Large-depth-of-field opto-acoustic fusion confocal microscopy system and method based on light field regulation and control

Abstract

The invention relates to a large depth-of-field photoacoustic fusion confocal microscopy system and method based on light field regulation, the system comprises an illumination system, a detection system and an imaging system, the illumination system comprises a phase modulation optical assembly and an illumination beam power measurement assembly, the phase modulation optical assembly comprises a first lens, a half-wave plate, a first polarization splitting prism PBS, a second lens, a first quarter-wave plate and an optical module, and the optical module is used for modulating a diffusion function of an illumination point to generate a self-acceleration light beam; the self-accelerating beam is generated based on a cubic phase or an exponential phase or a transformed exponential phase. Compared with the prior art, the method has the advantages that the problem that high depth resolution and high resolution cannot be simultaneously achieved in chip defect detection is solved, and the like.

Description

Technical Field

[0001] The present invention relates to the field of optical nondestructive testing, and in particular to a large-depth-of-field photoacoustic fusion confocal microscopy system and method based on light field regulation. Background Art

[0002] With the rapid development of information technology, chips play a vital role in the development of modern industry, and modern industry has increasingly higher requirements for chip defect detection. In chip defect detection, flip chips with complex structures may have defects such as sol defects, lead lift or missing, voids, cracks, and solder missing. The presence of defects can affect the performance of chips in computers, automobiles, and other electronic devices, and is crucial for high-end manufacturing. In order to ensure quality control compatible with rapid production, several non-destructive non-destructive testing techniques have been proposed to detect such defects in the packaging process. For example, conventional optical microscopes are limited to surface defect detection and have poor penetration. Scanning acoustic microscopy can detect defects as deep as 200μm, but requires long scanning times and the chip must be covered in an ultrasonic coupler first. X-ray computed tomography can reconstruct three-dimensional defects at considerable depth, but requires ionizing radiation, long scanning times, and parallel computing. Surface acoustic wave technology can also penetrate to a depth of 200μm, but requires piezoelectric elements with limited bandwidth or air-coupled sensors with low sensitivity and expensive scanning laser vibrometers. Ultrafast optical laser ultrasonic technology can detect defects up to several millimeters deep with submicron resolution, but the scanning speed is limited by the need for a motorized stage to scan. Therefore, current nondestructive testing technologies cannot achieve both high depth resolution and high resolution at the same time. Summary of the invention

[0003] The purpose of the present invention is to provide a large depth of field photoacoustic fusion confocal microscopy system and method based on light field regulation in order to achieve both high depth resolution and high resolution. The point spread function of the system is modulated at the illumination end to expand the axial size of its illumination point spread function and enable it to have the ability of large depth of field detection.

[0004] The purpose of the present invention can be achieved by the following technical solutions:

[0005] A large-depth-of-field photoacoustic fusion confocal microscopy system based on light field regulation, the system comprising an illumination system, a detection system and an imaging system, wherein the illumination system comprises a phase modulation optical component and an illumination beam power measurement component, wherein the phase modulation optical component comprises a first lens, a half-wave plate, a first polarization beam splitter prism PBS, a second lens, a first quarter-wave plate and an optical module, wherein the optical module is used to modulate the illumination point spread function to generate a self-accelerating beam, wherein the self-accelerating beam is generated based on a cubic phase or an exponential phase or a transformed exponential phase; the illumination beam power measurement component comprises a first lens, a half-wave plate, a first polarization beam splitter prism PBS, a second lens and a photodetector;

[0006] The illumination system further comprises a laser, a second lens, a pinhole, a sixth lens, a dichroic mirror, an XY scanning galvanometer, a scanning lens, a tube lens, a reflector and an objective lens;

[0007] The detection system includes a superluminescent diode, a reflective collimator, a third lens, a fourth lens, a second polarization beam splitter prism PBS, a second quarter wave plate, a dichroic mirror, an XY scanning galvanometer, a scanning lens, a tube lens, a reflector and an objective lens;

[0008] The imaging system comprises a photodetector, a fifth lens, a long-wave filter, a polarization beam splitter prism PBS, a second quarter-wave plate, a dichroic mirror, an XY scanning galvanometer, a scanning lens, a tube lens, a reflector and an objective lens.

[0009] Further, the cubic phase is:

[0010] P(x, y) = α((x-β) 3 -(y-β) 3 )

[0011] Among them, α and β are design parameters, and x and y represent the variables propagated on the x-axis and y-axis.

