figure 1Schematic diagram of the tunable fiber optic scanner structure of a full-fiber nonlinear microscopy imager of the present invention, (1a) Structure of the tunable fiber optic scanner of the full-fiber nonlinear microscopy imager, (1b) Local structure A, (1c) Local structure B, (1d) Local structure C;

[0018] Figure 2 Schematic diagram of the scale magnification of the scanner and the screw regulator;

[0019] Figure 3 Schematic diagram of the production of the "L" structure in the scanner manufacturing process;

[0020] Figure 4 Schematic diagram of the side of the scanner manufacturing mold;

[0021] Figure 5 Schematic diagram of the overall scanner manufacturing mold;

[0022] Figure 6 Schematic diagram of the scanning of the fiber optic scanner;

[0023] Figure 7 Schematic diagram of the relationship between the drive signal and the scanning range and the frequency sweep near the resonance frequency point;

[0024] Figure 8 Schematic diagram of the mode for simulating the surface displacement amplitude of the bare scanner, (8a) Mode 1 simulation, where the resonance characteristic frequency = 311.27 Hz, surface displacement amplitude (unit: mm), (8b) Mode 2 simulation, where the resonance characteristic frequency = 353.07 Hz, (8c) Mode 3 simulation, where the resonance characteristic frequency = 1958.6 Hz, (8d) Mode 1 simulation, where the resonance characteristic frequency = 2208.8 Hz;

[0025] Reference numerals:

[0026] 1. Fiber optic connector, 2. Scanning optical fiber, 3. Microscopic scanning square tube, 4. Fiber optic ferrule, 21. Front end of the scanning optical fiber, 22. Fiber optic cantilever, 31 - 34. Micro piezoelectric ceramic sheets, 35. Conducting wire, 5. Screw regulator, 6. Piezoelectric ceramic driver, 7. Fixed collar, 8. Encapsulation sleeve, 9. Epoxy resin glue, 10. Plastic clay, 11. Rubber, 12. Glass mold, 121 - 123. Glass sheets, 13. Nonlinear microscopy excitation source, 14. Hole, 15. Nut, 16. Screw, 17. Handle. Detailed implementation manners

[0027] The technical solution of the present invention will be further described below in conjunction with the drawings and embodiments.

[0028] As Figure 1As shown, the tunable fiber scanner of the all-fiber nonlinear microscopy imager of the present invention includes a scanning component and a driving component;

[0029] A spiral regulator is fixed at the front end of the scanning fiber. The spiral regulator controls the lateral movement of the scanning fiber to generate a fiber cantilever with a controllable length;

[0030] The scanning component includes a micro scanning square tube, which is assembled by four micro piezoelectric ceramic sheets. The fiber ferrule is tightly sleeved inside the micro scanning square tube. The rear end of the scanning fiber passes through the inside of the fiber ferrule and is fixed at the center position of the micro scanning square tube through the fiber ferrule. The relative sliding between the scanning fiber and the fiber ferrule forms a fiber cantilever. The scanning fiber moves laterally under the control of the spiral regulator to obtain an adjustable fiber cantilever length;

[0031] The driving component includes a piezoelectric ceramic driver arranged outside the scanner. The piezoelectric ceramic driver includes a signal generator and a power amplifier. The signal generator is used to generate a driving signal, and the power amplifier is used to amplify the driving signal output by the signal generator. The piezoelectric ceramic driver applies the amplified driving signal to the micro scanning square tube. The micro scanning square tube receives the amplified driving signal, drives the scanning fiber to scan, and drives the fiber cantilever to perform resonant scanning.

