All-optical field imaging camera, imaging method therefor, and all-optical field imaging device

Abstract

The present invention provides a full-field imaging camera, including an imaging component and a two-dimensional array detector sequentially arranged to form an image plane intensity information collection system, an imaging component, a Fourier transform lens and a two-dimensional array detector sequentially arranged to form a spatial Fourier spectrum intensity information collection system, and an arithmetic processor communicatively connected to the detector, the imaging component receives illumination light from an object to be measured to form an imaging light, the imaging light is imaged on a detection surface of the detector to form a first image plane, the imaging light is imaged in front of the Fourier transform lens to form a second image plane, and a spatial Fourier spectrum intensity information plane is formed on the detection surface of the detector on the focal plane after the Fourier transform lens. The present invention further provides a corresponding imaging method and a full-field imaging device. The full-field imaging camera of the present invention solves the problems of existing phase imaging technology, such as high sampling rate requirement, need for overlap to obtain redundant information, slow algorithm convergence, etc.

Description

[Technical Field]

[0001] The present invention relates to the field of imaging, and more particularly to a full-light field imaging camera and imaging method thereof, and a full-light field imaging device. [Background technology]

[0002] In the imaging process, the phase information of an object often plays a more important role than the intensity information of the object. However, in actual imaging, the imaging detector can only detect the intensity information of the image, and the corresponding phase information is lost, so the important phase information in the image is lost in imaging. In order to restore the phase information of the image, phase imaging methods have made great progress in recent years, and mainly include the following categories:

[0003] The first method is coherent diffraction imaging (CDI), which uses coherent light to illuminate a sample, diffracting the light from the sample into the far field to form a spatial Fourier spectrum intensity distribution of the object in the far field. The spatial Fourier spectrum intensity distribution is then used as a constraint for collection, and the amplitude and phase information of the object is obtained by methods such as oversampling and iterative Fourier calculation, thereby achieving object imaging.

[0004] The second method is Fourier photometry (FPM), which involves illuminating a sample from various angles and collecting the light using a microscope imaging system. Each angle of light corresponds to a different real image plane intensity distribution. These overlapping real image plane intensity distributions are then used as constraints to restore the amplitude and phase information through Fourier iteration, thereby achieving the imaging of the object.

[0005] The third method is holography, which involves introducing a reference beam and causing the diffracted light that passes through the object to interfere with the reference beam to obtain a hologram. In this case, the contrast and shape (or position) information of the interference fringes contain information about the wavefront amplitude and phase of the object, respectively. By reconstructing the wavefront of the hologram, the amplitude and phase information of the object can be obtained, thereby achieving clear imaging of the object.

[0006] Since the phase information is lost in the actual image acquisition process, additional information is required as a constraint in the phase reconstruction process. However, the above methods can also reconstruct the image of the object by resolving the phase. However, each method has its own drawbacks, which are mainly reflected in the following points:

[0007] 1. The first method requires high sampling requirements and can only detect partial information in the spatial Fourier spectrum plane, which is not sufficient to obtain phase information. To obtain sufficient constraints, it is necessary to improve sampling and create redundant information, which requires oversampling and is likely to cause the algorithm to fail to converge.

[0008] 2. The second method also requires a large amount of information redundancy, but since only partial information on the real image plane is detected, it is not enough to simply solve the phase information. In order to obtain sufficient constraints, this method can achieve a certain degree of overlap detection for the Fourier spatial spectrum distributions for each of two adjacent angles, resulting in high information redundancy and a shorter imaging time.

