Three-dimensional tomography method, device, equipment and system

Abstract

The invention provides a three-dimensional tomography method, device, equipment and system, and can improve the imaging speed of three-dimensional tomography, and the method comprises the steps: reconstructing emergent wave functions, corresponding to different emergent wavelengths, of a target object according to the actual diffraction coherence intensity of the target object, obtaining emergent wave reconstruction functions, corresponding to the different emergent wavelengths, of the target object, wherein the emergent wave reconstruction functions comprise amplitude information and phase information; wherein the actual diffraction coherence intensity is the actual diffraction coherence total intensity detected by the target object under the simultaneous action of the light beams with the different emergent wavelengths, or comprises the actual diffraction coherence intensity detected by the target object under the action of the light beams with the different emergent wavelengths; and obtaining imaging information on different layers of the target object according to the emergent wave reconstruction function of the target object corresponding to the different emergent wavelengths. According to the invention, the imaging speed of three-dimensional tomography can be improved.

Description

Technical Field

[0001] The present application relates to the field of optical imaging, and in particular to a three-dimensional tomography method, device, equipment and system. Background Art

[0002] Three-dimensional tomography is an efficient method that can obtain layered information of tiny samples and achieve three-dimensional measurement of their internal structure. This non-invasive, high-resolution imaging technology has wide application value in the field of science and technology, and is suitable for non-destructive testing and three-dimensional imaging in biology, medicine, engineering and other fields. A common three-dimensional tomography technology is optical coherence tomography (OCT).

[0003] There are many types of OCT technologies. One existing time-domain OCT imaging system uses single-wavelength low-coherence light as the light source. By moving the reference mirror along the optical axis, the optical path difference between the sample arm and the reference arm is adjusted to achieve scanning and tomographic imaging of the sample in the depth direction. If the combined light beam is scanned in the layering direction of the sample, the optical section image information of the sample at a certain depth position can be recorded. Then, the combined light beam performs a two-dimensional scan of the sample perpendicular to the depth direction, which can achieve a three-dimensional scan of the sample.

[0004] However, the imaging speed and imaging resolution of the sample in the time-domain OCT technology are contradictory. While ensuring the imaging resolution, the imaging speed is limited by the speed of moving the reference mirror along the optical axis and the scanning speed in the two-dimensional scanning. The scanning speed limits the application of the three-dimensional tomography technology. Summary of the invention

[0005] The present application provides a three-dimensional tomography method, device, equipment and system, which can have both high resolution and high imaging speed.

[0006] In a first aspect, the present application provides a three-dimensional tomography method, comprising:

[0007] Reconstructing the exit wave functions of the target object corresponding to different exit wavelengths respectively according to the actual diffraction coherence intensity of the target object, and obtaining the exit wave reconstruction functions of the target object corresponding to the different exit wavelengths respectively, wherein the exit wave reconstruction functions include amplitude information and phase information; wherein the actual diffraction coherence intensity is the actual diffraction coherence total intensity detected by the target object under the simultaneous action of the light beams of the different exit wavelengths, or includes the actual diffraction coherence intensity detected by the target object under the action of the light beams of the different exit wavelengths respectively;

[0008] Imaging information on different layers of the target object is obtained according to the outgoing wave reconstruction functions corresponding to the different outgoing wavelengths of the target object.

[0009] Optionally, acquiring imaging information on different layers of the target object according to the output wave reconstruction functions corresponding to the different output wavelengths of the target object respectively includes:

[0010] Transmitting the outgoing wave reconstruction functions of the target object corresponding to the different outgoing wavelengths to the layers at different depths of the target object to obtain the complex amplitude information of the target object corresponding to the different outgoing wavelengths at each layer in the layers at different depths;

[0011] The complex amplitude information of the target object corresponding to different wavelengths on each layer is superimposed to obtain imaging information on the layer.

[0012] Optionally, the step of returning the outgoing wave reconstruction functions of the target object corresponding to the different outgoing wavelengths to layers at different depths of the target object comprises:

[0013] For each of the layers at different depths, the diffraction propagation operator is used to calculate the complex amplitude information of the outgoing wave reconstruction function of the target object corresponding to the different outgoing wavelengths on the layer.

[0014] Optionally, the number of the different emission wavelengths is N, and the acquiring imaging information on different layers of the target object according to the emission wave reconstruction functions corresponding to the different emission wavelengths of the target object respectively includes:

[0015] The outgoing wave reconstruction functions of the target object corresponding to the different outgoing wavelengths are refocused on N layers at different depths of the target object to obtain complex amplitude information of each layer in the N layers at different depths.

[0016] Optionally, the actual diffraction coherence intensity is obtained according to a diffraction pattern detected when the target object is acted upon simultaneously or separately by the light beams of different emission wavelengths;

[0017] The method further comprises:

[0018] According to the diffraction pattern, constructing a one-dimensional spectrum data array for each pixel point in the diffraction pattern according to the emission wavelength;

[0019] An inverse Fourier transform is performed on the one-dimensional spectrum data array of each pixel point to obtain information of different depths of the target object at the pixel point.

[0020] Optionally, reconstructing the output wave functions of the target object under different output wavelengths according to the actual diffraction coherence intensity of the target object to obtain the reconstructed output wave functions of the target object corresponding to the different output wavelengths respectively includes:

[0021] Acquire an initial function of an outgoing wave of the target object at a sample surface, wherein the initial function of the outgoing wave at the sample surface is an initial function of an outgoing wave of the target object at the sample surface under the simultaneous action of different outgoing wavelengths;

[0022] Taking the initial function of the outgoing wave at the sample surface as input, performing at least one iteration to obtain an updated function of the outgoing wave at the sample surface, wherein in each iteration: modulating and demodulating the outgoing wave at the sample surface according to the modulator function, and using the actual diffraction coherence intensity to perform amplitude constraint on the modulated outgoing wave between the modulation and the demodulation, wherein the actual diffraction coherence intensity is the actual diffraction coherence total intensity detected by the target object under the simultaneous action of the different outgoing wavelengths;

[0023] The outgoing wave reconstruction functions of the target object corresponding to the different outgoing wavelengths are separated from the outgoing wave update function at the sample surface.