[0032] The micro scanning square tube 3, which is the core device of the fiber optic scanner, is an assembled structure composed of four micro piezoelectric ceramic sheets 31-34. The fiber optic ferrule 4 is tightly sleeved inside the micro scanning square tube 3, and the scanning optical fiber 2 is fixed inside the micro scanning square tube 3 through the fiber optic ferrule 4 to ensure that the scanning optical fiber 2 is located at the center of the micro scanning square tube, so as to enhance the central symmetry and stability of the system and improve the scanning quality. The fiber optic connector 1 is connected to the scanning optical fiber 2. A spiral regulator 5 is fixed at the front end of the scanning optical fiber 2, and the rear end of the scanning optical fiber 2 passes through the inside of the fiber optic ferrule 4 to form an optical fiber cantilever 22. A relatively fixed structure is formed between the scanning optical fiber 2 and the spiral regulator 5, and a relatively sliding structure is formed between the scanning optical fiber 2 and the fiber optic ferrule 4. The spiral regulator 5 controls the lateral movement of the scanning optical fiber 2 by screwing in and out through the internal thread to obtain a controllable optical fiber cantilever length. The piezoelectric ceramic driver 6 is arranged outside the scanner and consists of a signal generator and a power amplifier. The signal generator is used to generate an alternating current signal, and the driving signal required for the scanning optical fiber is obtained by regulating the amplitude and phase parameters of the alternating current signal. The driving signal includes the scanning range and the scanning trajectory mode that the scanning optical fiber reaches. The power amplifier is used to amplify the low-power driving signal output by the signal generator. The micro scanning square tube 3 receives the amplified driving signal and drives the scanning optical fiber 2 to scan according to the required scanning range and scanning trajectory mode. Both x and y are input channels of two axes. That is, the piezoelectric ceramic driver 6 applies a driving signal to the micro scanning square tube 3, so that the scanning optical fiber scans with the vibration of the micro piezoelectric ceramic sheet, and thus the micro scanning square tube 3 assembled by the micro piezoelectric ceramic sheets drives the end of the optical fiber cantilever 22 to perform resonant scanning. The fixing collar 7 and the encapsulation sleeve 8 are used for the fixing and encapsulation of the scanner.

[0033] Specifically, the suspended end of the fiber optic connector is connected to the non-linear microscopy excitation source, which has low insertion loss and high repeatability and can efficiently complete the optical path connection. The fiber optic connector has low insertion loss and high repeatability and can efficiently complete the optical path connection.

[0034] Specifically, the micro scanning square tube is made by a die-assisted assembly process flow from four micro piezoelectric ceramic sheets 31-34. The length range of the micro piezoelectric ceramic sheet is 17-26 mm, the width is 1.5 mm, and the thickness range is 0.3-0.7 mm. During the manufacturing process, the polarization directions of the two relatively micro piezoelectric ceramic sheets 31, 33 and 32, 34 need to be kept consistent, and the same alternating current signal is provided by the piezoelectric ceramic driver 5 to the outer walls of the two relatively micro ceramic sheets, and they have the same driving voltage waveform signal. The inner walls of the micro ceramic sheets are connected as a whole electrode through copper powder conductive adhesive and grounded. The copper powder conductive adhesive covers the inner wall with a length of 2-3 mm. The actual resonance frequency of the optical fiber cantilever 22 is found through sweep frequency testing, and the scanning work of the micro piezoelectric ceramic square tube is carried out at the resonance frequency.

[0035] Specifically, if the structure of the micro piezoelectric ceramic sheet shows asymmetry, the stable operation of the scanning optical fiber is achieved by compensating and correcting the driving signal.

[0036] Specifically, the scanning optical fiber 2 is used for optical path transmission and resonant scanning. The types of optical fibers used in the tunable optical fiber scanner of the present invention include single-mode optical fibers, multi-mode optical fibers, multi-core optical fibers, microstructure optical fibers, etc.

[0037] Specifically, the length of the fiber cantilever 22 is tuned by the screw regulator 5, and the tuning range is 5 to 17 mm, which is determined by the required scanning frequency design.

[0038] Specifically, the outer diameter of the fiber ferrule 4 is the same as the width of the micro piezoelectric ceramic sheet, and it forms a tight fit with the inner diameter of the micro scanning square tube 3 assembled with the micro piezoelectric ceramic sheet during assembly.