[0009] 3. The three methods require the introduction of an additional reference beam to cause the diffracted beam to interfere, which makes the optical path relatively complicated and increases the stability requirements. At the same time, in the process of solving the phase using holography, problems such as conjugate images occur, which makes the algorithm unable to converge. Summary of the Invention [Problem to be solved by the invention]

[0010] The object of the present invention is to provide a full-light field imaging camera, an imaging method therefor, and a full-light field imaging apparatus, thereby solving the problems of existing phase imaging techniques, such as high sampling rate requirements, the need for overlap to acquire redundant information, and slow algorithm convergence. [Means for solving the problem]

[0011] In order to achieve the above object, the present invention provides a full-light-field imaging camera, comprising: an imaging component and a first two-dimensional array detector sequentially arranged along a direction of an optical path to form an image plane intensity information collection system; the imaging component, a Fourier transform lens and a second two-dimensional array detector sequentially arranged along the direction of the optical path to form a spatial Fourier spectrum intensity information collection system; and an arithmetic processor communicatively connected to the first two-dimensional array detector and the second two-dimensional array detector, wherein the imaging component is configured to receive illumination light from an object to be measured and provide imaging light of the object to be measured, the imaging light being imaged onto a detection surface of the first two-dimensional array detector to form a first image plane, the imaging light being imaged at a position at a known distance in front of a Fourier transform lens to form a second image plane, and a spatial Fourier spectrum plane being formed on the detection surface of the second two-dimensional array detector on a focal plane after the Fourier transform lens.

[0012] Preferably, the number of the imaging components is one, and a beam splitter is installed between the imaging component and the Fourier transform lens, or the number of the imaging components is two, and a beam splitter is installed in front of the two imaging components, one of the first image plane and the second image plane is formed by direct imaging of the imaging light, and the other is formed by imaging the imaging light after it is reflected by the beam splitter, and the first two-dimensional array detector and the second two-dimensional array detector are two two-dimensional array detectors or the same movable two-dimensional array detector.

[0013] Preferably, the first two-dimensional array detector and the second two-dimensional array detector are two different two-dimensional array detectors that detect first image plane intensity information and spatial Fourier spectrum plane intensity information, respectively, or are the same two-dimensional array detector that can be moved along the optical path, in which case the Fourier transform lens is movable, and switching between an image plane intensity information collection system and a spatial Fourier spectrum intensity information collection system is performed by moving the two-dimensional array detector and moving the Fourier transform lens in and out of the optical path.

[0014] Preferably, the calculation processor is configured to perform step S1 of receiving the image plane intensity information and the spatial Fourier spectrum intensity information, and performing multiple Fourier iterations using the image plane intensity information and the spatial Fourier spectrum intensity information as constraints for the Fourier iteration to obtain amplitude spatial distribution information and phase spatial distribution information of the target object to be measured, thereby realizing total optical field imaging, wherein the method of the Fourier iteration includes, but is not limited to, a Gerchberg-Saxton algorithm, a hybrid input-output algorithm, and a Yang-Gu algorithm.

[0015] The imaging light is imaged onto a focal plane in front of a Fourier transform lens.

[0016] In another aspect, the present invention provides an imaging method for a full light field imaging camera, comprising:

[0017] a step S1' of providing an imaging component so that illumination light illuminates an object to be measured and then passes through the imaging component to form imaging light of the object to be measured, disposing a detection surface of a first two-dimensional array detector at a first image plane formed by imaging the imaging light, disposing a Fourier transform lens at a position at a known distance from the second image plane, and disposing a second two-dimensional array detector at a focal plane after the Fourier transform lens, and acquiring image plane intensity information and spatial Fourier spectrum intensity information of the object to be measured by collecting the first two-dimensional array detector and the second two-dimensional array detector;

[0018] Step S2' is to perform step S1, which realizes total optical field imaging, by uploading the image plane intensity information and spatial Fourier spectrum intensity information of the object to be measured obtained in step S1' to a calculation processor, and using the calculation processor to perform multiple Fourier iterations using the image plane intensity information and spatial Fourier spectrum intensity information as constraints for the Fourier iterations to obtain amplitude spatial distribution information and phase spatial distribution information of the object to be measured.

[0019] Preferably, step S1' further includes a step in which the number of imaging components is one and a beam splitter is disposed between the imaging component and the first two-dimensional array detector, or the number of imaging components is two and a beam splitter is disposed in front of the two imaging components, so that a first image plane is formed by direct imaging of the imaging light and a second image plane is formed by imaging the imaging light after it is reflected by the beam splitter.

[0020] Preferably, the illumination light is coherent light or partially coherent light with a known degree of coherence, the partially coherent light meeting the criterion of quasi-monochromaticity.

