Imaging method for penetrating deeper scattering medium

Abstract

The invention belongs to the technical field of optical scattering imaging. An imaging method for penetrating a deeper scattering medium comprises the following steps: inserting an optical fiber into a hard steel pipe to form a hard multimode optical fiber; then, a hard multimode optical fiber imaging device for realizing penetration of a deeper scattering medium based on a transmission matrix and a hard optical fiber probe or a hard multimode optical fiber imaging device for realizing penetration of a deeper scattering medium based on non-intrusive iterative feedback wavefront shaping and a hard optical fiber probe is built; the rigid multimode optical fiber is used as a probe to be inserted into to-be-scanned bodies in different depth ranges for scanning to realize scanning imaging of the to-be-scanned bodies in different depth ranges; the method is not easily influenced by the environment, and stable imaging of penetrating through a deeper scattering medium can be realized.

Description

Technical Field

[0001] The invention belongs to the technical field of optical scattering imaging. Background Art

[0002] Multimode optical fiber is often regarded as a scattering medium due to its modal scrambling. The development of wavefront shaping technology has achieved the control of wavefront, so that light can be focused at the output end of the optical fiber. However, when the optical fiber is affected by some environmental factors (such as fiber bending, temperature changes, etc.), interference and coupling between modes are likely to occur, and the focus at the output end of the optical fiber cannot maintain its original shape, making it difficult to achieve imaging when penetrating deeper scattering media. Therefore, it is urgent to develop a new technology to effectively overcome the defect of multimode optical fiber being susceptible to interference. Summary of the invention

[0003] The technical problem to be solved by the present invention is: how to solve the problem mentioned in the background technology that multimode optical fiber is easily affected by the environment when penetrating deeper scattering imaging, and provide an imaging device that achieves strong anti-interference, less damage and deeper depth. Since the multimode optical fiber is small in size and can be bent at a very small angle, we embed the multimode optical fiber into a hard steel pipe, and one end is used to insert it into different depths of biological tissue for imaging. However, there are mode coupling and mode dispersion in the multimode optical fiber. When light is transmitted through the multimode optical fiber, the mode scrambling will cause the image to be distorted when propagating in the multimode optical fiber, that is, speckle is observed at the output end of the multimode optical fiber. This will bring some challenges to actual imaging. The wavefront shaping technology can effectively compensate for this effect. The required diffraction-limited focus can be generated at any position of the output end of the optical fiber through the transmission matrix or iterative wavefront shaping. By superimposing a tilted phase grating on the digital micromirror device, the focus is grating scanned on the object at the far end of the optical fiber, and the total intensity of the light returned through the optical fiber is recorded to achieve imaging based on grating scanning. The hard steel needle tube combined with multi-mode optical fiber can effectively overcome the problem of its susceptibility to environmental disturbances, and is expected to achieve strong anti-interference, less damage and deeper depth imaging in the field of medical endoscopy.