[0024] Optionally, reconstructing the output wave functions of the target object under different output wavelengths according to the actual diffraction coherence intensity of the target object to obtain the reconstructed output wave functions of the target object corresponding to the different output wavelengths respectively includes:

[0025] Acquire a plurality of initial functions of outgoing waves of the target object at the sample surface, wherein the plurality of initial functions of outgoing waves at the sample surface are initial functions of outgoing waves of the target object at the sample surface under the action of different outgoing wavelengths respectively;

[0026] The following steps are performed for each outgoing wave initial function at the sample surface corresponding to each wavelength beam:

[0027] Taking the initial function of the outgoing wave as input, performing at least one iteration to obtain an updated function of the outgoing wave at the sample surface;

[0028] Separating an outgoing wave reconstruction function of the target object corresponding to the wavelength light beam from the outgoing wave update function at the sample surface;

[0029] Wherein, in each iteration: the outgoing wave of the sample surface is modulated and demodulated according to the modulator function, and the actual diffraction coherence intensity is used to constrain the amplitude of the modulated outgoing wave between the modulation and demodulation; the actual diffraction coherence intensity is the actual diffraction coherence intensity detected by the target object under the action of the wavelength light beam.

[0030] Optionally, the method further comprises:

[0031] The target object is irradiated with light beams of different emission wavelengths simultaneously or sequentially to obtain emission waves;

[0032] Modulating the output wave using a modulator to obtain a modulated output wave;

[0033] The modulated outgoing wave is detected by a detector to obtain the actual diffraction coherence intensity of the target object.

[0034] In a second aspect, the present application provides a three-dimensional tomography device, comprising:

[0035] A reconstruction module, used to reconstruct the exit wave functions of the target object corresponding to different exit wavelengths according to the actual diffraction coherence intensity of the target object, so as to obtain the exit wave reconstruction functions of the target object corresponding to the different exit wavelengths, wherein the exit wave reconstruction functions include amplitude information and phase information; wherein the actual diffraction coherence intensity is the actual diffraction coherence total intensity detected by the target object under the simultaneous action of the light beams of the different exit wavelengths, or includes the actual diffraction coherence intensity detected by the target object under the action of the light beams of the different exit wavelengths;

[0036] The imaging module is used to obtain imaging information of the target object in other dimensions according to the outgoing wave reconstruction functions corresponding to the different outgoing wavelengths of the target object.

[0037] In a third aspect, the present application provides a three-dimensional tomography device, comprising:

[0038] Processor; and

[0039] A memory having executable codes stored thereon, which, when executed by the processor, causes the processor to execute the method according to any one of claims 1 to 7.

[0040] In a fourth aspect, the present application provides a three-dimensional imaging system, comprising:

[0041] An illumination light source, used for emitting light beams of different emission wavelengths simultaneously or sequentially to illuminate a target object to obtain an emission wave;

[0042] A modulator, used for modulating the outgoing wave to obtain a modulated outgoing wave;

[0043] A detector, used to detect the modulated outgoing wave to obtain the actual diffraction coherence intensity of the target object;

[0044] The above-mentioned three-dimensional tomography device is used to obtain three-dimensional imaging information of the target object according to the actual diffraction coherence intensity of the target object.

[0045] In the embodiment of the present application, the output wave functions of the target object corresponding to different output wavelengths are reconstructed according to the actual diffraction coherence intensity of the target object. The actual diffraction coherence intensity can be obtained by single-exposure imaging or fewer exposure imaging without lateral scanning, which can achieve rapid full-field imaging of the target object in the two-dimensional direction. In addition, the reconstructed corresponding output wave functions of different output wavelengths can use the Wiener-Khinchin theorem to image different layers of the target object. Compared with the prior art, the present application can improve the imaging speed while ensuring the imaging resolution. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 is a schematic diagram of an embodiment of the three-dimensional tomography method of the present application;

[0047] Figure 2a This is a schematic diagram of the optical path principle of multi-wavelength coherent modulation imaging provided by an embodiment of the present application;

[0048] Figure 2b is a schematic diagram of an embodiment of a method for obtaining actual diffraction coherence intensity of the present application;

[0049] Figure 3 It is a schematic diagram of the mode decomposition principle of multi-wavelength coherent diffraction imaging provided by an embodiment of the present application;

[0050] Figure 4 It is a schematic diagram of an embodiment of a method of reconstructing the output wave functions of the target object corresponding to different output wavelengths according to the actual diffraction coherence intensity of the target object according to the present application;

[0051] Figure 5 is a schematic diagram of an embodiment of an iteration in an iterative algorithm in a three-dimensional tomography method of the present application;

[0052] Figure 6 is a schematic diagram of an embodiment of a three-dimensional tomography device of the present application;

[0053] Figure 7 is a schematic diagram of an embodiment of a three-dimensional tomography device of the present application;

[0054] Figure 8 is a schematic diagram of an embodiment of a measurement system of the present application. DETAILED DESCRIPTION

[0055] The embodiments of the present application will be described in more detail below with reference to the accompanying drawings. Although the embodiments of the present application are shown in the accompanying drawings, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided to make the present application more thorough and complete, and to fully convey the scope of the present application to those skilled in the art.

[0056] The terms used in this application are for the purpose of describing specific embodiments only and are not intended to limit this application. The singular forms of "a", "said" and "the" used in this application and the appended claims are also intended to include plural forms unless the context clearly indicates other meanings. It should also be understood that the term "and / or" used herein refers to and includes any or all possible combinations of one or more associated listed items.

[0057] It should be understood that although the terms "first", "second", "third", etc. may be used in this application to describe various information, this information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of this application, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0058] like Figure 1 As shown, Figure 1 Schematic diagram of an embodiment of the three-dimensional tomography method of the present application. The three-dimensional tomography method comprises:

[0059] Step S101 , reconstructing the output wave functions of the target object corresponding to different output wavelengths according to the actual diffraction coherence intensity of the target object, and obtaining the output wave reconstruction functions of the target object corresponding to the different output wavelengths.

[0060] The method for obtaining the reconstruction function of the output wave of the target object in the example of the present application can adopt a coherent modulation imaging algorithm, and use the actual diffraction coherence intensity of the target object to reconstruct the output wave functions of the target object corresponding to different output wavelengths. The actual diffraction coherence intensity can be obtained by the diffraction pattern received by the detector in the single exposure imaging or multiple exposure imaging of the target object. Different from the existing coherent modulation imaging algorithm, the existing coherent modulation imaging is aimed at a single light source, and the output wave function of the target object is reconstructed according to the actual diffraction coherence intensity obtained by the detector from the diffraction pattern formed by the target object in a single exposure under the irradiation of the single light source, and the reconstructed output wave function is also unique.

[0061] In some examples of the coherent modulation imaging algorithm adopted in the present application, the output wave function of the target object is reconstructed according to the actual diffraction coherence intensity obtained by the detector from the diffraction pattern formed when the target object is exposed to the light source of different wavelengths (for example, a single exposure). That is, the actual diffraction coherence intensity is the actual diffraction coherence total intensity detected by the target object under the simultaneous action of the light beams of different output wavelengths. In this example, the incoherence of light sources of different wavelengths is utilized. Through a single exposure, the diffraction pattern received by the detector is a superposition of the output wave function intensities corresponding to the composite wavelength. In the reconstruction process, the diffraction pattern and the known information of different wavelengths are used as constraints, so that the output wave functions corresponding to all wavelengths can be solved at the same time, and the illumination function can also be separated.