[0012] Furthermore, the exponential phase is:

[0013] P(x, y) = αx·exp(βx 2 )+ay·exp(βy 2 )

[0014] Among them, α and β are design parameters, and x and y represent the variables propagated on the x-axis and y-axis.

[0015] Furthermore, the transformed exponential phase is:

[0016] P(x, y) = α(xy) exp(β(xy) 2 )+α(x+y)·exp(β(x+y)2 )

[0017] P(x, y) = α(xy) exp(β(xy) 2 )-α(x+y)·exp(β(x+y) 2 )

[0018] Among them, α and β are design parameters, and x and y represent the variables propagated on the x-axis and y-axis.

[0019] Another aspect of the present invention provides a method for photoacoustic fusion confocal microscopy with a large depth of field based on light field control. The above system and method include the following steps:

[0020] S1. The laser of the illumination beam power measurement component in the illumination system emits laser light, which is modulated by the position modulation optical component to generate a double-helix self-accelerating beam. The self-accelerating beam is irradiated to the object to be measured to excite the object to be measured.

[0021] S2, the superluminescent diode in the detection system emits incoherent long-wavelength light to detect the object to be detected;

[0022] S3. After being reflected by the object to be tested, the imaging system receives the reflected light and forms an image on the detector.

[0023] Furthermore, the specific steps of S1 are:

[0024] The laser of the illumination system emits a laser, which is shaped by the second lens, stray light is filtered out by the pinhole, and the illumination beam is modulated by the phase modulation optical component to generate a double-helix self-accelerating beam. The illumination beam power measurement component measures the power of the self-accelerating beam, and then the self-accelerating beam is shaped by the sixth lens, reflected by the dichroic mirror, and excited by the XY scanning galvanometer. The self-accelerating beam is shaped by the scanning lens and the tube lens, emitted to the reflector, and irradiated to the object to be tested through the objective lens to excite the object to be tested.

[0025] Furthermore, the illumination light beam is modulated by the phase modulation optical component to generate a double-helix self-accelerating light beam as follows:

[0026] The first lens expands the laser beam passing through the pinhole and outputs it to the half wave plate, which modulates the polarization state of the laser beam. After passing through the first polarization beam splitter prism PBS, it reflects S light and transmits P light. The reflected S light is modulated by the first quarter wave plate to generate linearly polarized light, which is modulated into a double-helix self-accelerating light beam by the optical module and then reflected back to the first quarter wave plate. It is modulated into P light by the first quarter wave plate, and after passing through the first polarization beam splitter prism PBS, the self-accelerating light beam is output to the second lens.

[0027] Furthermore, the illumination beam power measurement component measures the power of the self-accelerating beam specifically as follows:

[0028] The first lens expands the laser beam passing through the pinhole and outputs it to the half-wave plate, which modulates the polarization state of the laser beam. After passing through the first polarization beam splitter prism PBS, the S light is reflected and the P light is transmitted. The transmitted P light is incident on the photodetector to measure the power of the beam.

[0029] Furthermore, the specific steps of S2 are:

[0030] The superluminescent diode emits incoherent long-wavelength light, which is collimated by a reflective collimator, expanded by a beam expansion system composed of a third lens and a fourth lens, passes through a second polarization beam splitter prism PBS, modulated by a second quarter-wave plate, passes through a dichroic mirror, and is reflected and scanned by an XY scanning galvanometer. It is expanded by a scanning lens and a tube lens, reflected by a reflector, output to an objective lens, focused, and irradiated onto the object to be tested, thereby detecting the object to be tested.

[0031] Furthermore, the specific steps of S3 are:

[0032] The reflected signal of the object to be tested after detection is returned to the second quarter-wave plate through the objective lens, reflector, tube lens, scanning lens, XY scanning galvanometer, and dichroic mirror. After the reflected light is modulated by the second quarter-wave plate, it is output to the second polarization beam splitter prism PBS, reflected to the long-wave pass filter, stray light is filtered out, and output to the fifth lens, which is focused to the detector for imaging.