[0004] The technical solution adopted by the present invention is: an imaging method for penetrating deeper scattering media, by inserting an optical fiber into a hard steel pipe to form a hard multimode optical fiber 10, and then building a hard multimode optical fiber imaging device based on a transmission matrix and a hard optical fiber probe to achieve penetration of deeper scattering media or a hard multimode optical fiber imaging device based on non-invasive iterative feedback wavefront shaping and a hard optical fiber probe to achieve penetration of deeper scattering media, inserting the hard multimode optical fiber 10 as a probe into a to-be-scanned body 11 of different depth ranges for scanning to achieve scanning imaging of different depth ranges of the to-be-scanned body 11; based on the transmission matrix and The rigid multimode optical fiber imaging device for realizing penetration of deeper scattering media by a rigid optical fiber probe includes a continuous laser 1, a beam expander 2, a digital micromirror device 3, a first lens 4, an aperture diaphragm 5, a second lens 6, a reflector 7, a dichroic mirror 8, a first microscope objective 9, a rigid multimode optical fiber 10, a second microscope objective 12, a third lens 13, a first array photodetector 14, a fourth lens 15, a second array photodetector 16, and a computer 17. The digital micromirror device 3 is connected to the computer 17. The laser emitted by the continuous laser 1 is expanded by the beam expander 2 and then transmitted to the digital micromirror device 3 for modulation. The laser modulated by the digital micromirror device 3 passes through the first lens 4, the aperture diaphragm 5, and the second lens 6 in sequence. The aperture diaphragm 5 filters out the light other than the diffracted first-order light. The 4f system composed of the first lens 4 and the second lens 6 reflects the light through the reflector 7 and transmits it through the dichroic mirror 8, and then conjugates it to the entrance pupil of the first microscope objective 9. The first microscope objective 9 couples the light into the rigid multimode optical fiber 10. The second microscope objective 12 receives the light from the rigid multimode optical fiber 10 and focuses the light through the third lens 13 to the first array photodetector 14. The first array photodetector 14 records the received light signal and transmits it to Computer 17, when the rigid multimode optical fiber 10 is used as a probe, the fluorescence excited in the object to be scanned 11 is collected by the rigid multimode optical fiber 10 to form a fluorescence speckle, and then passes through the first microscope objective lens 9, is reflected by the dichroic mirror 8, enters the fourth lens 15, and is focused to the second array photodetector 16. The second array photodetector 16 records the received light signal and transmits it to the computer 17. The computer 17 uses a deconvolution or phase recovery algorithm to achieve reconstruction, obtains a scanned image of the object to be scanned 11, and changes the depth of the rigid multimode optical fiber 10 in the object to be scanned 11 to obtain a scanned image of the object to be scanned 11 in different depth ranges;A rigid multimode fiber imaging device based on non-invasive iterative feedback wavefront shaping and rigid fiber probe for penetrating deeper scattering media includes a continuous laser 1, a beam expander 2, a digital micromirror device 3, a first lens 4, an aperture diaphragm 5, a second lens 6, a reflector 7, a dichroic mirror 8, a first microscope objective 9, a rigid multimode fiber 10, a fourth lens 15, a second array photodetector 16, and a computer 17. The digital micromirror device 3 is connected to the computer 17. The laser emitted by the continuous laser 1 is expanded by the beam expander 2 and then transmitted to the digital micromirror device 3 for modulation. The laser modulated by the digital micromirror device 3 passes through the first lens 4, the aperture diaphragm 5, and the second lens 6 in sequence. The aperture diaphragm 5 filters out light other than the diffracted first-order light. The 4f system composed of the first lens 4 and the second lens 6 reflects the light through the reflector 7 and the dichroic mirror 8. After transmission, it is conjugated to the entrance pupil of the first microscope objective 9. The first microscope objective 9 couples the light into the rigid multimode optical fiber 10. The rigid multimode optical fiber 10 is inserted as a probe into the object to be scanned 11. The excited fluorescence is collected by the rigid multimode optical fiber 10 to form a fluorescence speckle. After passing through the first microscope objective 9, it is reflected by the dichroic mirror 8 and enters the fourth lens 15 to be focused to the second array photodetector 16. The second array photodetector 16 records the received light signal and transmits it to the computer 17. The fluorescence speckle signal in the light signal recorded by the second array photodetector 16 is used as feedback to iterate to form a focus point. The focus point is used to perform raster scanning imaging on the object to be scanned 11 to obtain the scanning imaging of the object to be scanned 11. The depth of the rigid multimode optical fiber 10 in the object to be scanned 11 is changed to obtain scanning imaging of the object to be scanned 11 in different depth ranges. ;

[0005] The hard multimode optical fiber imaging device based on the transmission matrix and the hard optical fiber probe can penetrate deeper into the scattering medium to obtain the scanning image of the object to be scanned 11, which specifically includes the following steps:

[0006] Step 1: Select the Hardmard (matrix) basis to modulate the target (digital micromirror device) spatial wavefront, with a resolution parameter of N×N and a phase shift step number of

[0007] Step 2: Based on the modulation in step 1, a Hardmard modulation basis with a resolution of N×N is calculated and generated, and a multi-step phase shift pattern with a resolution of N×N is generated;

[0008] Step 3: Superimpose the multi-step phase shift pattern generated in step 2 onto the N×N Hardmard modulation basis generated in step 2 to produce the final A self-interfering coding mode;

