Tunable optical fiber scanner of all-optical-fiber nonlinear microscopic imager and manufacturing method

Abstract

The invention discloses a tunable optical fiber scanner of an all-fiber nonlinear microscopic imager, which comprises a scanning optical fiber, a scanning assembly and a driving assembly, and is characterized in that a spiral regulator is fixed at the front end of the scanning optical fiber; the scanning assembly comprises a miniature scanning square tube, a scanning optical fiber is fixed at the central position of the miniature scanning square tube, the scanning optical fiber and an optical fiber insertion core relatively slide to form an optical fiber cantilever, and the scanning optical fiber transversely moves under the control of a spiral adjuster to obtain the adjustable length of the optical fiber cantilever; the driving assembly comprises a piezoelectric ceramic driver arranged outside the scanner, the piezoelectric ceramic driver applies an amplified driving signal to the micro scanning square tube, and 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 resonance scanning. Compared with the prior art, resonance scanning capable of being precisely controlled is achieved by combining the micro scanning square tube and the scanning optical fiber resonance scanning, and the device is used for optical microscopic imaging equipment.

Description

Technical Field

[0001] The invention relates to the field of nonlinear optical imaging and optical fiber scanning, and in particular to a four-piece assembled tunable piezoelectric driven optical fiber scanner for an all-optical nonlinear microscopic imager. Background Art

[0002] Nonlinear optical imaging is an imaging technology that produces image contrast based on the nonlinear optical effect of the interaction between light and matter. It is widely used in the study of living organisms. Among them, coherent anti-Stokes Raman scattering (CARS) microscopy can obtain the molecular composition and distribution information of the sample to be tested based on the vibration or rotation characteristics of the material molecules without external labeling, and has good chemical specificity. In CARS microscopy, the integrated probe module is very important. 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 in which the scanning device is located outside the endoscope probe can reduce the difficulty of probe design and packaging, the core distance of the fiber bundle will limit the resolution of the system imaging, and the pulse broadening during femtosecond pulse transmission needs to be compensated by a complex dispersion compensation module. The distal scanning scheme in which the scanning device is located inside the endoscope probe is divided into two types: microelectromechanical system (MEMS) scanning and piezoelectric ceramic driven fiber scanning. Most MEMS scanning galvanometer scanning solutions require the folding of the optical path to achieve imaging, which poses a huge challenge to reducing the lateral size of the system; in contrast, piezoelectric ceramic-driven fiber scanning has the advantages of compact system, small size, and full fiberization. However, it is very difficult to produce high-quality micro-piezoelectric ceramic tubular structures and electrodes. Summary of the invention

[0003] The purpose of the present invention is to propose a tunable optical fiber scanner for an all-fiber nonlinear microscopic imager, which utilizes a micro scanning square tube assembled from four groups of four micro piezoelectric ceramic sheets designed, and a piezoelectric ceramic driver applies a compensated and corrected driving signal to the micro scanning square tube, thereby realizing resonant scanning of the scanning optical fiber following the vibration of the micro piezoelectric ceramic sheets.

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

[0005] The invention discloses a tunable optical fiber scanner for an all-optical nonlinear microscopic imager, comprising an optical fiber connector, a scanning optical fiber, a micro-scanning square tube, an optical fiber insert, a spiral regulator, a piezoelectric ceramic driver, a fixing ring and a packaging sleeve; wherein the micro-scanning square tube is assembled from four micro-piezoelectric ceramic sheets, the optical fiber insert is tightly sleeved inside the micro-scanning square tube, and a relative sliding is formed between the optical fiber insert and the optical fiber insert, the scanning optical fiber is fixed in the micro-scanning square tube through the optical fiber insert, the scanning optical fiber is located at the center of the micro-scanning square tube, the optical fiber connector is connected to the scanning optical fiber, a spiral regulator is fixed at the front end of the scanning optical fiber, and the rear end of the scanning optical fiber passes through the inside of the optical fiber insert to form an optical fiber cantilever; the spiral regulator controls the scanning optical fiber Generate lateral movement to obtain a controllable optical fiber 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 AC signal to obtain a driving signal required for scanning the optical fiber, and the driving signal includes a scanning range and a scanning trajectory mode achieved by driving the scanning optical fiber; the power amplifier is used to amplify the driving signal output by the signal generator; the piezoelectric ceramic driver applies a compensated and corrected driving signal to the micro scanning square tube, so that the scanning optical fiber resonates and scans with the vibration of the micro piezoelectric ceramic piece, and the micro scanning square tube drives the optical fiber cantilever to resonate and scan; the fixed ring and the packaging sleeve are used for fixing and packaging the tunable optical fiber scanner.