[0062] Alternatively, in some examples, the coherent modulation imaging algorithm used in the present application may also be to illuminate the target object separately using light beams of different wavelengths. The actual diffraction coherence intensity includes the actual diffraction coherence intensity detected by the target object under the action of the light beams of different exit wavelengths. In this example, the exit wave functions of the target object corresponding to each wavelength are reconstructed respectively according to the actual diffraction coherence intensity corresponding to each wavelength obtained by the detector from the diffraction pattern formed by the target object exposed to the light beams of different wavelengths (e.g., single exposure).

[0063] Among them, the light beams with different output wavelengths can be emitted by different light sources, or can also be emitted by the same light source. For example, the output light of the same wide-spectrum light source can be emitted in sequence through different filters to obtain narrow-spectrum light beams with different output wavelengths, or it can be a wide-spectrum light beam emitted by the same wide-spectrum light source.

[0064] Step S102 : acquiring three-dimensional imaging information of the target object according to the outgoing wave reconstruction functions corresponding to the different outgoing wavelengths of the target object.

[0065] Reconstructing the outgoing wave functions of the target object corresponding to different outgoing wavelengths according to the actual diffraction coherence intensity of the target object still cannot obtain intuitive three-dimensional information about the target object. According to the Wiener-Khinchin theorem, the Fourier transform of the spectrum is the autocorrelation function of the light source. Therefore, it is possible to use the outgoing wave reconstruction function corresponding to different outgoing wavelengths to obtain imaging information of the target object in other dimensions.

[0066] There are many methods for obtaining three-dimensional imaging of a target object using the reconstruction functions of the outgoing waves corresponding to different outgoing wavelengths. In one example, the reconstruction functions of the outgoing waves of the target object corresponding to different outgoing wavelengths are respectively transmitted back to the layers at different depths of the target object to obtain the complex amplitude information of the target object corresponding to the different outgoing wavelengths at each layer in the layers at different depths; the complex amplitude information of the target object corresponding to different wavelengths at each layer is superimposed to obtain the imaging information on the layer.

[0067] There are many ways to layer. For example, automatic layering can be achieved using an autofocus algorithm. Specifically, the output wave reconstruction function obtained in step S101 is layered axially to obtain the absorption and phase delay information of the target object at different depths. The following formula is used to express it:

[0068]

[0069] Where layer(k) represents the complex amplitude information of the object wave at the kth layer of the target object; Slice{·} represents the layering operator. It represents the reconstruction function of the outgoing waves corresponding to N different outgoing wavelengths of the target object.

[0070] The positions of different layers of the target object are determined by the axial resolution and the maximum imaging depth. The spacing between layers and the number of layers can be determined as a multiple of the axial resolution within the maximum imaging depth.

[0071] Among them, the axial resolution Δz is expressed by the following formula:

[0072]

[0073] Among them, Δλ is the wavelength half-width of the wavelength range occupied by different emission wavelengths, and λ 0 is the central wavelength, n s is the refractive index of the target object.

[0074] Among them, the maximum imaging depth Z max The following formula represents:

[0075]

[0076] Wherein, N is the number of different emission wavelengths.

[0077] Among them, for each layer in the layer of different depths, when the outgoing wave reconstruction functions of the target object corresponding to the different outgoing wavelengths are transmitted back to the layer of the target object, the diffraction propagation operator can be used to calculate the complex amplitude information of the outgoing wave reconstruction functions of the target object corresponding to the different outgoing wavelengths and transmitted back to the layer. Optionally, the diffraction propagation operator can be an angular spectrum propagation operator. Through the angular spectrum algorithm, the complex amplitude information can be propagated forward or backward to any depth. In the prior art, the outgoing wave function reconstructed by a single wavelength cannot separate the internal information of different depths through the focusing algorithm of different depths. In this example, the complex amplitudes of different wavelengths are propagated to a certain depth to obtain new light field information. Superimposing all these light fields will form a coherent gate effect. The scattered light outside the depth of the specified layer is superimposed as a constant background, and there is no interference, that is, the scattered light at other depths can be shielded.

[0078] In a specific example, the tomographic imaging information of different layers of the target object is expressed as follows:

[0079]

[0080] in, Represents the complex amplitude information superposition operator corresponding to different wavelengths; AS -1 {·} represents the inverse angular spectrum propagation operator. layer(k) represents the complex amplitude information of the object wave at the kth layer of the target object; It represents the reconstruction function of the outgoing waves corresponding to N different outgoing wavelengths of the target object.

[0081] In some other examples of the method of realizing three-dimensional imaging of a target object by using an output wave reconstruction function corresponding to different output wavelengths, the number of different output wavelengths is N, and the output wave reconstruction functions of the target object corresponding to the different output wavelengths are refocused on N layers of different depths of the target object to obtain the complex amplitude information of each layer in the N layers of different depths. Due to the difference in the absorption and refractive index of the target object for light of different wavelengths, as well as the penetration depth, there may be a small offset in the focusing distance for the output wave of a single wavelength during the reconstruction process. In this example, since the output wave reconstruction functions of the target object corresponding to different wavelengths are all independent of each other, the focusing and reconstruction process of the output wave function of each wavelength can also be directly performed through diffraction propagation to realize the focusing of the output wave function of the target object at different distances, that is, the imaging information of the target object at different focusing levels.

[0082] Optionally, the angular spectrum diffraction algorithm can be used to refocus the outgoing wave reconstruction functions of the target object corresponding to the different outgoing wavelengths on N layers of different depths of the target object. Angular spectrum propagation is a type of diffraction propagation, which is suitable for wavefront propagation calculation with a small divergence angle and a short propagation distance (such as the propagation of interlayer wave fields in thick samples or small sample thickness), or for situations where different elements in the target object respond significantly to light wavelengths.

[0083] In a specific example, the function for reconstructing the outgoing waves of N different wavelengths corresponding to the target object is Combining the different penetration depths of different wavelengths, the angular spectrum propagation operator is used for refocusing to achieve sample tomography. The tomography information of different layers of the target object is expressed as follows:

[0084]

[0085] Where AS{·} represents the angular spectrum propagation operator; subscript z 1 , z 2 , ..., z n are the depths of N different layers of the target object.