[0009] Step 4: Convert the The phase-shifted coding patterns are sequentially loaded onto the digital micromirror device 3. At this time, the total number of micromirrors of the digital micromirror device 3 is set to 512×512, and the target spatial wavefront is modulated. The aperture diaphragm 5 filters out the first order of diffraction. The 4f system composed of the first lens 4 and the second lens 6 reduces the beam diameter to 3 / 4 of the original, so that the beam diameter can match the entrance pupil diameter of the objective lens. The laser is coupled into the hard multimode optical fiber 10 through the first microscope objective lens 9, and the speckle from the optical fiber is collected into the first array photodetector 14 in the calibration stage through the second microscope objective lens 12 and the third lens 13. A total of The corresponding speckle intensity I out Finally, the output light field E is solved by combining the four-step phase shift formula out According to E out =TE in , the transmission matrix T is solved, and the system calibration phase is now completed;

[0010] Step 5: According to the transfer matrix T calculated in step 4, conjugate transpose thereof can be obtained to obtain a focus or even multiple focus points at any position on the output plane;

[0011] Step six, imaging stage, after the system is calibrated, the fluorescently dyed object to be scanned 11 is placed at the output end of the rigid multimode optical fiber, and the focal point generated in step five is used to superimpose a tilted phase grating on the digital micromirror device 3 to realize focal illumination of different positions of the fluorescently dyed object to be scanned 11. The fluorescent light is excited by the laser focus, and the excited fluorescence is collected by the second array photodetector 16 at the near end of the optical fiber through the rigid multimode optical fiber 10, and the object is reconstructed using a deconvolution or phase recovery algorithm. Since the optical fiber is not easily affected by environmental disturbances, the optical fiber probe can use the focus to move within the object to be scanned 11 and perform grating scanning imaging at different depth ranges.

[0012] The hard multimode fiber imaging device based on non-invasive iterative feedback wavefront shaping and hard fiber probe can penetrate deeper scattering media to obtain scanning imaging of the object to be scanned 11, which specifically includes the following steps.

[0013] Step 1: The computer 17 controls the digital micromirror device 3 to modulate the wavefront phase of the incident light field, and the aperture diaphragm 5 filters out the light outside the first order of diffraction. The 4f system composed of the first lens 4 and the second lens 6 reduces the beam diameter to 3 / 4 of the original diameter, so that the beam diameter can match the entrance pupil diameter of the first microscope objective lens 9. Then, the first microscope objective lens 9 couples the laser into the hard multimode optical fiber 10;

[0014] Step 2: The outgoing light field of the rigid multimode optical fiber 10 excites the fluorescent target in the object to be scanned 11, and the excited fluorescence passes through the rigid multimode optical fiber 10 in the reverse direction to form a fluorescent speckle, which is recorded by the second planar array photoelectric detector 16 at the near end of the optical fiber;

[0015] Step 3: The computer 17 runs an iterative optimization algorithm, and the optimization index is the contrast of the recorded fluorescent speckle Where σ(I) is the standard deviation of the speckle pattern on the array photodetector, is the mean value of the speckle pattern on the array photodetector;

[0016] Step 4: After reaching the preset number of iterations, the iterative optimization algorithm stops iterating, and the number of iterations is set before the iterative process starts. At this time, the optimized incident light field non-invasively generates an initial fluorescent focus behind the rigid multimode optical fiber as a "guide star";

[0017] Step 5: After achieving non-invasive focusing, the iterative optimization algorithm stops iterating, and by superimposing a tilted phase grating on the digital micromirror device 3 and tilting the incident light field, efficient scanning with the focus within the object to be scanned 11 is achieved. The backscattered light obtained after scanning is collected by the rigid multimode optical fiber 10, and the corresponding fluorescent speckle is recorded by the second array photodetector 16. The fluorescent speckle is reconstructed using a phase recovery algorithm or a deconvolution algorithm to achieve scanning imaging at different depth ranges.

[0018] The beneficial effects of the present invention are as follows: in the present invention, a multimode optical fiber is placed in a hard thin steel tube to form a hard multimode optical fiber to prevent it from being easily affected by the environment. The present invention builds a hard multimode optical fiber imaging device based on a transmission matrix and a hard optical fiber probe to achieve penetration of deeper scattering media, or a hard multimode optical fiber imaging device based on non-invasive iterative feedback wavefront shaping and a hard optical fiber probe to achieve penetration of deeper scattering media, and realizes scanning imaging of different depth ranges of the object to be scanned, which is a kind of imaging with strong anti-interference, less damage and deeper depth. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a diagram of a rigid multimode fiber imaging device based on a transmission matrix and a rigid fiber probe to achieve deeper penetration into scattering media;