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] The present invention modulates the point spread function of the system at the illumination end, expands the axial size of its illumination point spread function, and enables it to have a large depth of field detection capability, aiming to solve the problem that high depth resolution and high resolution cannot be achieved simultaneously in chip defect detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is the overall system flow chart of the present invention;

[0036] Figure 2 is a schematic diagram of a self-accelerating beam phase mask of the present invention;

[0037] Figure 3 It is a schematic diagram of a phase modulation optical component for a large depth of field photoacoustic fusion confocal microscopy system of the present invention;

[0038] Figure 4 It is a schematic diagram of an illumination beam power measurement component of a large depth of field photoacoustic fusion confocal microscopy system of the present invention;

[0039] Figure 5 It is a schematic diagram of an illumination system of a large depth of field photoacoustic fusion confocal microscopy system of the present invention;

[0040] Figure 6 It is a schematic diagram of a detection system of a large depth of field photoacoustic fusion confocal microscopy system of the present invention;

[0041] Figure 7 It is a schematic diagram of an imaging system of a large depth of field photoacoustic fusion confocal microscopy system of the present invention;

[0042] Figure 8 It is a schematic diagram of a large depth of field photoacoustic fusion confocal microscopy system of the present invention;

[0043] In the figure, an illumination system 701, a detection system 702, an imaging system 703, a first lens 201, a half wave plate 202, a first polarization beam splitter PBS203, a second lens 204, a first quarter wave plate 205, an optical module 206, a photodetector 301, a laser 401, a second lens 402, a pinhole 403, a phase modulation optical component 404, an illumination beam power measurement component 405, a sixth lens 406, a dichroic mirror 407, an XY scanning galvanometer 408, a scanning lens 409, a tube lens 410, a reflector 411, an objective lens 412, a superluminescent diode 501, a reflective collimator 502, a third lens 503, a fourth lens 504, a photodetector 601, a fifth lens 602, a long wave pass filter 603, a second polarization beam splitter PBS604, and a second quarter wave plate 605. DETAILED DESCRIPTION

[0044] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0045] The present invention proposes a large depth of field photoacoustic fusion confocal microscopy system and method based on light field regulation, which modulates the point spread function of the system at the illumination end, expands the axial size of its illumination point spread function, and enables it to have a large depth of field detection capability, aiming to solve the problem that it is impossible to have both high depth resolution and high resolution at the same time in chip defect detection.

[0046] The system of the present invention includes an illumination system 701, a detection system 702 and an imaging system 703, wherein the illumination system 701 includes a phase modulation optical component 404 and an illumination beam power measurement component 405, wherein the phase modulation optical component 404 includes a first lens 201, a half wave plate 202, a first polarization beam splitter prism PBS203, a second lens 204, a first quarter wave plate 205 and an optical module 206, wherein the optical module 206 is used to modulate the illumination point spread function to generate a self-accelerating beam, wherein the self-accelerating beam is generated based on a cubic phase or an exponential phase or a transformed exponential phase; the illumination beam power measurement component 405 includes a first lens 201, a half wave plate 202, a first polarization beam splitter prism PBS203, a second lens 204 and a photodetector 301;

[0047] The illumination system 701 further includes a laser 401, a second lens 402, a pinhole 403, a sixth lens 406, a dichroic mirror 407, an XY scanning galvanometer 408, a scanning lens 409, a tube lens 410, a reflector 411 and an objective lens 412;

[0048] The detection system 702 includes a superluminescent diode 501, a reflective collimator 502, a third lens 503, a fourth lens 504, a second polarization beam splitter prism PBS604, a second quarter wave plate 605, a dichroic mirror 407, an XY scanning galvanometer 408, a scanning lens 409, a tube lens 410, a reflector 411 and an objective lens 412;

[0049] The imaging system 703 includes a photodetector 601, a fifth lens 602, a long-wave filter 603, a polarization beam splitter PBS 604, a second quarter-wave plate 605, a dichroic mirror 407, an XY scanning galvanometer 408, a scanning lens 409, a tube lens 410, a reflector 411 and an objective lens 412. The working process of the system is as follows: Figure 1 shown.

[0050] The assembly process of the system of the present invention is as follows:

[0051] Phase modulation optical components to create self-accelerating beam modulation;

[0052] The illumination point spread function of the photoacoustic fusion confocal microscopy system is modulated by the phase modulation optical component at the illumination end thereof to obtain a self-accelerating illumination point spread function with a large axial size;

[0053] Create a photodetector-based illumination beam power measurement module;

[0054] The detection point spread function of the photoacoustic fusion confocal microscopy system is modulated by the phase modulation optical component at the detection end to obtain a self-acceleration detection point spread function with a large axial size;

[0055] The phase modulation optical component is combined with the illumination beam power measurement module through a polarization beam splitter prism PBS.