[0086] Compared with the time-domain OCT imaging system in the prior art, which needs to repeatedly move the reference mirror along the optical axis to realize the scanning and tomographic imaging of the sample in the depth direction, resulting in the imaging speed of the OCT technology being limited by the scanning speed of the mechanical scanning device; in the embodiment of the present application, the output wave functions of the target object corresponding to different output wavelengths are reconstructed according to the actual diffraction coherence intensity of the target object. The actual diffraction coherence intensity can be obtained by single exposure imaging or less exposure imaging without lateral scanning, which can realize rapid full-field imaging of the target object in the two-dimensional direction, and also greatly improve the lateral spatial resolution. Moreover, in some examples, the actual diffraction coherence intensity can be used to simultaneously reconstruct the output wave functions of multiple output wavelengths through single exposure imaging, without the need for one exposure imaging for each output wavelength, which can further improve the detection speed. Therefore, compared with the existing time-domain OCT imaging system, the three-dimensional tomographic imaging method of the present application can greatly improve the imaging speed.

[0087] Moreover, when the OCT system images the internal microstructure of an object, obtaining a cross-sectional tomographic image requires sampling the interference spectrum in a uniform wavenumber space and linear correction of the interference pattern, and it is impossible to directly obtain the imaging information of a single-layer cross section; however, in the embodiment of the present application, the corresponding output wave functions of different output wavelengths are reconstructed, and the imaging information of each layer can be directly obtained using the Wiener-Hinchin theorem. In addition, since the imaging information of the object obtained in the embodiment of the present application is obtained by coherent diffraction imaging, it contains amplitude information and phase information, wherein the amplitude information reflects the absorption of the image, and the phase information contains the phase delay distribution; compared with the traditional OCT technology that can only provide absorption images, the embodiment of the present application can provide more phase information.

[0088] The three-dimensional tomography method in the embodiment of the present application can provide richer spectral information, which is helpful to obtain the detailed structure and composition information of the target object, and the measuring device is simpler, without the need for a complex interferometer structure and subsequent instruments such as a spectrometer. Only a multi-wavelength light source and a planar array detector are required to build the measuring device, which greatly reduces the complexity and cost of the system. Since the multi-wavelength light source system can freely adjust the required wavelength and is suitable for different fields and imaging depth requirements, the three-dimensional tomography method in the present application has a wider range of applications.

[0089] Compared with the traditional OCT technology, in some examples of the present application, the transmittance of each pixel point in the horizontal direction can also be obtained. For example, the actual diffraction coherence intensity is obtained based on the diffraction pattern detected by the target object under the simultaneous or separate action of the light beams of different emission wavelengths. After obtaining the diffraction pattern, a one-dimensional spectrum data array is constructed for each pixel point in the diffraction pattern according to the emission wavelength based on the diffraction pattern; the one-dimensional spectrum data array of each pixel point is inverse Fourier transformed to obtain the autocorrelation function of the pixel point. The autocorrelation function reflects the transmittance of the target object at the pixel point along the depth direction.

[0090] In the present application, there are multiple methods for acquiring the actual diffraction coherence intensity in step S101. In one example, the actual diffraction coherence intensity is the actual diffraction coherence total intensity detected by the target object under the simultaneous action of the light beams of different emission wavelengths. Figure 2a This is a schematic diagram of the optical path principle of multi-wavelength coherent modulation imaging provided by an embodiment of the present application. Figure 2b It is a schematic diagram of an embodiment of the method for obtaining actual diffraction coherence intensity of the present application.

[0091] like Figure 2a As shown, Figure 2a The number of wavelengths is 3 for illustration, and the number of wavelengths is not limited in this application. 1 ...3 At the same time, the light field is irradiated onto the target object, and the light field after interacting with the target object is propagated to the modulator plane through diffraction. Optionally, an aperture stop is also provided on one side of the target object to adjust the size of the light beam. After each light field is modulated by the modulator, an outgoing wave is formed from the modulator. The three outgoing waves propagate to the detector through diffraction, and finally the total diffraction intensity image I is obtained at the detector. λ .

[0092] like Figure 2b As shown, the method includes: the method for obtaining the actual diffraction coherence intensity includes:

[0093] Step S201, using illumination light beams of different wavelengths to simultaneously illuminate a target object to obtain output waves.

[0094] Generate multiple different wavelengths λ according to the preset wavelength interval and wavelength range 1 ,λ 2 , ..., λ n , where each photon beam has a specified bandwidth and wavelength distribution. In one example, the multiple photon beams of different wavelengths can be laser beams of different wavelengths emitted simultaneously by a multi-wavelength light source module. Each photon beam is simultaneously irradiated onto a target object to obtain an output wave function corresponding to multiple different output wavelengths.

[0095] Step S202: modulate the outgoing wave using a modulator to obtain a modulated outgoing wave.

[0096] Optionally, the modulator is moved axially during modulation so that the modulator interacts with the outgoing wave of the target object at the optimal modulation position. If the modulator is too far away from the detector, the spot will be too large, and the subsequent detector will not be able to receive all the diffraction information, resulting in information loss that affects the quality of reconstruction; if the modulator is too close to the detector, the modulation effect on the outgoing wave is insufficient, which will affect the speed and convergence of the reconstruction process. In some examples, the modulator can be fixed on a precision translation stage, and the axial position of the modulator can be adjusted by axial movement of the precision translation stage to obtain the optimal modulation position.

[0097] Step S203: using a detector to detect the modulated outgoing wave to obtain actual diffraction coherence intensity.

[0098] The diffraction field of the photon beams corresponding to different wavelengths scattered by the target object is phase modulated by a calibrated modulator, and then the diffraction field is collected by a detector, and its intensity distribution diagram is recorded to obtain the actual diffraction coherence intensity. The actual diffraction coherence intensity reflects the superposition information of the diffraction coherence intensities of different output wavelengths. realOptionally, the actual diffraction coherence total intensity can be recorded by controlling the exposure time of the detector so that there are enough photons received for signal processing, but there is no overexposure that makes the information indistinguishable.

[0099] Alternatively, in some examples, the actual diffraction coherence intensity includes the actual diffraction coherence intensity detected by the target object under the action of the light beams of different exit wavelengths. When obtaining the actual diffraction coherence intensity, the target object is scanned in turn with illumination light beams of different wavelengths to obtain exit waves corresponding to different exit wavelengths, and the different exit waves are modulated by a modulator to obtain modulated exit waves, and the modulated exit waves are detected by a detector to obtain the actual diffraction coherence intensity detected by the target object under the action of the light beams of different exit wavelengths. Optionally, the illumination light beams of different wavelengths can be laser light beams of different wavelengths emitted in turn by a multi-wavelength light source module, wherein each wavelength of the light beam passes through a collimation and beam expansion device in turn, and is adjusted to a suitable beam size by an aperture diaphragm.