[0020] Figure 2 This is a diagram of a rigid multimode fiber imaging device based on non-invasive iterative feedback wavefront shaping and a rigid fiber probe that can penetrate deeper into scattering media;

[0021] Figure 3 is a schematic diagram of a rigid multimode fiber probe;

[0022] In the figure, 1-continuous laser, 2-beam expander, 3-digital micromirror device, 4-first lens, 5-aperture stop, 6-second lens, 7-reflector, 8-dichroic mirror, 9-first microscope objective lens, 10-rigid multimode optical fiber, 11-object to be scanned, 12-second microscope objective lens, 13-third lens, 14-first array photodetector, 15-fourth lens, 16-second array photodetector, 17-computer. Specific implementation plan

[0023] The present invention is further described in detail below with reference to the accompanying drawings and embodiments.

[0024] Example 1

[0025] The present invention discloses an imaging method for penetrating deeper scattering media, which uses a hard steel needle tube combined with a multimode optical fiber to form a hard multimode optical fiber, and builds a hard multimode optical fiber imaging device based on a transmission matrix and a hard optical fiber probe to achieve penetration of deeper scattering media, thereby achieving scanning imaging of different depth ranges of a scanned object 11. In this embodiment, the scanned object 11 is a fluorescently stained mouse brain, and the wavelength of the continuous laser 1 is 532nm.

[0026] like Figure 1 As shown, a method for imaging deeper into a scattering medium is to insert an optical fiber into a hard steel tube to form a hard multimode optical fiber 10 (such as Figure 3As shown, an optical fiber is inserted into a stainless steel pipe to form a hard optical fiber probe, and the short end is used for scanning and imaging. The outer shell of the hard steel pipe is made of stainless steel material. The optical fiber is inserted into the steel pipe, and the two ends of the steel pipe can be adjusted by rotation to clamp the optical fiber). Then, a hard multimode optical fiber imaging device is built based on a transmission matrix and a hard optical fiber probe to achieve penetration of deeper scattering media. The hard multimode optical fiber 10 is inserted as a probe into a to-be-scanned object 11 of different depth ranges for scanning to achieve scanning and imaging of the to-be-scanned object 11 at different depth ranges; based on the transmission matrix and the hard optical fiber probe, penetration is achieved. The rigid multimode optical fiber imaging device for penetrating deeper scattering media comprises a continuous laser 1, a beam expander 2, a digital micromirror device 3, a first lens 4, an aperture stop 5, a second lens 6, a reflector 7, a dichroic mirror 8, a first microscope objective 9, a rigid multimode optical fiber 10, a second microscope objective 12, a third lens 13, a first array photodetector 14, a fourth lens 15, a second array photodetector 16, and a computer 17. The digital micromirror device 3 is connected to the computer 17. The laser emitted by the continuous laser 1 is expanded by the beam expander 2 and then transmitted to the digital micromirror device 3 for modulation. The laser modulated by the component 3 sequentially passes through the first lens 4, the aperture diaphragm 5, and the second lens 6. The aperture diaphragm 5 filters out the light other than the diffracted first-order light. The 4f system composed of the first lens 4 and the second lens 6 reflects the light through the reflector 7 and transmits the light through the dichroic mirror 8, and then conjugates the light to the entrance pupil of the first microscope objective 9. The first microscope objective 9 couples the light into the rigid multimode optical fiber 10. The second microscope objective 12 receives the light from the rigid multimode optical fiber 10 and focuses the light through the third lens 13 to the first array photodetector 14. The first array photodetector 14 records the received light signal and transmits it to the computer 1. 7. When the rigid multimode optical fiber 10 is used as a probe, the fluorescence excited in the object to be scanned 11 is collected by the rigid multimode optical fiber 10 to form a fluorescence speckle, and then passes through the first microscope objective lens 9, is reflected by the dichroic mirror 8, enters the fourth lens 15, and is focused to the second array photodetector 16. The second array photodetector 16 records the received light signal and transmits it to the computer 17. The computer 17 reconstructs the image of the object to be scanned 11 by using a deconvolution or phase recovery algorithm, and obtains the scanning image of the object to be scanned 11. The depth of the rigid multimode optical fiber 10 in the object to be scanned 11 is changed to obtain the scanning image of the object to be scanned 11 in different depth ranges.