[0039] The screw regulator 5 completes the tuning of the fiber cantilever length and the resonant frequency based on the principle of screw amplification. The nut 15 at the rear end and the micro scanning square tube are adhered by epoxy resin glue 9. A rectangular hole 14 is provided on the encapsulation sleeve for leading out the wire 35, and the scanning optical fiber 2 slides freely in the hole 4. The screw 16 at the front end is fixed to the scanning optical fiber 2. By rotating the handle 17 at the tail of the scanner, the screw 16 can rotate on the nut 15, driving the scanning optical fiber to move along the central axis direction of the scanner, realizing the change of the fiber cantilever length and the tuning of the resonant frequency. When the front screw rotates one week on the nut, the screw advances or retreats a distance of one thread, that is, 1 mm, which is also the distance between every two circular ring scale lines on the screw. There are 100 equally divided small scales for the movable scale of the screw for each rotation. Therefore, for each rotation of a small division, the fiber cantilever advances or retreats 0.01 mm. According to the number of circular ring scale lines left outside the encapsulation sleeve 8 by the screw regulator 5, the millimeter order of magnitude of the fiber cantilever length can be determined; according to the comparison between the linear scale of the screw regulator 5 and the external scale lines of the encapsulation sleeve 8, the reading can be accurate to 0.01 mm. Since one more digit can be estimated, the fiber cantilever length can be read to the thousandth place of a millimeter in total.

[0040] The total length of the fixed collar 7 is 4 mm. The outer wall is cylindrical, and there is a square aperture inside, which is matched with the size of the micro piezoelectric ceramic sheet and is tightly fixed to the encapsulation sleeve 8 and the micro scanning square tube 3. The encapsulation sleeve 8 is a stainless steel tube, which is used to protect the micro scanning square tube 3 and the screw regulator 5. The total length is 40 mm, the wall thickness is 0.5 mm, the inner diameter is matched with the size of the fixed collar, and there is a 5-mm long opening for leading out the wire at the 10 - 15 mm position in the middle; there is a 0 scale line engraved at one end of the outer wall close to the screw regulator 5 for reading in cooperation with the scale on the screw regulator. When the fiber cantilever length is an integer millimeter length, the scale line on the encapsulation sleeve is aligned with the 0 scale line on the screw regulator.

[0041] When facing different applications, micro piezoelectric ceramic chips of different sizes can be selected to fabricate the micro scanning square tube or the driving signal of the driver can be changed to meet the requirements of different imaging fields of view. The resonant frequency can also be adjusted by controlling the length of the fiber cantilever through a screw regulator to achieve the control of different scanning speeds and imaging frame rates.

[0042] Schematic diagram of a four-piece assembled tunable fiber scanner for a non-linear microscope according to the present invention. The scanner at least includes a fiber optic connector (1), a scanning optical fiber (2), a micro scanning square tube (3) assembled by micro piezoelectric ceramic chips, an optical fiber ferrule (4), a screw regulator (5), a piezoelectric ceramic driver (6), a fixing collar (7) and a packaging sleeve (8).

[0043] A method for fabricating a tunable fiber scanner of an all-fiber non-linear microscope according to the present invention, the method comprising the following steps:

[0044] Step 1: First, prepare the plastic clay 10, embed the rubber 11 into the clay, and expose the right-angled edges for conveniently placing the micro piezoelectric ceramic chips. Subsequently, mix the epoxy resin glue 9 and dip a steel needle into a small amount of the mixed glue and evenly apply it on the side edges of the two micro piezoelectric ceramic chips; gently place the micro piezoelectric ceramic chips with a small amount of epoxy resin glue 9 on one end of the right-angled edge of the rubber 11. After ensuring stability, use a steel needle to increase the amount of glue applied on the edges where the micro piezoelectric ceramic chips are joined. After fixing for 24 hours, a relatively stable L structure can be formed;

[0045] Step 2: Gently remove the L structure and place it in the groove in the middle of the glass mold, making one micro piezoelectric ceramic chip of the L structure closely adhere to the glass sheet 122, and the other one is above the groove; it should be noted that the groove in the middle of the glass mold is specifically designed, and its length is equal to the length of the piezoelectric ceramic chip, which can stably place the micro piezoelectric ceramic chip therein. Place the optical fiber ferrule 4 under the L structure, closely adhere to the glass sheet 123, and stably support the L structure. Use a steel needle to evenly apply epoxy resin glue 9 on the side edges of the third micro piezoelectric ceramic chip and gently place it on the other side of the L structure, closely adhering to the optical fiber ferrule and the top micro piezoelectric ceramic chip, and fix for 24 hours to form a U-shaped groove;