[0056] Based on the above system, the present invention also proposes a large depth of field photoacoustic fusion confocal microscopy method, the method comprising the following steps:

[0057] S1, the laser 401 of the illumination beam power measurement component 405 in the illumination system 701 emits a laser, which is modulated by the position modulation optical component 404 to generate a double-helix self-accelerating beam, and the self-accelerating beam is irradiated to the object to be measured to excite the object to be measured;

[0058] S2, the superluminescent diode 501 in the detection system 702 emits incoherent long wavelength light to detect the object to be detected;

[0059] S3 . After being reflected by the object to be tested, the imaging system 703 receives the reflected light and forms an image on the detector 601 .

[0060] The phase modulation optical component 404 of the present invention includes various optical elements arranged in sequence along the light path transmission direction:

[0061] Lens 1, used to adjust the size of the illumination beam to match the aperture of the subsequent optical module;

[0062] Half-wave plate changes the phase delay of incident light and changes the polarization characteristics of light;

[0063] Polarization beam splitter (PBS), transmits P light and reflects S light;

[0064] A quarter wave plate, which works in conjunction with the half wave plate to change the polarization direction of light;

[0065] An optical module, used for performing self-accelerating beam phase modulation on the laser beam passing through the polarization beam splitter prism and the quarter-wave plate to generate an imaging beam with self-accelerating beam properties;

[0066] Lens 2 is used to adjust the size of the illumination beam to match the aperture of the subsequent optical module.

[0067] The illumination beam power measurement assembly 405 includes various optical elements arranged in sequence along the light path transmission direction:

[0068] Lens 1, used to adjust the size of the illumination beam to match the aperture of the subsequent optical module;

[0069] Half-wave plate changes the phase delay of incident light and changes the polarization characteristics of light;

[0070] Polarization beam splitter (PBS), transmits P light and reflects S light;

[0071] Photodetectors, such as photodiodes, are used to measure the power of the illumination beam;

[0072] Lens 2 is used to adjust the size of the illumination beam to match the aperture of the subsequent optical module.

[0073] The lighting system 701 includes the following components arranged in sequence along the light path transmission direction:

[0074] A laser for generating an illumination beam;

[0075] Pinhole, used to shield stray light;

[0076] Lens 1, used to adjust the size of the illumination beam to match the aperture of the subsequent optical module;

[0077] A modulation optical component, using the above-mentioned phase modulation optical component, is used to convert the illumination light beam into a self-accelerating light beam with a large depth of field;

[0078] A light intensity measurement optical component, used for measuring the power of the illumination light beam;

[0079] Lens 2, used to adjust the size of the illumination beam to match the aperture of the subsequent optical module;

[0080] A dichroic mirror, used for reflecting the illumination light beam;

[0081] XY scanning galvanometer, a two-dimensional scanning galvanometer, is used to change the propagation direction of the illumination beam for scanning imaging;

[0082] The scanning lens and the tube lens form a beam expansion system to make the illumination beam fill the aperture of the objective lens;

[0083] The tube lens, together with the scanning lens, forms a beam expansion system, which emits the illumination beam in parallel to the pupil plane of the objective lens, so that the illumination beam fills the aperture of the objective lens, and combines with the objective lens to correct the aberration of the objective lens;

[0084] Reflectors, which change the propagation direction of the illumination beam;

[0085] The objective lens is used to focus the illumination beam and output it, thereby changing the ultrasonic or reflection characteristics of the substance to be tested.

[0086] The detection system 702 includes the following components arranged in sequence along the optical transmission direction:

[0087] a superluminescent diode to generate an incoherent probe beam;

[0088] A reflective collimator to collimate the detection beam;

[0089] A beam expander module is used to adjust the size of the illumination beam to match the aperture of the subsequent optical module;

[0090] The polarization beam splitter (PBS) transmits the P light and reflects the S light; that is, it transmits the detection beam and reflects the imaging beam, i.e., the reflected beam;

[0091] A quarter wave plate changes the polarization properties of light;

[0092] A dichroic mirror, which is used together with the dichroic mirror in the illumination light path, transmits the detection beam and the imaging beam, and reflects the illumination beam;

[0093] An XY scanning galvanometer, which shares the same XY scanning galvanometer with the illumination beam, is used to change the propagation direction of the detection beam;

[0094] The scanning lens shares the same scanning lens with the illumination beam and forms a beam expansion system with the tube lens, so that the detection beam fills the aperture of the objective lens;

[0095] The tube lens shares the same tube lens with the illumination beam and forms a beam expansion system with the tube lens, so that the detection beam fills the aperture of the objective lens and is combined with the objective lens to correct the aberration of the objective lens;

[0096] A reflector, which shares the same reflector with the illumination beam and is used to change the transmission direction of the detection beam;

[0097] The objective lens is used to focus the detection beam and output it to detect the molecules to be tested after excitation.