[0027] A hard multimode fiber imaging device based on a transmission matrix and a hard fiber probe is used to penetrate deeper scattering media to obtain scanning imaging of the object to be scanned 11. The specific steps include the following: Step 1: Select the Hardmard basis to modulate the target spatial wavefront, with a resolution parameter of N×N and a phase shift step number of Step 2: Based on the modulation in step 1, a Hardmard modulation basis with a resolution of N×N is calculated and generated, and a multi-step phase shift pattern with a resolution of N×N is generated; N is a set value.

[0028] Step 3: Superimpose the multi-step phase shift pattern generated in step 2 onto the N×N Hardmard modulation basis generated in step 2 to produce the final A self-interfering coding mode; is the set value.

[0029] Step 4: Convert the The phase-shifted coding patterns are sequentially loaded onto the digital micromirror device 3. At this time, the total number of micromirrors of the digital micromirror device 3 is set to 512×512, and the target spatial wavefront is modulated. The aperture diaphragm 5 filters out the first order of diffraction. The 4f system composed of the first lens 4 and the second lens 6 reduces the beam diameter to 3 / 4 of the original, so that the beam diameter can match the entrance pupil diameter of the objective lens. The laser is coupled into the hard multimode optical fiber 10 through the first microscope objective lens 9, and the speckle from the optical fiber is collected into the first array photodetector 14 in the calibration stage through the second microscope objective lens 12 and the third lens 13. A total of The corresponding speckle intensity I out Finally, the output light field E is solved by combining the four-step phase shift formula out According to E out =TE in , the transmission matrix T is solved, and the system calibration phase is now completed; E in is the input light field.

[0030] Step 5: According to the transfer matrix T calculated in step 4, conjugate transpose thereof can be obtained to obtain a focus or even multiple focus points at any position on the output plane;

[0031] Step six, imaging stage, after the system is calibrated, the fluorescently dyed object to be scanned 11 is placed at the output end of the rigid multimode optical fiber, and the focal point generated in step five is used to superimpose a tilted phase grating on the digital micromirror device to achieve focal illumination of different positions of the fluorescently dyed object to be scanned 11. The fluorescence is excited by the laser focus, and the excited fluorescence is collected by the second array photodetector 16 at the near end of the rigid multimode optical fiber 10, and the object is reconstructed using a deconvolution or phase recovery algorithm. Since the optical fiber is not easily affected by environmental disturbances, the optical fiber probe can use the focus to move within the object to be scanned 11 and perform grating scanning imaging at different depth ranges.

[0032] Example 2

[0033] The present invention discloses an imaging method for penetrating deeper scattering media, which utilizes a hard steel needle tube combined with a multimode optical fiber to form a hard multimode optical fiber, and realizes a hard multimode optical fiber imaging device for penetrating deeper scattering media based on non-invasive iterative feedback wavefront shaping and a hard optical fiber probe, thereby realizing scanning imaging of different depth ranges of a scanned object 11. In this embodiment, the scanned object 11 is a fluorescently stained mouse brain, and the wavelength of the continuous laser 1 is 532nm.