[0021] In another aspect, the present invention provides a total optical field imaging device based on a total optical field imaging camera, including a laser, an object to be measured, and an imaging lens group, all of which are on the same optical axis, and the total optical field imaging camera as described above, wherein the imaging lens group is an imaging objective lens, or an imaging objective lens and an imaging lens, and the object to be measured is located on the focal plane of the imaging objective lens of the imaging lens group.

[0022] In another aspect, a total light field imaging device based on a total light field imaging camera includes the total light field imaging camera described above, wherein the total light field imaging device is a microscope, a camera, or a telescope and remote sensing device, and the imaging components of the total light field imaging camera include an imaging lens component corresponding to the microscope objective lens, a photographic lens component corresponding to the camera, or a telescope and remote sensing imaging component corresponding to the telescope and remote sensing device. [Effects of the Invention]

[0023] The method and apparatus for realizing a full-optical field imaging camera provided by the present invention uses the intensity distribution on the image plane, the spatial Fourier spectrum intensity distribution, and the lens transformation as constraints, obtains the amplitude and phase of the imaging object through Fourier iteration, and realizes full-optical field imaging. Therefore, compared with existing phase imaging and its devices, it has the following advantages:

[0024] Existing phase imaging methods often require additional information as a constraint to resolve the phase, whether it be oversampling or reference light. The present invention simplifies the optical path design of conventional methods by using the information actually detected by two image planes, and through the dual image plane constraint, sufficient information can be obtained to resolve the phase, thereby reducing the sampling requirements and simplifying the experimental difficulty.

[0025] In existing methods, the calculation results often fail to converge or fail to converge to an optimal solution due to insufficient information on constraints. In this method, all information used as constraints is actually detected, so the information is more accurate, allowing for faster and more accurate convergence of the Fourier iterative calculation.

[0026] Therefore, the method and apparatus for realizing a full-light field imaging camera of the present invention has the advantages of effectively reducing the sampling requirements of the detector, simplifying the optical path, improving the amount of imaging information, and so on. [Brief explanation of the drawings]

[0027] [Figure 1] 1 is a structural schematic diagram of a full-light field imaging camera according to a first embodiment of the present invention;

[0028] [Figure 2] FIG. 10 is a structural schematic diagram of a total optical field imaging device based on a total optical field imaging camera according to a third embodiment of the present invention, which is used to realize total optical field imaging of frosted glass.

[0029] [Figure 3] 4 is a structural schematic diagram of a total optical field imaging device based on a total optical field imaging camera according to a fourth embodiment of the present invention, which is used in the field of microscopic imaging; DETAILED DESCRIPTION OF THE INVENTION

[0030] Hereinafter, embodiments of the present invention will be described with reference to specific examples, but those skilled in the art will easily understand other advantages and effects of the present invention from the contents disclosed herein. The present invention can be implemented or applied through different specific embodiments, and various details in this specification can be modified or changed in various ways based on different perspectives and applications without departing from the spirit of the present invention. Where not inconsistent, the following examples and features in the examples can be combined with each other.

[0031] It should be noted that the drawings provided in the following examples are merely diagrams showing the basic concepts of the present invention, and the drawings show only components related to the present invention, and are not drawn in accordance with the number, shape, size, etc. of the components in actual implementation. In actual implementation, the shape, number, and proportion of each component can be freely changed, and the arrangement of the components may also become more complex.

[0032] First Example: Whole-field imaging camera

[0033] FIG. 1 shows a structural schematic diagram of a full-light field imaging camera according to an embodiment of the present invention.

[0034] As shown in FIG. 1 , in this embodiment, the total optical field imaging camera includes an imaging component 1, a beam splitter 2, a first two-dimensional array detector 3, which are sequentially arranged on a first optical axis along the direction of the optical path, the beam splitter 2, a Fourier transform lens 4 having a focal length f, and a second two-dimensional array detector 5, which are sequentially arranged on a second optical axis perpendicular to the first optical axis along the direction of the optical path, and an arithmetic processor 6 communicatively connected to both the first two-dimensional array detector 3 and the second two-dimensional array detector 5.