[0098] The imaging system includes the following components arranged in sequence along the optical transmission direction:

[0099] A detector, used for receiving the reflected detection light beam and performing imaging;

[0100] a lens for focusing the reflected probe beam;

[0101] Long-wave pass filters transmit light with wavelengths longer than a specific cut-off wavelength, but block light with shorter wavelengths, filtering out stray light;

[0102] The polarization beam splitter (PBS) shares the same PBS with the above detection system, transmits the P light and reflects the S light; that is, transmits the detection beam and reflects the imaging beam;

[0103] A quarter wave plate changes the polarization properties of light;

[0104] A dichroic mirror, which is shared with the dichroic mirrors of the illumination light path and the detection light path, transmits the detection light beam and the imaging light beam, and reflects the illumination light beam;

[0105] An XY scanning galvanometer is shared with the scanning galvanometers of the illumination light path and the detection light path, and the illumination light beam and the detection light beam share the same XY scanning galvanometer, and is used to change the propagation direction of the detection light beam;

[0106] The scanning lens is shared with the scanning lenses of the illumination light path and the detection light path, and forms a beam expansion system with the tube lens to change the size of the imaging beam;

[0107] The tube lens is shared with the tube lenses of the illumination light path and the detection light path, and together with the tube lens, it forms a beam expansion system, changes the size of the imaging light beam, and is combined with the objective lens to correct the aberration of the objective lens;

[0108] A reflector, shared with the tube lens of the illumination light path and the detection light path, for changing the transmission direction of the imaging light beam;

[0109] Objective lens, focusing imaging.

[0110] The present invention creates an optical phase modulation optical component based on a self-accelerating light beam, and after the phase modulation optical component modulates the light beam of the illumination light path, a self-accelerating light beam is generated. An illumination method for a large depth of field photoacoustic fusion confocal microscopy system based on self-accelerating light beam modulation is proposed, and a modulation method for a self-accelerating light beam using a spectroscopic system based on a polarization spectroscopic prism and a method for measuring the optical power of a photodiode are proposed; a detection method based on a superluminescent diode is proposed; a spectroscopic system based on a polarization spectroscopic prism is proposed for a detection method of a superluminescent diode and an imaging method of a light detector are proposed; a method for combining an excitation light beam, a detection light beam and an imaging light beam based on a dichroic mirror is proposed; a system for conjugating an excitation light beam, a detection light beam and an imaging light beam with respect to a scanning galvanometer and an objective lens is proposed; a spectroscopic system combining a quarter wave plate, a polarization spectroscopic prism and a half wave plate is proposed; and the axial detection range of the system can be adjusted by adjusting the design parameters. The invention improves the axial detection range of the optical microscopy system without the need for axial scanning, and solves the problem of large depth of field and high signal-to-noise ratio detection in the detection technology of biological macromolecules in living cells.

[0111] The design principle of the optical module (206) is as follows:

[0112] P(x, y) = α((x-β) 3 -(y-β) 3 ) (1)

[0113] The self-accelerating beam of the optical assembly can also be achieved by the following index phase:

[0114] P(x, y) = αx·exp(βx 2 )+αy·exp(βy 2 ) (2)

[0115] The self-accelerating beam of the optical assembly can also be achieved by transforming the following index phase:

[0116] P(x, y) = α(xy) exp(β(xy) 2 )+α(x+y)·exp(β(x+y) 2 ) (3)

[0118] P(x, y) = α(xy) exp(β(xy) 2 )-α(x+y)·exp(β(x+y) 2 ) (4)

[0120] The self-accelerating beam of the optical component can also be realized by the caustic method, as well as the self-accelerating beam with transverse self-acceleration properties designed by other methods;

[0121] In the above formula, α and β are design parameters, which can adjust the axial size and transverse self-acceleration speed of the self-accelerating beam. Figure 2 shown.

[0122] A self-accelerating point spread function optical system is a system in which a specially designed optical module is added to the Fourier plane of a standard imaging system. This optical module makes its transmittance function take the form of a self-accelerating point spread function in the Fourier-transformed focal region. The phase modulation optical component created above has this characteristic.

[0123] Furthermore, according to the optical transmission properties, the optical component has two implementation methods. One is through transmission modulation, such as optical modulation components such as phase plate, transmission digital micromirror device DMD, transmission spatial light modulator, etc.; the other is through reflection modulation, such as reflective spatial light modulator.