[0034] like Figure 2 As shown, a method for imaging deeper into a scattering medium is provided, wherein a hard multimode optical fiber 10 is formed by inserting an optical fiber into a hard steel pipe, and then a hard multimode optical fiber imaging device is constructed based on non-invasive iterative feedback wavefront shaping and a hard optical fiber probe to achieve penetration of a deeper scattering medium, and the hard multimode optical fiber 10 is inserted as a probe into a to-be-scanned body 11 of different depth ranges for scanning to achieve scanning imaging of the to-be-scanned body 11 in different depth ranges; the hard multimode optical fiber imaging device based on non-invasive iterative feedback wavefront shaping and a hard optical fiber probe to achieve penetration of a deeper scattering medium comprises a continuous laser 1, a beam expander 2, a digital micromirror device 3, a first lens 4, an aperture stop 5, a second lens 6, a reflector 7, a dichroic mirror 8, a first microscope objective 9, a hard multimode optical fiber 10, a fourth lens 15, a second array photodetector 16, and a computer 17, wherein the digital micromirror device 3 is connected to the computer 17, and the laser emitted by the continuous laser 1 is expanded by the beam expander 2 and then transmitted to the digital micromirror device 3 for modulation, and the laser modulated by the digital micromirror device 3 is sequentially transmitted to the digital micromirror device 3 for modulation. The first lens 4, the aperture diaphragm 5, and the second lens 6 are sequentially passed through the first lens 4, the aperture diaphragm 5, and the second lens 6. The aperture diaphragm 5 filters out the light except the diffracted first-order light. The 4f system composed of the first lens 4 and the second lens 6 reflects the light through the reflector 7 and transmits the light through the dichroic mirror 8, and then conjugates the light to the entrance pupil of the first microscope objective 9. The first microscope objective 9 couples the light into the rigid multimode optical fiber 10. The rigid multimode optical fiber 10 is inserted into the object to be scanned 11 as a probe. The excited fluorescence is collected by the rigid multimode optical fiber 10 to form a fluorescent speckle. After passing through the first microscope objective 9, it is conjugated by the dichroic mirror. 8 is reflected and enters the fourth lens 15 to be focused onto the second array photodetector 16, the second array photodetector 16 records the received light signal and transmits it to the computer 17, and the fluorescent speckle signal in the light signal recorded by the second array photodetector 16 is used as feedback to iterate to form a focusing point, and the focusing point is used to perform raster scanning imaging on the object to be scanned 11 to obtain a scanning image of the object to be scanned 11, and the depth of the rigid multimode optical fiber 10 in the object to be scanned 11 is changed to obtain scanning imaging of the object to be scanned 11 in different depth ranges.

[0035] The hard multimode fiber imaging device based on non-invasive iterative feedback wavefront shaping and hard fiber probe can penetrate deeper scattering media to obtain scanning imaging of the object to be scanned 11, which specifically includes the following steps.

[0036] Step 1: The computer 17 controls the digital micromirror device 3 to modulate the wavefront phase of the incident light field, and the aperture diaphragm 5 filters out the light outside the first order of diffraction. The 4f system composed of the first lens 4 and the second lens 6 reduces the beam diameter to 3 / 4 of the original diameter, so that the beam diameter can match the entrance pupil diameter of the first microscope objective lens 9. Then, the first microscope objective lens 9 couples the laser into the hard multimode optical fiber 10;

[0037] Step 2: The outgoing light field of the rigid multimode optical fiber 10 excites the fluorescent target in the object to be scanned 11, and the excited fluorescence passes through the rigid multimode optical fiber 10 in the reverse direction to form a fluorescent speckle, which is recorded by the second planar array photoelectric detector 16 at the near end of the optical fiber;

[0038] Step 3: The computer 17 runs an iterative optimization algorithm, and the optimization index is the contrast of the recorded fluorescent speckle Where σ(I) is the standard deviation of the speckle pattern on the array photodetector, is the mean value of the speckle pattern on the array photodetector;

[0039] Step 4: After reaching the preset number of iterations, the iterative optimization algorithm stops iterating, and the number of iterations is set before the iterative process starts. At this time, the optimized incident light field non-invasively generates an initial fluorescent focus behind the rigid multimode optical fiber as a "guide star";

[0040] Step 5: After achieving non-invasive focusing, the iterative optimization algorithm stops iterating, and by superimposing a tilted phase grating on the digital micromirror device 3 and tilting the incident light field, efficient scanning with the focus within the object to be scanned 11 is achieved. The backscattered light obtained after scanning is collected by the rigid multimode optical fiber 10, and the corresponding fluorescent speckle is recorded by the second array photodetector 16. The fluorescent speckle is reconstructed using a phase recovery algorithm or a deconvolution algorithm to achieve scanning imaging at different depth ranges.

[0041] The above is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, some improvements and modifications without departing from the principle of the present invention should also be regarded as the protection scope of the present invention.