[0006] A method for manufacturing a tunable optical fiber scanner for an all-optical nonlinear microscopic imager comprises the following steps:

[0007] 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;

[0008] 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;

[0009] 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;

[0010] 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.

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

[0012] (1) Four micro piezoelectric ceramic sheets are made through a mold-assisted preparation process, without the need to use independent tubular structure vibration devices such as piezoelectric ceramic tubes, which have relatively high processing complexity; batch production is easy, the cost is low, and the size and electronic parameters are highly controlled;

[0013] (2) The four-piece assembly structure makes it easy to fix fiber optic ferrules of different sizes inside the scanner, ensuring that the outer diameter of the fiber optic ferrule and the width of the micro piezoelectric ceramic piece are compatible with each other. The use of the fiber optic 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 optical fiber types can be selected to make scanners, 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 correction voltage signals through the piezoelectric ceramic driver, or the resonant frequency of the fiber cantilever can be tuned by changing the length of the fiber cantilever through the spiral regulator, thereby improving the flexibility of the scanner application;

[0016] (5) The scanner device has a compact overall size and excellent performance, and is expected to open up a new paradigm for optical microscopy applications in life science research and clinical medicine. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1Schematic diagram of a tunable fiber scanner structure of an all-fiber nonlinear microscopic imager of the present invention, (1a) tunable fiber scanner structure of an all-fiber nonlinear microscopic imager, (1b) local A structure, (1c) local B structure, (1d) local C structure;

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

[0019] Figure 3 A schematic diagram of the "L" structure of the scanner process production flow;

[0020] Figure 4 Schematic diagram of the side view of the mold for the scanner process;

[0021] Figure 5 Make an overall schematic diagram of the mold for the scanner process;

[0022] Figure 6 It is a schematic diagram of scanning by a fiber optic scanner;

[0023] Figure 7 The relationship between the driving signal and the scanning range and the schematic diagram of the frequency scanning near the resonant frequency point;

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

[0025] Reference numerals:

[0026] 1. Fiber optic connector, 2. Scanning optical fiber, 3. Miniature scanning square tube, 4. Fiber optic ferrule, 21. Scanning optical fiber front end, 22. Fiber optic cantilever, 31-34. Miniature piezoelectric ceramic sheet, 35. Wire, 5. Screw adjuster, 6. Piezoelectric ceramic driver, 7. Fixed ring, 8. Packaging sleeve, 9. Epoxy resin glue, 10. Plastic clay, 11. Rubber, 12. Glass mold, 121-123. Glass sheet, 13. Nonlinear microscopic imaging excitation source, 14. Hole, 15. Nut, 16. Screw, 17. Handle. DETAILED DESCRIPTION

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

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

[0029] A spiral adjuster is fixed at the front end of the scanning optical fiber, and the spiral adjuster controls the scanning optical fiber to produce lateral movement, thereby generating a fiber cantilever with controllable length;

[0030] The scanning component includes 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. The rear end of the scanning optical fiber passes through the optical fiber ferrule and is fixed at the center of the micro scanning square tube through the optical fiber ferrule. The scanning optical fiber slides relative to the optical fiber ferrule to form an optical fiber cantilever. The scanning optical fiber moves laterally under the control of a spiral regulator to obtain an adjustable optical fiber cantilever length.

[0031] The driving component includes a piezoelectric ceramic driver arranged outside the scanner, and 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, and 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.

[0032] The micro scanning square tube 3, which is the core component of the optical fiber scanner, is an assembled structure composed of four micro piezoelectric ceramic sheets 31 to 34. The optical fiber ferrule 4 is tightly sleeved inside the micro scanning square tube 3, and the scanning optical fiber 2 is fixed in the micro scanning square tube 3 through the optical fiber ferrule 4, ensuring that the scanning optical fiber 2 is located at the center of the micro scanning square tube to enhance the central symmetry and stability of the system and improve the scanning quality. The optical fiber connector 1 is connected to the scanning optical fiber 2. A spiral adjuster 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 optical fiber ferrule 4 to form an optical fiber cantilever 22. A relatively fixed structure is formed between the scanning optical fiber 2 and the spiral adjuster 5, and a relatively sliding structure is formed between the scanning optical fiber 2 and the optical fiber ferrule 4. The spiral adjuster 5 controls the scanning optical fiber 2 to produce lateral movement by screwing in and out of 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 AC signal, and the driving signal required for the scanning optical fiber is obtained by adjusting the amplitude and phase parameters of the AC signal. The driving signal includes the scanning range and scanning trajectory mode achieved by driving the scanning optical fiber. 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. x and y are both two axial input channels. That is, the piezoelectric ceramic driver 6 applies a driving signal to the micro scanning square tube 3, so that the scanning optical fiber is scanned with the vibration of the micro piezoelectric ceramic sheet, so that the micro scanning square tube 3 assembled by the micro piezoelectric ceramic sheet drives the end of the optical fiber cantilever 22 to resonate and scan. The fixing ring 7 and the packaging sleeve 8 are used for fixing and packaging the scanner.