[0100] In the above example, the actual diffraction coherence total intensity I can be obtained by executing steps S201 to S203 through the coherent modulation imaging system. real Afterwards, the data processing device can be used to reconstruct the output wave functions of the target object corresponding to different output wavelengths.

[0101] in, Figure 1 In step S101 of the embodiment shown, there are multiple methods for reconstructing the output wave functions of the target object corresponding to different output wavelengths according to the actual diffraction coherence intensity of the target object. Figure 3 As shown, Figure 3 FIG. 1 is a schematic diagram of the mode decomposition principle of multi-wavelength coherent diffraction imaging provided by an embodiment of the present application. Figure 3 As shown, the beam λ emitted by the multi-wavelength light source 1 ... M The algorithm is decomposed into multiple independent modes that propagate independently. Specifically, the beam λ emitted by the multi-wavelength light source 1 ... M They interact with the target object to form outgoing waves O 1 ... M , propagates to the detector plane through diffraction, and finally obtains the diffraction intensity I at the detector plane 1 ...I M Incoherent superposition to obtain the final diffraction intensity map I λ , completing the entire multi-wavelength propagation process. In terms of algorithm, this model can be used to simulate the multi-wavelength propagation process in the actual experimental process, so as to iteratively converge the sample information of the corresponding wavelength.

[0102] In one example, if Figure 4 As shown, Figure 4 1 is a schematic diagram of an embodiment of a method for reconstructing the output wave functions of the target object corresponding to different output wavelengths according to the actual diffraction coherence intensity of the target object according to the present application. The method comprises:

[0103] Step S401, obtaining an initial function of an outgoing wave of the target object at a sample surface.

[0104] In some examples, the initial function of the outgoing wave at the sample surface is the initial function of the outgoing wave of the target object at the sample surface under the simultaneous action of different outgoing wavelengths. Alternatively, in some examples, the multiple initial functions of the outgoing wave at the sample surface are the initial functions of the outgoing wave of the target object at the sample surface under the action of different outgoing wavelengths respectively.

[0105] By respectively initializing the illumination functions of different emission wavelengths and the object functions of the target object, the initial function of the emission wave of the target object after being acted upon simultaneously or separately by light beams of different emission wavelengths can be obtained. In the example where the initial function of the emission wave at the sample surface is the initial function of the emission wave of the target object when the sample surface is simultaneously acted upon by different emission wavelengths, the emission wave of the target object under the action of illumination light beams of different emission wavelengths is simulated, and the emission wave is regarded as a superposition of multiple layers of complex amplitude information propagated to the emission surface of the target object by illumination light beams of different wavelengths.

[0106] The output wave function obtained after the target object is acted upon by light beams of various output wavelengths is expressed as follows:

[0107]

[0108] in, It is expressed as the illumination function corresponding to N different emission wavelengths, Indicates that the target object is transmitted by a wavelength of λ i The output wave function obtained after the illumination light beam is acted upon, i=1, ..., N. The output wave function is used to characterize the complex amplitude information. represents the superposition operator of the complex amplitude information corresponding to different layers. AS{·} represents the angular spectrum propagation operator of the complex amplitude between layers of the target object. layer(k) represents the complex amplitude information of the kth layer of the target object, where k = 1, 2, ..., K. d(Kk) represents the distance from the kth layer of the target object to the final exit surface.

[0109] Step S402, taking the initial function of the outgoing wave at the sample surface as input, performing at least one iteration to obtain an updated function of the outgoing wave at the sample surface.

[0110] Wherein, in each iteration: the outgoing wave of the sample surface is modulated and demodulated according to the modulator function, and the actual diffraction coherence intensity is used to constrain the amplitude of the modulated outgoing wave between the modulation and the demodulation.

[0111] Specifically, the forward propagation process and the reverse propagation process of the measurement system are simulated in each round of iteration, and the input of each round of iteration is used as the input of the next round of iteration. In the forward propagation process of the simulated measurement system, the simulated output wave propagates forward from the target object surface to the modulator surface, and then propagates forward from the modulator surface to the detector surface; in the reverse propagation process of the simulated measurement system, the simulated output wave propagates backward from the detector surface to the modulator surface, and then propagates backward from the modulator surface to the sample surface. At the beginning of the reverse propagation process of the simulated measurement system, the actual diffraction coherence intensity is also used for intensity constraint to achieve reconstruction of the output wave of the target object.

[0112] The actual diffraction coherence intensity is the actual diffraction coherence total intensity detected by the target object under the simultaneous action of the light beams of different emission wavelengths (i.e., the superposition information I of the actual diffraction coherence intensities corresponding to different emission wavelengths). real ), the simulated output wave of the sample surface is the output wave obtained after light beams of different output wavelengths act on the target object at the same time, and the output wave is used as the input of the iterative algorithm for at least one round of iteration, and in each round of iteration, the actual diffraction coherence total intensity is used to constrain the amplitude of the output wave.

[0113] In the example where the actual diffraction coherence intensity includes the actual diffraction coherence intensity detected when the target object is acted upon by light beams of different emission wavelengths, the simulated emission waves of the sample surface are different emission waves obtained when light beams of different emission wavelengths act upon the target object, and at least one round of iteration is performed using the emission waves corresponding to each emission wavelength as input to the iterative algorithm. In each round of iteration, the actual diffraction coherence intensity corresponding to the emission wavelength is used to constrain the amplitude of the emission wave to obtain an emission wave update function corresponding to the emission wavelength.

[0114] Step S403, separating the outgoing wave reconstruction functions of the target object corresponding to the different outgoing wavelengths from the outgoing wave update function at the sample surface.

[0115] In the example where the outgoing wave is the outgoing wave of the target object at the sample surface under the action of different outgoing wavelengths, after the iterative algorithm is completed, the outgoing wave update function corresponding to each outgoing wavelength can be obtained, and the illumination function can be separated from each outgoing wave update function to obtain the outgoing wave reconstruction function corresponding to each outgoing wavelength.

[0116] In the example where the outgoing wave is the outgoing wave of the target object at the sample surface under the simultaneous action of different outgoing wavelengths, when the outgoing wave update function at the sample surface is obtained after reconstruction, the constraint of the known illumination function of each outgoing wavelength is also introduced to separate the illumination function from the outgoing wave update function, and obtain the outgoing wave reconstruction functions of the target object corresponding to different outgoing wavelengths. In one example, according to the following formula,

[0117]

[0118] The outgoing wave update function of the target object can be solved as:

[0119]

[0120] in, Represents the conjugate information of the illumination function corresponding to different emission wavelengths; Represents the update function of the outgoing wave corresponding to different wavelengths of the target object; represents the updated illumination function of different wavelengths; DI{·} represents an operator for separating sample information from illumination information. The operator is used to separate the object function from the illumination function and is not limited to a specific implementation method.