Claims

1. An imaging method for penetrating deeper scattering media, characterized in that: The optical fiber is inserted into a hard steel pipe to form a hard multimode optical fiber (10), and then a hard multimode optical fiber imaging device based on a transmission matrix and a hard optical fiber probe is constructed to achieve penetration of a deeper scattering medium, or a hard multimode optical fiber imaging device based on non-invasive iterative feedback wavefront shaping and a hard optical fiber probe is constructed to achieve penetration of a deeper scattering medium. The hard multimode optical fiber (10) is inserted as a probe into a to-be-scanned body (11) of different depth ranges for scanning to achieve scanning imaging of the to-be-scanned body (11) in different depth ranges. The hard multimode optical fiber imaging device based on a transmission matrix and a hard optical fiber probe to achieve penetration of a deeper scattering medium comprises a continuous laser (1), a beam expander (2), a digital micromirror device (3), a first lens (4), an aperture stop (5), a second lens (6), a reflector (7), a dichroic mirror (8), a first microscope objective lens (9), a rigid multimode optical fiber (10), a second microscope objective lens (12), a third lens (13), a first array photodetector (14), a fourth lens (15), a second array photodetector (16), and a computer (17). The digital micromirror device (3) is connected to the computer (17). The laser light emitted by the continuous laser (1) is expanded by the beam expander (2) and then transmitted to the digital micromirror device (3) for modulation. The laser light modulated by the digital micromirror device (3) is sequentially transmitted through the first A first lens (4), an aperture stop (5), and a second lens (6), wherein the aperture stop (5) filters out light other than diffracted first-order light, and a 4f system composed of the first lens (4) and the second lens (6) reflects the light through a reflector (7) and transmits the light through a dichroic mirror (8) and then conjugates the light to an entrance pupil of a first microscope objective lens (9), and the first microscope objective lens (9) couples the light into a rigid multimode optical fiber (10), and the second microscope objective lens (12) receives the light transmitted from the rigid multimode optical fiber (10) and focuses the light through a third lens (13) to a first planar array photodetector (14), and the first planar array photodetector (14) records the received light signal and transmits it to a computer (17). When the rigid multimode optical fiber (10) is used as a probe, the fluorescence excited in the object to be scanned (11) is collected by the rigid multimode optical fiber (10) to form a fluorescence speckle, which passes through the first microscope objective lens (9), is reflected by the dichroic mirror 8, enters the fourth lens (15), and is focused to the second array photodetector (16). The second array photodetector (16) records the received light signal and transmits it to the computer (17). The computer (17) uses a deconvolution or phase recovery algorithm to achieve reconstruction, obtains a scanned image of the object to be scanned (11), and changes the depth of the rigid multimode optical fiber (10) in the object to be scanned (11) to obtain a scanned image of the object to be scanned (11) in different depth ranges.The rigid multimode fiber imaging device based on non-invasive iterative feedback wavefront shaping and rigid fiber probe for penetrating deeper scattering media comprises a continuous laser (1), a beam expander (2), a digital micromirror device (3), a first lens (4), an aperture stop (5), a second lens (6), a reflector (7), a dichroic mirror (8), a first microscope objective (9), a rigid multimode fiber (10), a fourth lens (15), a second array photodetector (16), and a computer (17). The digital micromirror device (3) is connected to the computer (17). The laser light emitted by the continuous laser (1) is expanded by the beam expander (2) and then transmitted to the digital micromirror device (3) for modulation. The laser light modulated by the digital micromirror device (3) passes through the first lens (4), the aperture stop (5), and the second lens (6) in sequence. The aperture stop (5) filters out light other than diffracted first-order light. The 4f system composed of the first lens (4) and the second lens (6) transmits the light through the reflector (7). After reflection and transmission through the dichroic mirror (8), the light is conjugated to the entrance pupil of the first microscope objective lens (9). The first microscope objective lens (9) couples the light into the rigid multimode optical fiber (10). The rigid multimode optical fiber (10) is inserted into the object to be scanned (11) as a probe. The excited fluorescence is collected by the rigid multimode optical fiber (10) to form a fluorescence speckle. After passing through the first microscope objective lens (9), the light is reflected by the dichroic mirror 8 and enters the fourth lens (15). The light is focused to the second array photodetector (16). The second array photodetector (16) records the received light signal and transmits it to the computer (17). The fluorescence speckle signal in the light signal recorded by the second array photodetector (16) is used as feedback to iterate to form a focus point. The focus point is used to perform raster scanning imaging on the object to be scanned (11) to obtain a scanning image of the object to be scanned (11). The depth of the rigid multimode optical fiber (10) in the object to be scanned (11) is changed to obtain scanning images of the object to be scanned (11) in different depth ranges.