[0035] The imaging component 1 is arranged downstream of the object to be measured and is configured to receive illumination light from the object to be measured and provide imaging light of the object to be measured, and the imaging light is imaged onto the detection surface of the first two-dimensional array detector 3 to directly form a first image plane 7, and the light intensity distribution on the detection surface of the first two-dimensional array detector 3 corresponds to the image plane intensity distribution, so that the imaging component 1 and the first two-dimensional array detector 3 arranged sequentially along the direction of the optical path constitute an image plane intensity information collection system, and the first two-dimensional array detector 3 collects image plane intensity information.

[0036] Here, the illumination light can be coherent light illumination or partially coherent light with a known coherence degree, and the coherence degree of the partially coherent light satisfies the criterion of quasi-monochromatism, i.e., λ / Δλ>M (λ is the wavelength of the partially coherent light, Δλ is the wavelength error range of the partially coherent light, and M is the number of pixels of the first two-dimensional array detector 3 and the second two-dimensional array detector 5 in one direction).

[0037] After being reflected by the beam splitter 2, the imaging light is imaged on the focal plane in front of the Fourier transform lens 4 to form a second image plane 8 (i.e., the distance between the second image plane 8 and the Fourier transform lens 4 is the focal length f of the Fourier transform lens 4). Since the distance between the Fourier transform lens 4 and the second two-dimensional array detector 5 is also the focal length f of the Fourier transform lens 4, the light intensity distribution on the detection plane of the second two-dimensional array detector 5 corresponds to the spatial Fourier spectral intensity information distribution. In another embodiment, there may be a situation where the distance between the second image plane 8 and the Fourier transform lens 4 is not the focal length f of the Fourier transform lens 4, but the distance between the second image plane 8 and the Fourier transform lens 4 is known. Thus, the imaging component 1, the beam splitter 2, the Fourier transform lens 4, and the second two-dimensional array detector 5, which are sequentially arranged along the optical path, constitute a spatial Fourier spectral intensity information collection system, and the second two-dimensional array detector 5 acquires the spatial Fourier spectral intensity information.

[0038] The first two-dimensional array detector 3 and the second two-dimensional array detector 5 have light receiving elements and are configured to convert the light intensity on the detection surface (i.e., the squared information of the amplitude of the light wave) into an electrical signal using the photoelectric conversion characteristics of the light receiving elements, and the light intensity on the detection surface is the image plane intensity information and spatial Fourier spectrum intensity information (expressed as an image of gray scale values). The converted electrical signal itself is dimensionless, and the unit of the light intensity on the detection surface itself is W / cm. 2 Therefore, the units of the image plane intensity information and spatial Fourier spectrum intensity information are W / cm 2 Specifically, the detected image plane intensity information is represented by f(x0, y0), and the spatial Fourier spectrum intensity information is represented by F(u0, v0), where x0, y0 represent the coordinates of the detection plane of the first two-dimensional array detector 3, i.e., the coordinates in the real image space, u0, v0 represent the coordinates of the detection plane of the second two-dimensional array detector 5, i.e., the coordinates in the spatial Fourier frequency domain, and the function values ​​of f(x0, y0) and F(u0, v0) are the magnitudes of the light intensities (i.e., the squares of the light amplitudes) detected by the first two-dimensional array detector 3 and the second two-dimensional array detector 5, respectively.

[0039] The first two-dimensional array detector 3 and the second two-dimensional array detector 5 may employ a high sampling rate CCD, EMCCD, CMOS or sCMOS.

[0040] In this embodiment, the first image plane 7 is formed by direct imaging of the imaging light, and the second image plane 8 is formed by imaging the imaging light after it is reflected by the beam splitter 2. The first two-dimensional array detector 3 and the second two-dimensional array detector 5 use two different two-dimensional array detectors, and obtain image plane intensity information and spatial Fourier spectrum intensity information, respectively, through the two two-dimensional array detectors.