[0124] Figure 3The schematic diagram of the phase modulation optical component of the present invention is shown. The phase modulation optical component includes a first lens 201, a half wave plate 202, a polarization beam splitter prism PBS203, a second lens 204, a quarter wave plate 205 and an optical module 206 which are sequentially arranged along the transmission direction of the optical path. Among them, the phase modulation module 206 has the above-mentioned self-accelerating beam properties, is designed based on the above-mentioned method, and has the functions described in the above-mentioned embodiment 1, which will not be repeated here. In this system, the first lens 201 expands the laser beam emitted by the laser and outputs it to the half wave plate 202, and the half wave plate 202 modulates the polarization state of the laser beam, and the output is suitable for the output of the polarization beam splitter prism PBS, reflects S light, and transmits P light. The S light reflected by the PBS is modulated by the quarter wave plate 205 into linearly polarized light suitable for modulation by 206, and after being modulated by 206 into a self-accelerating beam, it is reflected back to the quarter wave plate 205, modulated into P light by the quarter wave plate 205, and output to the lens 204 through the polarization beam splitter prism PBS.

[0125] Figure 4 The schematic diagram of the illumination beam power measurement component of the present invention is shown. The illumination beam power measurement component mainly includes a first lens 201, a half wave plate 202, a polarization beam splitter prism PBS203, a second lens 204 and a photodetector 301 which are arranged in sequence along the optical path transmission direction. In the system, the first lens 201 expands the laser beam emitted by the laser and outputs it to the half wave plate 202. The half wave plate 202 modulates the polarization state of the laser beam, and the output is suitable for the output of the polarization beam splitter prism PBS, which reflects the S light and transmits the P light. The P light transmitted through the PBS is output to the photodetector 301, and the power of the beam is measured by the photodetector.

[0126] Figure 5 A schematic diagram of a lighting system of the present invention is shown.

[0127] The present invention adopts the method of laser output illumination, such as Figure 5 As shown, the illumination system of the large depth of field photoacoustic fusion confocal microscopy system includes a laser 401, a lens 402, a pinhole 403, a phase modulation optical component 404, an illumination beam power measurement component 405, a lens 406, a dichroic mirror 407, an XY scanning galvanometer 408, a scanning lens 409, a tube lens 410, a reflector 411, and an objective lens 412, which are arranged in sequence along the transmission direction of the optical path.

[0128] In the illumination system, laser light is emitted by a laser 401, rectified by a lens 402, stray light is filtered out by a pinhole 403, the illumination light beam is modulated by a phase modulation optical component 404 to generate a self-accelerating light beam, the power of which is measured by an illumination light beam power measurement component 405, rectified by a lens 406, reflected by a dichroic mirror 407, scanned by an XY scanning galvanometer 408 to excite a sample, shaped by a scanning lens 409 and a tube lens 410, emitted to a reflector 411, and finally focused by an objective lens 412 to irradiate an object to be tested, thereby exciting the object to be tested.

[0129] Figure 6 Schematic diagram of the detection system of the present invention is shown. Figure 6 As shown, the detection system of the large depth of field photoacoustic fusion confocal microscopy system includes a superluminescent diode 501, a reflective collimator 502, a lens 503, a lens 504, a polarization beam splitter prism (PBS) 604, a quarter wave plate 605, a dichroic mirror 407, an XY scanning galvanometer 408, a scanning lens 409, a tube lens 410, a reflector 411, and an objective lens 412, which are arranged in sequence along the transmission direction of the light path.

[0130] In the detection system, a superluminescent diode 501 of the detection system emits a long wavelength incoherent light, which is collimated by a reflective collimator 502, and then expanded by a beam expansion system composed of a lens 503 and a lens 504. The light passes through a polarization beam splitter (PBS) 604, is modulated by a quarter-wave plate 605, passes through a dichroic mirror 407, is reflected and scanned by an XY scanning galvanometer 408, is expanded by a scanning lens 409 and a tube lens 410, is reflected by a reflector 411, and is output to an objective lens 412. Finally, the light is focused and irradiated to an object to be detected by the objective lens 412, and then detected.