2. The imaging method for penetrating deeper scattering media according to claim 1, characterized in that: A hard multimode optical fiber imaging device based on a transmission matrix and a hard optical fiber probe is used to penetrate deeper scattering media to obtain scanning imaging of a body to be scanned (11), which specifically includes the following steps: Step 1: Select the Hardmard basis to modulate the target spatial wavefront, with a resolution parameter of N×N and a phase shift step number of N and is a natural number; Step 2: Based on the modulation in step 1, a Hardmard modulation basis with a resolution of N×N is calculated and generated, and a multi-step phase shift pattern with a resolution of N×N is generated; Step 3: Superimpose the multi-step phase shift pattern generated in step 2 onto the N×N Hardmard modulation basis generated in step 2 to produce the final A self-interfering coding mode; Step 4: Convert the The phase-shifted coding patterns are sequentially loaded onto the digital micromirror device (3). At this time, the total number of micromirrors of the digital micromirror device (3) is set to 512×512, and the target spatial wavefront is modulated. The aperture diaphragm (5) filters out the first order of diffraction. The 4f system composed of the first lens (4) and the second lens (6) reduces the beam diameter to 3 / 4 of the original diameter so that the beam diameter can match the entrance pupil diameter of the objective lens. The laser is coupled into the hard multimode optical fiber (10) through the first microscope objective lens (9). The speckle from the optical fiber is collected into the first array photodetector (14) in the calibration stage through the second microscope objective lens (12) and the third lens (13). A total of The corresponding speckle intensity I out Finally, the output light field E is solved by combining the four-step phase shift formula out According to E out =TE in , the transmission matrix T is solved, and the system calibration phase is now completed; Step 5: According to the transfer matrix T calculated in step 4, conjugate transpose thereof can be obtained to obtain a focus or even multiple focus points at any position on the output plane; Step 6, imaging stage, after the system is calibrated, a fluorescently dyed object to be scanned (11) is placed at the output end of the rigid multimode optical fiber, and the focal point generated in step 5 is used to superimpose a tilted phase grating on the digital micromirror device (3) to achieve focal illumination of different positions of the fluorescently dyed object to be scanned (11). The fluorescent light is excited by the laser focus, and the excited fluorescence is collected by the second array photodetector (16) at the near end of the optical fiber through the rigid multimode optical fiber (10), and the object is reconstructed using a deconvolution or phase recovery algorithm. Since the optical fiber is not easily affected by environmental disturbances, the optical fiber probe can use the focus to move within the object to be scanned (11) and perform grating scanning imaging at different depth ranges.

3. The imaging method for penetrating deeper scattering media according to claim 1, characterized in that: A hard multimode optical fiber imaging device based on non-invasive iterative feedback wavefront shaping and a hard optical fiber probe to achieve penetration into a deeper scattering medium obtains scanning imaging of a body to be scanned (11) and specifically comprises the following steps Step 1: The computer (17) controls the digital micromirror device (3) to modulate the wavefront phase of the incident light field, the aperture diaphragm (5) filters out the light outside the first order of diffraction, and the 4f system composed of the first lens (4) and the second lens (6) reduces the beam diameter to 3 / 4 of the original diameter so that the beam diameter can match the entrance pupil diameter of the first microscope objective lens (9), and then the first microscope objective lens (9) couples the laser into the hard multimode optical fiber (10); Step 2: The output light field of the rigid multimode optical fiber (10) excites the fluorescent target in the object to be scanned (11), and the excited fluorescence passes through the rigid multimode optical fiber (10) in the reverse direction to form a fluorescent speckle, which is recorded by a second array photoelectric detector (16) at the near end of the optical fiber; Step 3: The computer (17) runs an iterative optimization algorithm, and the optimization index is the contrast of the recorded fluorescent speckle Where σ(I) is the standard deviation of the speckle pattern on the array photodetector, is the mean value of the speckle pattern on the array photodetector; Step 4: After reaching the preset number of iterations, the iterative optimization algorithm stops iterating. The number of iterations is set before the iterative process starts. At this time, the optimized incident light field non-invasively generates an initial fluorescent focus behind the rigid multimode optical fiber as a "guide star"; Step 5: After achieving non-invasive focusing, the iterative optimization algorithm stops iterating, and by superimposing a tilted phase grating on the digital micromirror device (3), the incident light field is tilted to achieve efficient scanning with the focus in the object to be scanned (11). The backscattered light obtained after scanning is collected by the hard multimode optical fiber (10), and the corresponding fluorescent speckle is recorded by the second array photodetector (16). The fluorescent speckle is reconstructed by using a phase recovery algorithm or a deconvolution algorithm to achieve scanning imaging in different depth ranges.

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