[0046] Step 3: After stripping the coating layer from one end of a section of scanning optical fiber 2, use an optical fiber cutter to cut it to ensure that the end face of the optical fiber cantilever end is flat and smooth. Then insert the scanning optical fiber 2 into the optical fiber ferrule 4, leaving a specific cantilever length. Invert the U-shaped groove so that the side without the micro ceramic sheet faces upward and place it in the glass mold 10. Place the optical fiber ferrule 4 with the scanning optical fiber 2 inserted into the U-shaped groove, and use a steel needle to dip a small amount of mixed epoxy resin glue 9 to fix the optical fiber ferrule 4 and the U-shaped groove. Finally, take out the fourth micro piezoelectric ceramic sheet and cover it on the top of the U-shaped groove, evenly apply epoxy resin glue 9 on the side edges on both sides, and fix it for 24 hours to form a stable micro scanning square tube 3 assembled by micro piezoelectric ceramic sheets;

[0047] Step 4: Glue a cylindrical nut to the rear end of the micro scanning square tube (3) with epoxy resin glue 9, pass the scanning optical fiber 2 through it, and then add a matching screw rod to complete the construction of the screw regulator 5. Slip the fixing collar 7 onto the tail end of the micro scanning square tube 3 and fix it firmly with epoxy resin glue 9, ensuring that there is a certain space to lead out the wire. Finally, fix the encapsulation sleeve 8 and the fixing collar (7) to each other. When the screw rod is tightened and the optical fiber cantilever length is at its maximum, ensure that the 0 scale position on the outer wall of the encapsulation sleeve 8 coincides with the 0 scale position of the screw regulator 5 to form a stable four-piece assembled tunable fiber scanner.

[0048] The four-piece combined piezoelectric-driven fiber scanner described above is fabricated using a specific process flow. The mass production of micro piezoelectric ceramic sheets is easy, and the control of their size and electronic parameters is high. Therefore, compared with assembling a vibration device with an independent tubular structure directly and an optical fiber, using 4 micro piezoelectric ceramic sheets for assembly has a lower cost and higher flexibility. When facing different applications, different-sized micro piezoelectric ceramic sheets can be selected at any time to fabricate the micro scanning tube or the fiber cantilever length and resonance frequency can be changed through the screw regulator to meet different imaging performance requirements. The assembled structure also makes it very convenient to fix optical fiber ferrules of different sizes inside the scanner, thus significantly improving the central symmetry and stability of the system, which is of great significance for the practical application of nonlinear microscopy imaging technology.

[0049] The above specific embodiments do not limit the technical solution of the present invention. For those skilled in the art, improvements and changes can be made based on the above-described invention content. Any modifications, equivalent replacements, improvements, or changes made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for manufacturing a tunable optical fiber scanner for an all-optical nonlinear microscopic imager, characterized in that: The following steps are involved: Step 1: Prepare plastic clay, embed the rubber into the clay, expose the right-angled edges, dip a small amount of mixed epoxy resin glue and evenly apply it on the side edges of the two micro piezoelectric ceramic sheets, then increase the amount of glue and apply it on the edges where the micro piezoelectric ceramic sheets meet, fix it for 24 hours to form a more stable L structure; Step 2: Gently remove the L structure and place it in the groove in the middle of the glass mold, so that one micro piezoelectric ceramic sheet of the L structure is close to the glass sheet and the other is above the groove. Place the optical fiber ferrule under the L structure, close to the glass sheet, and stably support the L structure; evenly apply epoxy resin glue on the side edges of the third micro piezoelectric ceramic sheet and gently place it on the other side of the L structure, close to the optical fiber ferrule and the top micro piezoelectric ceramic sheet, and fix it for 24 hours to form a U-shaped groove; Step 3: After stripping the coating layer from one end of a scanning optical fiber, cut the optical fiber to ensure that the end face of the optical fiber cantilever end is flat and smooth, insert the scanning optical fiber into the optical fiber ferrule, and leave a specific cantilever length; invert the U-shaped groove, place the optical fiber ferrule with the scanning optical fiber in the U-shaped groove, and apply a small amount of mixed epoxy resin glue to fix the optical fiber ferrule and the U-shaped groove; take out the fourth micro piezoelectric ceramic sheet and cover it on the top of the U-shaped groove, evenly apply epoxy resin glue on the side edges on both sides, and fix it for 24 hours to form a stable micro scanning square tube assembled by micro piezoelectric ceramic sheets; Step 4: Use epoxy resin glue to glue the cylindrical nut to the rear end of the micro scanning square tube, pass the scanning optical fiber through it, and then add a screw to complete the construction of the spiral adjuster; put the fixed ring 7 on the rear end of the micro scanning square tube, fix it firmly with epoxy resin glue, and leave a certain space to lead out the wire; finally, fix the packaging sleeve and the fixed ring to each other, and when the screw is tightened and the fiber cantilever length is maximum, ensure that the 0 mark position on the outer wall of the packaging sleeve coincides with the mark position of the spiral adjuster to form a stable four-piece assembled tunable fiber scanner.