[0131] Figure 7 The schematic diagram of the imaging system of the present invention is shown. In the imaging system, the incoherent long-wavelength light emitted by the superluminescent diode 501 of the detection system is finally focused by the objective lens 412 to irradiate the object to be tested, and the reflected signal of the object to be tested is detected, and then the reflected light is returned to the quarter-wave plate 605 through the objective lens 412, the reflector 411, the tube lens 410, the scanning lens 409, the XY scanning galvanometer 408, and the dichroic mirror 407. After the reflected light is modulated by the quarter-wave plate 605, it is output to the polarization beam splitter prism (PBS) 604 and reflected to the long-wave filter 603. The stray light is filtered out, output to the lens 602, and focused to the detector 601 through the lens 602 for imaging.

[0132] Figure 8 The overall structure of the system of the present invention is shown. The large depth of field photoacoustic fusion confocal microscopy system is composed of an illumination system 701, a detection system 702 and an imaging system 703 which are sequentially arranged along the transmission direction of the light path.

[0133] In the imaging system, laser 401 emits laser light, which is modulated by phase modulation optical component 404 to generate a double helix light beam, which is then excited by illumination system 701 to change the properties of the object to be tested. Then, incoherent long-wavelength light is emitted by detection system 702 to detect the object to be tested. After being reflected by the object to be tested, the reflected light is received by imaging system 703 to perform imaging.

[0134] The above-mentioned large-depth-of-field photoacoustic fusion confocal microscopy method performs large-depth-of-field photoacoustic fusion imaging through the optical components provided by the present invention, and utilizes a self-accelerating light beam with a large axial detection range to achieve both high depth resolution and high resolution non-destructive testing.

[0135] The self-accelerating beam of the optical component of the present invention can also be realized by the caustic method, as well as the self-accelerating beam with lateral self-acceleration properties designed by other methods. The optical module is a phase plate, a spatial light modulator or a DMD made by micro-machining technology.

[0136] The preferred specific embodiments of the present invention are described in detail above. It should be understood that a person skilled in the art can make many modifications and changes based on the concept of the present invention without creative work. Therefore, any technical solution that can be obtained by a person skilled in the art through logical analysis, reasoning or limited experiments based on the concept of the present invention on the basis of the prior art should be within the scope of protection determined by the claims.

Claims

1. A photoacoustic fusion confocal microscopy system with large depth of field based on light field control, characterized in that: The system comprises an illumination system (701), a detection system (702) and an imaging system (703), wherein the illumination system (701) comprises a phase modulation optical component (404) and an illumination beam power measurement component (405), wherein the phase modulation optical component (404) comprises a first lens (201), a half wave plate (202), a first polarization beam splitter prism PBS (203), a second lens (204), a first quarter wave plate (205) and an optical module (206), wherein the optical module (206) is used to modulate the illumination point spread function to generate a self-accelerating beam, wherein the self-accelerating beam is generated based on a cubic phase or an exponential phase or a transformed exponential phase; and the illumination beam power measurement component (405) comprises a first lens (201), a half wave plate (202), a first polarization beam splitter prism PBS (203), a second lens (204) and a photodetector (301); The illumination system (701) further comprises a laser (401), a second lens (402), a pinhole (403), a sixth lens (406), a dichroic mirror (407), an XY scanning galvanometer (408), a scanning lens (409), a tube lens (410), a reflector (411) and an objective lens (412); The detection system (702) includes a superluminescent diode (501), a reflective collimator (502), a third lens (503), a fourth lens (504), a second polarization beam splitter prism PBS (604), a second quarter wave plate (605), a dichroic mirror (407), an XY scanning galvanometer (408), a scanning lens (409), a tube lens (410), a reflector (411) and an objective lens (412); The imaging system (703) comprises a photodetector (601), a fifth lens (602), a long-wave pass filter (603), a polarization beam splitter prism PBS (604), a second quarter-wave plate (605), a dichroic mirror (407), an XY scanning galvanometer (408), a scanning lens (409), a tube lens (410), a reflector (411) and an objective lens (412).

2. According to claim 1, a large depth of field photoacoustic fusion confocal microscopy system based on light field control is characterized in that: The cubic phase is: P(x,y)=α((x-β) 3 -(y-β) 3 ) Among them, α and β are design parameters, and x and y represent the variables propagated on the x-axis and y-axis.

3. According to claim 1, a large depth of field photoacoustic fusion confocal microscopy system based on light field control is characterized in that: The exponential phase is: P(x,y)=0x·exp(βx 2 )+y·exp(βy 2 ) Among them, α and β are design parameters, and x and y represent the variables propagated on the x-axis and y-axis.