[0121] Optionally, the ePIE algorithm can also be used to separate the object function from the illumination function, so that the illumination function can be updated while separating the illumination information from the sample information. In an example, the output wave reconstruction function corresponding to each output wavelength can be calculated according to the following formula:

[0122]

[0123]

[0124] Where i = 1, ..., N. Where represents the updated illumination function corresponding to a certain output wavelength; It represents the conjugate information of the updated output wave function of the target object corresponding to a certain output wavelength; α is the update coefficient, which can be between 0 and 1, for example, set to 0.9.

[0125] The following takes the actual diffraction coherence intensity as the actual diffraction coherence total intensity detected by the target object under the simultaneous action of the light beams of different emission wavelengths as an example. Figure 5 The iterative process is explained with examples. Figure 5 As stated, Figure 5 It is a schematic diagram of an embodiment of an iteration in the iterative algorithm in the three-dimensional tomography method of the present application. The iterative algorithm includes a forward propagation process and a reverse propagation process.

[0126] Forward propagation process

[0127] Step S501: constraining the outgoing wave of the target object by using the size of the illumination area on the sample surface to obtain the outgoing wave on the sample surface.

[0128] The illumination area size constraint is represented by S. In an example where an aperture stop is used to adjust the light beam size to a suitable size, the illumination area is the illumination area after the light beam passes through the aperture stop. They represent the outgoing wave functions of the illumination beams of different wavelengths corresponding to the target object after being constrained by the illumination area size S. Then:

[0129]

[0130] In the above formula, They represent the outgoing wave functions on the sample surface in the previous iteration. In the first iteration, the They represent the initial functions of the outgoing wave β is a parameter with a range of [0, 1].

[0131] Step S502: propagate the outgoing wave from the sample surface forward to the modulator surface, and interact with the modulator to form the outgoing wave from the modulator surface.

[0132] Optionally, the output wave function of the modulator surface formed by the modulator is expressed by the following formula:

[0133]

[0134] Where, M{·} represents the modulation operator; F1{·} represents the propagation operator from the sample surface to the modulator surface; The modulator surface corresponds to the output waves of different wavelengths. Optionally, M and F 1 Can be a function of wavelength.

[0135] Optionally, the outgoing wave of the sample surface obtained in step S1 is propagated to the modulator surface through the light field angular spectrum propagation model for modulation. Then the outgoing wave function formed by the modulator surface is expressed as:

[0136]

[0137] Among them, AS{·} represents the light field angular spectrum propagation model, and M{·} represents the modulation operator.

[0138] Step S503: forward propagate the outgoing wave of the modulator surface to the detector surface through the light field propagation model.

[0139] The following formula represents:

[0140]

[0141] in, are the output wave functions of the detector surface corresponding to different output wavelengths; F 2 {·} represents the propagation operator from the modulator surface to the detector surface. Optionally, F 2 {·} can include Fresnel diffraction, Fraunhofer diffraction or angular spectrum propagation, etc.

[0142] Step S504: Superimpose the light field intensities corresponding to different emission wavelengths on the detector surface to obtain the total light field intensity information after superposition. The following formula is used to represent it:

[0143]

[0144] Among them, I(x D ,y D ) is the intensity information of the total diffracted light field after superposition on the detector surface; Represents the light field intensity superposition operator corresponding to different wavelengths.

[0145] Back propagation process

[0146] Step S505: For the light field intensity on the detector surface during the forward propagation process, according to the superposition information I of the actual diffraction coherence intensity real Perform intensity constraints to obtain the output wave functions corresponding to different output wavelengths after the detector surface is updated

[0147] In an example of intensity constraint, the estimated total diffraction intensity of the detector surface is superimposed with information I(x D ,y D ) is replaced by I real , the phase remains unchanged, and the updated output wave function corresponding to different wavelengths can be expressed as follows:

[0148]

[0149] Step S506: propagate the outgoing wave from the detector surface in reverse direction to the modulator surface, and demodulate it through the modulator.

[0150] The updated output wave functions corresponding to different wavelengths propagate back to the modulator surface, forming a series of demodulated output wave functions of the detector surface. The output wave function of the modulator surface is obtained by demodulation through the known modulator information, which is expressed as follows:

[0151]

[0152] in, To update and demodulate the output wave functions corresponding to different wavelengths; M represents the back propagation operator from the modulator surface to the detector surface; -1{·} represents the demodulation operator of the modulator.

[0153] Step S407: propagate the outgoing wave from the modulator surface back to the sample surface to obtain an update function of the outgoing wave on the sample surface.

[0154] After the outgoing wave function of the modulator surface is obtained according to step S406, the defocus positions corresponding to different wavelengths are used to propagate inversely to the target object surface, as shown in the following formula:

[0155]

[0156] in, is the update function of the outgoing wave corresponding to different wavelengths on the sample surface; represents the modulator plane to sample plane propagation operator. In step S2, F 1 In the example of using AS{·} (i.e., the light field angular spectrum propagation model), Can be AS -1 {·}, which is the inverse-angle spectrum propagation operator from the sample surface to the modulator surface.

[0157] After one round of iteration, the output wave update function of the target object at the sample surface obtained after the iteration is used as the input of the next round of iteration, and the forward propagation process and the reverse propagation process are repeated. Alternatively, in some examples, the output wave update function of the target object at the sample surface obtained after the iteration can be separated to obtain the separated illumination function and the output wave function corresponding to each output wavelength, and then the two types of functions are interacted to obtain the output wave update function of the target object at the sample surface as the input of the next round of iteration. In the example where the illumination light is structured light, the sample information and the illumination information are separated and then merged at the sample surface, which can avoid the situation where the sample information and the illumination information are merged together after all iterations and are difficult to separate.

[0158] In this way, after at least two rounds of iteration, the updated function of the output wave of the target object corresponding to different wavelengths obtained in the last iteration is used as the final function of the output wave of the target object corresponding to different wavelengths. There are multiple conditions for stopping the iteration. For example, when the guessed detector surface total diffraction intensity superposition information I(x D ,y D ) and the superposition information of the actual diffraction coherence intensity I real When the error between them is less than the preset threshold, it means that the calculated diffraction light field of the reconstructed target object is very close to the actually measured diffraction light field, and the algorithm reaches a convergence state. Therefore, the iteration is stopped, and the updated function of the outgoing wave of the target object corresponding to different wavelengths obtained in this iteration is used as the final function of the outgoing wave of the target object.