[0033] Specifically, the suspended end of the optical fiber connector is connected to a nonlinear microscopic imaging excitation source, has low insertion loss and high repeatability, and can efficiently complete the optical path connection. The optical fiber 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 of four micro piezoelectric ceramic sheets 31 to 34 through a mold-assisted assembly process. The length range of the micro piezoelectric ceramic sheets is 17 to 26 mm, the width is 1.5 mm, and the thickness range is 0.3 to 0.7 mm. During the manufacturing process, the polarization directions of the two relative micro piezoelectric ceramic sheets 31, 33 and 32, 34 must be kept consistent, and the outer walls of the two relative micro ceramic sheets are provided with the same AC signal by the piezoelectric ceramic driver 5, and have the same driving voltage waveform signal. The inner wall of the micro ceramic sheet is connected to an integral electrode and grounded through copper powder conductive glue, and the inner wall length covered by the copper powder conductive glue is 2 to 3 mm. The actual resonant frequency of the optical fiber cantilever 22 is found through a frequency sweep test, and the scanning of the micro piezoelectric ceramic square tube is performed at the resonant frequency.

[0035] Specifically, if the micro piezoelectric ceramic structure is asymmetric, 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 resonance scanning. The optical fiber types used in the tunable optical fiber scanner of the present invention include single-mode optical fiber, multi-mode optical fiber, multi-core optical fiber, microstructure optical fiber, etc.

[0037] Specifically, the length of the optical fiber cantilever 22 is adjusted by the spiral adjuster 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 optical fiber ferrule 4 is consistent with the width of the micro piezoelectric ceramic sheet, and during assembly, it is closely fitted with the inner diameter of the micro scanning square tube 3 assembled from the micro piezoelectric ceramic sheet.

[0039] The spiral regulator 5 completes the tuning of the fiber cantilever length and the resonant frequency based on the principle of spiral amplification. The nut 15 at the rear end and the micro scanning square tube are bonded by epoxy resin glue 9. A rectangular hole 14 is set on the packaging sleeve for leading out the wire 35. 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 of the scanner, so as to change the fiber cantilever length and tune the resonant frequency. When the front screw rotates one circle on the nut, the screw moves forward or backward by the distance of one thread, that is, 1 mm, which is the distance between every two circular ring lines on the screw. The movable scale of the screw has 100 equally divided small scales for each rotation of the screw. Therefore, for each small scale rotation, the fiber cantilever moves forward or backward by 0.01 mm. The millimeter level of the optical fiber cantilever length can be determined based on the number of circular scale lines left by the spiral adjuster 5 on the outside of the packaging sleeve 8; the reading can be accurate to 0.01 mm by comparing the linear scale of the spiral adjuster 5 with the external scale lines of the packaging sleeve 8. Since one more digit can be estimated, the optical fiber cantilever length can be read to thousandths of a millimeter in total.

[0040] The fixed collar 7 has a total length of 4 mm, a cylindrical outer wall, and a square aperture inside, which matches the size of the micro piezoelectric ceramic piece and is tightly fixed to the packaging sleeve 8 and the micro scanning square tube 3. The packaging sleeve 8 is a stainless steel tube, which is used to protect the micro scanning square tube 3 and the spiral adjuster 5. It has a total length of 40 mm, a wall thickness of 0.5 mm, an inner diameter that matches the size of the fixed collar, and a 5 mm long opening is left at 10 to 15 mm in the middle to lead out the wire; the outer wall is engraved with a 0 mark at one end close to the spiral adjuster 5, which is used to match the scale on the spiral adjuster for reading. When the length of the optical fiber cantilever is an integer millimeter, the mark on the packaging sleeve is aligned with the 0 mark on the spiral adjuster.

[0041] When facing different applications, you can choose micro piezoelectric ceramics of different sizes to make micro scanning square tubes or change the driving signal of the driver to meet different imaging field requirements. You can also adjust the resonant frequency by controlling the length of the optical fiber cantilever through a spiral regulator to achieve control of different scanning speeds and imaging frame rates.