4. The large depth of field photoacoustic fusion confocal microscopy system based on light field control according to claim 1, characterized in that: The transformed exponential phase is: P(x,y)=α(x-y)·exp(β(x-y) 2 )+α(x+y)·exp(β(x+y) 2 ) P(x,y)=α(x-y)·exp(β(x-y) 2 )-α(x+y)·exp(β(x+y) 2 ) Among them, α and β are design parameters, and x and y represent the variables propagated on the x-axis and y-axis.

5. A large depth of field photoacoustic fusion confocal microscopy method based on light field regulation, characterized in that: Based on the system according to any one of claims 1 to 9, the method comprises the following steps: S1, the laser (401) of the illumination beam power measurement component (405) in the illumination system (701) emits laser light, which is modulated by the position modulation optical component (404) to generate a double-helix self-accelerating beam, and the self-accelerating beam is irradiated to the object to be measured to excite the object to be measured; S2, the superluminescent diode (501) in the detection system (702) emits incoherent long-wavelength light to detect the object to be detected; S3. After being reflected by the object to be tested, the imaging system (703) receives the reflected light and forms an image on the detector (601).

6. The method of photoacoustic fusion confocal microscopy with large depth of field based on light field control according to claim 5, characterized in that: The specific steps of S1 are: The laser (401) of the illumination system (701) emits laser light, which is shaped by the second lens (402), stray light is filtered out by the pinhole (403), the illumination light beam is modulated by the phase modulation optical component (404), a double-helix self-accelerating light beam is generated, the illumination light beam power measurement component (405) measures the power of the self-accelerating light beam, and then the self-accelerating light beam is shaped by the sixth lens (406), reflected by the dichroic mirror (407), and excited by the XY scanning galvanometer (408), and the self-accelerating light beam is shaped by the scanning lens (409) and the tube lens (410), and emitted to the reflector (411), and irradiated to the object to be measured through the objective lens (412), thereby exciting the object to be measured.

7. The method of photoacoustic fusion confocal microscopy with large depth of field based on light field control according to claim 6, characterized in that: The illumination light beam is modulated by the phase modulation optical component (404) to generate a double helix self-accelerating light beam as follows: The first lens (201) expands the laser beam passing through the pinhole (403) and outputs it to the half wave plate (202). The half wave plate (202) modulates the polarization state of the laser beam. After passing through the first polarization beam splitter prism PBS (203), the laser beam reflects S light and transmits P light. The reflected S light is modulated by the first quarter wave plate (205) to generate linearly polarized light, which is modulated into a double-helix self-accelerating light beam by the optical module (206) and then reflected back to the first quarter wave plate (205). After being modulated into P light by the first quarter wave plate (205), the self-accelerating light beam is transmitted through the first polarization beam splitter prism PBS (203) and output to the second lens (204).

8. The method of photoacoustic fusion confocal microscopy with large depth of field based on light field control according to claim 6, characterized in that: The illumination beam power measurement component (405) measures the power of the self-accelerating beam specifically as follows: The first lens (201) expands the laser beam passing through the pinhole (403) and outputs it to the half wave plate (202). The half wave plate (202) modulates the polarization state of the laser beam. After passing through the first polarization beam splitter prism PBS (203), the S light is reflected and the P light is transmitted. The transmitted P light is incident on the photoelectric detector (301) to measure the power of the beam.

9. The method of photoacoustic fusion confocal microscopy with large depth of field based on light field control according to claim 5, characterized in that: The specific steps of S2 are: A superluminescent diode (501) emits incoherent long-wavelength light, which is collimated by a reflective collimator (502), expanded by a beam expansion system composed of a third lens (503) and a fourth lens (504), passes through a second polarization beam splitter prism PBS (604), is modulated by a second quarter-wave plate (605), passes through a dichroic mirror (407), is reflected and scanned by an XY scanning galvanometer (408), expanded by a scanning lens (409) and a tube lens (410), reflected by a reflector (411), and output to an objective lens (412) to focus and illuminate an object to be tested, thereby detecting the object to be tested.

10. The method of photoacoustic fusion confocal microscopy with large depth of field based on light field control according to claim 5, characterized in that: The specific steps of S3 are: After detection, the reflected signal of the object to be tested is returned to the second quarter wave plate (605) via the objective lens (412), the reflector (411), the tube lens (410), the scanning lens (409), the XY scanning galvanometer (408), and the dichroic mirror (407). After the reflected light is modulated by the second quarter wave plate (605), it is output to the second polarization beam splitter prism PBS (604), reflected to the long wave pass filter (603), stray light is filtered out, and output to the fifth lens (602), and is focused to the detector (601) for imaging via the fifth lens (602).

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