[0159] The present application also provides a three-dimensional tomography device. Figure 6 As shown, Figure 6 Schematic diagram of an embodiment of a three-dimensional tomography device of the present application. The three-dimensional tomography device 600 includes:

[0160] A reconstruction module 601 is used to reconstruct the exit wave functions of the target object corresponding to different exit wavelengths according to the actual diffraction coherence intensity of the target object, so as to obtain the exit wave reconstruction functions of the target object corresponding to the different exit wavelengths, wherein the exit wave reconstruction functions include amplitude information and phase information; wherein the actual diffraction coherence intensity is the actual diffraction coherence total intensity detected by the target object under the simultaneous action of the light beams of the different exit wavelengths, or includes the actual diffraction coherence intensity detected by the target object under the action of the light beams of the different exit wavelengths;

[0161] The imaging module 602 is used to obtain imaging information of the target object in other dimensions according to the outgoing wave reconstruction functions corresponding to the different outgoing wavelengths of the target object.

[0162] Optionally, when the imaging module 602 obtains the imaging information of the target object in other dimensions according to the exit wave reconstruction functions of the target object corresponding to the different exit wavelengths, the imaging module 602 is specifically used to transmit the exit wave reconstruction functions of the target object corresponding to the different exit wavelengths to the layers at different depths of the target object to obtain the complex amplitude information of the target object corresponding to the different exit wavelengths in each layer of the layers at different depths; and superimpose the complex amplitude information of the target object corresponding to different wavelengths in each layer to obtain the imaging information on the layer.

[0163] Optionally, for each of the layers at different depths, a diffraction propagation operator is used to calculate complex amplitude information of an outgoing wave reconstruction function of the target object corresponding to the different outgoing wavelengths on the layer.

[0164] Optionally, the diffraction propagation operator is an angular spectrum propagation operator.

[0165] Optionally, the number of different exit wavelengths is N. When the imaging module 602 obtains the imaging information of the target object in other dimensions according to the exit wave reconstruction functions of the target object corresponding to the different exit wavelengths, the imaging module 602 is specifically used to refocus the exit wave reconstruction functions of the target object corresponding to the different exit wavelengths on N layers at different depths of the target object to obtain the complex amplitude information of each layer in the N layers at different depths.

[0166] Optionally, an angular spectrum diffraction algorithm may be used to refocus the outgoing wave reconstruction functions of the target object corresponding to the different outgoing wavelengths on N layers at different depths of the target object.

[0167] Optionally, the actual diffraction coherence intensity is obtained based on a diffraction pattern detected when the target object is acted upon simultaneously or separately by light beams of different emission wavelengths; the three-dimensional tomography imaging device 600 also includes an acquisition module for constructing a one-dimensional spectrum data array for each pixel point in the diffraction pattern according to the emission wavelength based on the diffraction pattern; and performing an inverse Fourier transform on the one-dimensional spectrum data array of each pixel point to obtain an autocorrelation function of the pixel point.

[0168] Optionally, when the reconstruction module 601 reconstructs the exit wave functions of the target object corresponding to different exit wavelengths according to the actual diffraction coherence intensity of the target object to obtain the exit wave reconstruction functions of the target object corresponding to the different exit wavelengths, it is specifically used to:

[0169] Acquire an initial function of an outgoing wave of the target object at a sample surface, wherein the initial function of the outgoing wave at the sample surface is an initial function of an outgoing wave of the target object at the sample surface under the simultaneous action of different outgoing wavelengths;

[0170] Taking the initial function of the outgoing wave at the sample surface as input, performing at least one iteration to obtain an updated function of the outgoing wave at the sample surface, wherein in each iteration: modulating and demodulating the outgoing wave at the sample surface according to the modulator function, and using the actual diffraction coherence intensity to perform amplitude constraint on the modulated outgoing wave between the modulation and the demodulation, wherein the actual diffraction coherence intensity is the actual diffraction coherence total intensity detected by the target object under the simultaneous action of the different outgoing wavelengths;

[0171] The outgoing wave reconstruction functions of the target object corresponding to the different outgoing wavelengths are separated from the outgoing wave update function at the sample surface.

[0172] Optionally, when the reconstruction module 601 reconstructs the exit wave functions of the target object corresponding to different exit wavelengths according to the actual diffraction coherence intensity of the target object to obtain the exit wave reconstruction functions of the target object corresponding to the different exit wavelengths, it is specifically used to:

[0173] Acquire a plurality of initial functions of outgoing waves of the target object at the sample surface, wherein the plurality of initial functions of outgoing waves at the sample surface are initial functions of outgoing waves of the target object at the sample surface under the action of different outgoing wavelengths respectively;

[0174] The following steps are performed for each outgoing wave initial function at the sample surface corresponding to each wavelength beam:

[0175] Taking the initial function of the outgoing wave as input, performing at least one iteration to obtain an updated function of the outgoing wave at the sample surface;

[0176] Separating an outgoing wave reconstruction function of the target object corresponding to the wavelength light beam from the outgoing wave update function at the sample surface;

[0177] Wherein, in each iteration: the outgoing wave of the sample surface is modulated and demodulated according to the modulator function, and the actual diffraction coherence intensity is used to constrain the amplitude of the modulated outgoing wave between the modulation and demodulation; the actual diffraction coherence intensity is the actual diffraction coherence intensity detected by the target object under the action of the wavelength light beam.

[0178] The present application also provides a three-dimensional tomography device. Figure 7 As shown, Figure 7 7 is a schematic diagram of an embodiment of a three-dimensional tomography device of the present application. The three-dimensional tomography device 700 includes a processor 701 and a memory 702. The memory 702 stores executable codes, and when the executable codes are executed by the processor 701, the processor executes any one of the three-dimensional tomography methods described above.

[0179] The present application also provides a three-dimensional tomography system. Figure 8 As shown, Figure 8 800 includes an illumination light source 801, a modulator 803, a detector 804, and a 3D tomography device 805. In some examples, the 3D tomography device and the detector may be integrated into one device, or may be two separate devices from the detector, which is not limited here.

[0180] The illumination light source 801 is used to emit light beams of different emission wavelengths simultaneously or sequentially to illuminate the target object 802 to obtain an emission wave. The modulator 803 is used to modulate the emission wave to obtain a modulated emission wave. The detector 804 is used to detect the modulated emission wave to obtain the actual diffraction coherence intensity of the target object 802. The three-dimensional tomography device 805 is used to obtain three-dimensional imaging information of the target object according to the actual diffraction coherence intensity of the target object. Optionally, the three-dimensional tomography device 805 can be as follows: Figure 7 The three-dimensional tomography device is shown.