[0042] A schematic diagram of a four-piece assembled tunable optical fiber scanner for a nonlinear microscopic imager of the present invention. The scanner comprises at least an optical fiber connector (1), a scanning optical fiber (2), a micro scanning square tube (3) assembled from micro piezoelectric ceramic sheets, an optical fiber insert (4), a spiral adjuster (5), a piezoelectric ceramic driver (6), a fixing ring (7) and a packaging sleeve (8).

[0043] The method for manufacturing a tunable optical fiber scanner of an all-optical nonlinear microscopic imager of the present invention comprises the following steps:

[0044] Step 1: First prepare the plastic clay 10, and embed the eraser 11 into the clay, exposing the right-angled edges to facilitate the placement of the micro piezoelectric ceramic sheet. Then, mix the epoxy resin glue 9 and use a steel needle to dip a small amount of the mixed glue and evenly apply it on the side edges of the two micro piezoelectric ceramic sheets; gently place the micro piezoelectric ceramic sheet with a small amount of epoxy resin glue 9 on the side edge on one end of the right-angled edge of the eraser 11, and after ensuring stability, use a steel needle to increase the amount of glue and apply it to the edges where the micro piezoelectric ceramic sheets meet. 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, so that one micro piezoelectric ceramic piece of the L structure is close to the glass piece 122, and the other piece is above the groove; it is worth noting that the groove in the middle of the glass mold is specially designed, and its length is equal to the length of the piezoelectric ceramic piece, so that the micro piezoelectric ceramic piece can be stably placed therein. Place the optical fiber ferrule 4 under the L structure, close to the glass piece 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 piece and gently place it on the other side of the L structure, close to the optical fiber ferrule and the top micro piezoelectric ceramic piece, and fix it for 24 hours to form a U-shaped groove;

[0046] Step 3: After stripping off the coating on one end of a section of scanning optical fiber 2, cut it with a fiber optic cutter to ensure that the end face of the optical fiber cantilever end is flat and smooth, and then insert the scanning optical fiber 2 into the optical fiber ferrule 4, leaving a specific cantilever length. Invert the U-shaped groove, and place the side of the U-shaped groove without the micro-ceramic sheet upward in the glass mold 10, and place the optical fiber ferrule 4 with the scanning optical fiber 2 in 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 from micro piezoelectric ceramic sheets;

[0047] Step 4: Use epoxy resin glue 9 to glue the rear end of the micro scanning square tube (3) to the cylindrical nut, pass the scanning optical fiber 2 through it, and then add a screw to complete the construction of the spiral adjuster 5. Put the fixing ring 7 on the rear end of the micro scanning square tube 3 and fix it firmly with epoxy resin glue 9, ensuring that a certain space is left for leading out the wire. Finally, fix the packaging sleeve 8 and the fixing ring (7) to each other. When the screw is tightened and the fiber cantilever length is the maximum, ensure that the outer wall 0 mark position of the packaging sleeve 8 and the spiral adjuster 50 mark position coincide, forming a stable four-piece assembled tunable optical fiber scanner.

[0048] In summary, the four-piece piezoelectric-driven fiber scanner is manufactured using a specific process flow. Micro piezoelectric ceramic sheets are easy to mass-produce, and the size and electronic parameters are highly controlled. Therefore, compared with directly assembling a vibrating device with an independent tubular structure with an optical fiber, the assembly cost of using four micro piezoelectric ceramic sheets is lower and more flexible. When facing different applications, micro piezoelectric ceramic sheets of different sizes can be used at any time to make a micro-scanning tube or the length and resonant frequency of the optical fiber cantilever can be changed by a spiral regulator to meet different imaging performance requirements. The assembly structure also makes it very convenient to fix optical fiber ferrules of different sizes inside the scanner, thereby significantly improving the central symmetry and stability of the system, which is of great significance for the practical application of nonlinear microscopic imaging technology.

[0049] The above specific embodiments do not limit the technical solutions of the present invention. For those skilled in the art, they can be improved and changed according to the above invention content. Any modification, equivalent replacement, improvement or change made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A tunable fiber scanner for an all-fiber nonlinear microscopic imager, characterized in that: It includes a scanning component and a driving component; The scanning assembly 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 relative to 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.

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

3. The tunable fiber scanner of the all-fiber 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.

4. The tunable fiber scanner of the all-fiber 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.

5. The tunable fiber scanner of the all-fiber 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.

6. The tunable fiber scanner of the all-fiber 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.

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

8. The tunable fiber scanner of the all-fiber 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.

9. The tunable fiber scanner of the all-fiber 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 during assembly, it forms a tight fit with the inner diameter of the micro scanning square tube assembled from the micro piezoelectric ceramic sheet.

10. 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.

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