2. The method for manufacturing a tunable optical fiber scanner for an all-optical nonlinear microscopic imager according to claim 1, characterized in that: The tunable optical fiber scanner of the all-fiber nonlinear microscopic imager comprises a scanning component and a driving component. The scanning component comprises a micro scanning square tube, which is assembled from four micro piezoelectric ceramic sheets. The micro scanning square tube is tightly sleeved with an optical fiber ferrule. A spiral adjuster is fixed to the front end of the scanning optical fiber, and the rear end passes through the inside of the optical fiber ferrule and is fixed to the center of the micro scanning square tube through the optical fiber ferrule. The scanning optical fiber slides relatively with the optical fiber ferrule to form an optical fiber cantilever. The driving component includes a piezoelectric ceramic driver arranged outside the scanner, the piezoelectric ceramic driver includes a signal generator and a power amplifier, the signal generator is used to generate a driving signal, the power amplifier is used to amplify the driving signal output by the signal generator, the piezoelectric ceramic driver applies the amplified driving signal to the micro scanning square tube, the micro scanning square tube receives the amplified driving signal, drives the scanning optical fiber to scan, and drives the optical fiber cantilever to perform resonant scanning.

3. The method for manufacturing a tunable optical fiber scanner for an all-optical nonlinear microscopic imager according to claim 1, characterized in that: When the micro piezoelectric ceramic sheet structure is asymmetric, optical fiber scanning is achieved by compensating and correcting the driving signal.

4. The method for manufacturing a tunable optical fiber scanner for an all-optical nonlinear microscopic imager according to claim 1, characterized in that: The scanning optical fiber moves laterally under the control of a spiral adjuster to obtain an adjustable optical fiber cantilever length.

5. The method for manufacturing a tunable optical fiber scanner for an all-optical nonlinear microscopic imager according to claim 1, characterized in that: The micro-scanning square tube has input channels x and y in two axial directions.

6. The method for manufacturing a tunable optical fiber scanner for an all-optical nonlinear microscopic imager according to claim 1, characterized in that: The scanning optical fiber is connected to an optical fiber connector, and a suspended end of the optical fiber connector is connected to a nonlinear microscopic imaging excitation source.

7. The method for manufacturing a tunable optical fiber scanner for an all-optical nonlinear microscopic imager according to claim 1, characterized in that: The polarization directions of the two opposite micro piezoelectric ceramic sheets are consistent, and the outer walls of the two opposite micro piezoelectric ceramic sheets are provided with the same AC signal by the piezoelectric ceramic driver and have the same driving signal.

8. The method for manufacturing a tunable optical fiber scanner for an all-optical nonlinear microscopic imager according to claim 1, characterized in that: The inner wall of the micro piezoelectric ceramic sheet is connected to form an integral electrode and grounded via copper powder conductive glue, and the inner wall is covered by the copper powder conductive glue for a length of 2 to 3 mm.

9. The method for manufacturing a tunable optical fiber scanner for an all-optical nonlinear microscopic imager according to claim 1, characterized in that: Specifically, the length of the optical fiber cantilever is adjusted by a spiral adjuster, and the tuning range is 5 to 17 mm.

10. The method for manufacturing a tunable optical fiber scanner for an all-optical nonlinear microscopic imager according to claim 1, characterized in that: Specifically, the outer diameter of the optical fiber ferrule is consistent with the width of the micro piezoelectric ceramic sheet, and forms a tight fit with the inner diameter of the micro scanning square tube assembled with the micro piezoelectric ceramic sheet during assembly.

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