[0181] The embodiments of the present application have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The selection of terms used herein is intended to best explain the principles of the embodiments, practical applications, or improvements to the technology in the market, or to enable other persons of ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. A three-dimensional tomography method, It is characterized in that include: Reconstructing the exit wave functions of the target object corresponding to different exit wavelengths respectively according to the actual diffraction coherence intensity of the target object, and obtaining the exit wave reconstruction functions of the target object corresponding to the different exit wavelengths respectively, wherein the exit wave reconstruction functions include amplitude information and phase information; wherein the actual diffraction coherence intensity is the actual diffraction coherence total intensity detected by the target object under the simultaneous action of the light beams of the different exit wavelengths, or includes the actual diffraction coherence intensity detected by the target object under the action of the light beams of the different exit wavelengths respectively; Imaging information on different layers of the target object is obtained according to the outgoing wave reconstruction functions corresponding to the different outgoing wavelengths of the target object.

2. The three-dimensional tomography method according to claim 1, It is characterized in that The step of obtaining imaging information on different layers of the target object according to the output wave reconstruction functions corresponding to the different output wavelengths of the target object includes: Transmitting the outgoing wave reconstruction functions of the target object corresponding to the different outgoing wavelengths to the layers at different depths of the target object to obtain the complex amplitude information of the target object corresponding to the different outgoing wavelengths at each layer in the layers at different depths; The complex amplitude information of the target object corresponding to different wavelengths on each layer is superimposed to obtain imaging information on the layer.

3. The three-dimensional tomography method according to claim 2, It is characterized in that The step of reconstructing the outgoing waves of the target object corresponding to the different outgoing wavelengths to layers at different depths of the target object includes: For each of the layers at different depths, the diffraction propagation operator is used to calculate the complex amplitude information of the outgoing wave reconstruction function of the target object corresponding to the different outgoing wavelengths on the layer.

4. The three-dimensional tomography method according to claim 1, It is characterized in that The number of the different emission wavelengths is N, and the acquisition of imaging information on different layers of the target object according to the emission wave reconstruction functions corresponding to the different emission wavelengths of the target object includes: The outgoing wave reconstruction functions of the target object corresponding to the different outgoing wavelengths are refocused on N layers at different depths of the target object to obtain complex amplitude information of each layer in the N layers at different depths.

5. The three-dimensional tomography method according to claim 1, It is characterized in that The actual diffraction coherence intensity is obtained according to the diffraction pattern detected by the target object under the simultaneous or separate action of the light beams of different emission wavelengths; The method further comprises: According to the diffraction pattern, constructing a one-dimensional spectrum data array for each pixel point in the diffraction pattern according to the emission wavelength; An inverse Fourier transform is performed on the one-dimensional spectrum data array of each pixel point to obtain information of different depths of the target object at the pixel point.

6. The three-dimensional tomography method according to claim 1, It is characterized in that The step of reconstructing the output wave functions of the target object under different output wavelengths according to the actual diffraction coherence intensity of the target object to obtain the reconstructed output wave functions of the target object corresponding to the different output wavelengths includes: Acquire an initial function of an outgoing wave of the target object at a sample surface, wherein the initial function of the outgoing wave at the sample surface is an initial function of an outgoing wave of the target object at the sample surface under the simultaneous action of different outgoing wavelengths; Taking the initial function of the outgoing wave at the sample surface as input, performing at least one iteration to obtain an updated function of the outgoing wave at the sample surface, wherein in each iteration: modulating and demodulating the outgoing wave at the sample surface according to the modulator function, and using the actual diffraction coherence intensity to perform amplitude constraint on the modulated outgoing wave between the modulation and the demodulation, wherein the actual diffraction coherence intensity is the actual diffraction coherence total intensity detected by the target object under the simultaneous action of the different outgoing wavelengths; The outgoing wave reconstruction functions of the target object corresponding to the different outgoing wavelengths are separated from the outgoing wave update function at the sample surface.

7. The three-dimensional tomography method according to claim 1, It is characterized in that The step of reconstructing the output wave functions of the target object under different output wavelengths according to the actual diffraction coherence intensity of the target object to obtain the reconstructed output wave functions of the target object corresponding to the different output wavelengths includes: Acquire a plurality of initial functions of outgoing waves of the target object at the sample surface, wherein the plurality of initial functions of outgoing waves at the sample surface are initial functions of outgoing waves of the target object at the sample surface under the action of different outgoing wavelengths respectively; The following steps are performed for each outgoing wave initial function at the sample surface corresponding to each wavelength beam: Taking the initial function of the outgoing wave as input, performing at least one iteration to obtain an updated function of the outgoing wave at the sample surface; Separating an outgoing wave reconstruction function of the target object corresponding to the wavelength light beam from the outgoing wave update function at the sample surface; Wherein, in each iteration: the outgoing wave of the sample surface is modulated and demodulated according to the modulator function, and the actual diffraction coherence intensity is used to constrain the amplitude of the modulated outgoing wave between the modulation and demodulation; the actual diffraction coherence intensity is the actual diffraction coherence intensity detected by the target object under the action of the wavelength light beam.

8. The method according to claim 1, It is characterized in that The method further comprises: The target object is irradiated with light beams of different emission wavelengths simultaneously or sequentially to obtain emission waves; Modulating the output wave using a modulator to obtain a modulated output wave; The modulated outgoing wave is detected by a detector to obtain the actual diffraction coherence intensity of the target object.

9. A three-dimensional tomography device, It is characterized in that include: A reconstruction module, used to reconstruct the exit wave functions of the target object corresponding to different exit wavelengths according to the actual diffraction coherence intensity of the target object, so as to obtain the exit wave reconstruction functions of the target object corresponding to the different exit wavelengths, wherein the exit wave reconstruction functions include amplitude information and phase information; wherein the actual diffraction coherence intensity is the actual diffraction coherence total intensity detected by the target object under the simultaneous action of the light beams of the different exit wavelengths, or includes the actual diffraction coherence intensity detected by the target object under the action of the light beams of the different exit wavelengths; The imaging module is used to obtain imaging information of the target object in other dimensions according to the outgoing wave reconstruction functions corresponding to the different outgoing wavelengths of the target object.

10. A three-dimensional tomography device, It is characterized in that include: processor; as well as A memory having executable codes stored thereon, which, when executed by the processor, causes the processor to execute the method according to any one of claims 1 to 7.

11. A three-dimensional imaging system, It is characterized in that include: An illumination light source, used for emitting light beams of different emission wavelengths simultaneously or sequentially to illuminate a target object to obtain an emission wave; A modulator, used for modulating the outgoing wave to obtain a modulated outgoing wave; A detector, used to detect the modulated outgoing wave to obtain the actual diffraction coherence intensity of the target object; The three-dimensional tomography device according to claim 10 is used to obtain three-dimensional imaging information of the target object based on the actual diffraction coherence intensity of the target object.

Images