[0041] In another embodiment, one of the first image plane 7 and the second image plane 8 is formed by direct imaging of the imaging light, and the other is formed by imaging the imaging light after it is reflected by the beam splitter 2, and the first image plane 7 and the second image plane 8 are image planes representing the same information but at different positions. The imaging light at the second image plane 8 forms a spatial Fourier spectrum plane after being transformed by the Fourier transform lens 4. The first two-dimensional array detector 3 and the second two-dimensional array detector 5 can be the same two-dimensional array detector that can be moved to different optical paths, i.e., by moving the position of the same two-dimensional array detector, the first two-dimensional array detector 3 and the second two-dimensional array detector 5 can be used successively to obtain image plane intensity information when used as the first two-dimensional array detector 3, and obtain spatial Fourier spectrum intensity information when used as the second two-dimensional array detector 5.

[0042] In another embodiment, the beam splitter 2 can be arranged before the imaging component 1, i.e., the number of the beam splitter 2 is one and the number of the imaging components 1 is two. After the illumination light from the object to be measured passes through the beam splitter and is split into two illumination lights, the first individual imaging component receives one of the illumination lights and provides corresponding imaging light, which is imaged on the detection surface of the first two-dimensional array detector to form a first image plane; the second individual imaging component receives another illumination light and provides corresponding imaging light, which is imaged at a position at a known distance in front of the Fourier transform lens to form a second image plane, and forms a spatial Fourier spectrum plane on the detection surface of the second two-dimensional array detector on the focal plane after the Fourier transform lens. In this case, the first image plane is formed by direct imaging of the imaging light, and the second image plane is formed by imaging the imaging light after it is reflected by the beam splitter, and the first image plane and the second image plane are image planes that represent the same information but are located at different positions, and the imaging light at the second image plane satisfies the following condition: it forms a spatial Fourier spectrum plane after being transformed by a Fourier transform lens.

[0043] In another embodiment, the beam splitter 2 can be omitted, i.e., both the first image plane and the second image plane are formed by direct imaging of the imaging light and are the same image plane at the same position, and the first two-dimensional array detector and the second two-dimensional array detector can be two different two-dimensional array detectors that can be moved in and out of the optical path, or can be the same two-dimensional array detector that can be moved along the optical path, and when such a beam splitter is omitted, the Fourier transform lens is movable (i.e., can be moved in and out of the optical path), thereby switching between the image plane intensity information collection system and the spatial Fourier spectrum intensity information collection system through the import optical paths and export optical paths of different two-dimensional array detectors, or movement back and forth along the optical path of the same two-dimensional array detector, and the import optical path and export optical path of the Fourier transform lens.

[0044] The imaging component 1 includes, but is not limited to, an imaging lens component corresponding to a microscope objective lens outside a full-field imaging camera, a photographic lens component, and a telescope and remote sensing imaging lens component, etc.

[0045] The beam splitter 2 includes, but is not limited to, a 1:1 optical beam splitter and other optical beam splitters with fixed beam ratios.

[0046] The Fourier transform lens 4 can be an achromatic compound lens within the detection spectrum range, or an achromatic concave mirror or ellipsoidal mirror. The aperture D of the Fourier transform lens 4 does not cut off the spatial spectrum contained in the image, and its focal length f satisfies the sampling requirements of the image plane and the spatial Fourier spectrum intensity information plane, i.e., f = Δx1Δx2N / λ, where λ is the wavelength of the illumination light, Δx1 is the sampling interval of the first two-dimensional array detector 3, Δx2 is the sampling interval of the second two-dimensional array detector 5, and N is the number of sampling points.

[0047] The arithmetic processor 6 can be a computer or a built-in Fourier iterative processor or the like.

[0048] The calculation processor 6 is configured to receive the image plane intensity information and the spatial Fourier spectrum intensity information and to perform the following step S1.

[0049] The image plane intensity information and the spatial Fourier spectrum intensity information are used as constraints for the Fourier iteration operation, and amplitude spatial distribution information and phase spatial distribution information of the object to be measured are obtained by multiple Fourier iteration operations, thereby realizing total optical field imaging.

[0050] Therefore, based on the existing technology of restoring the phase through Fourier iteration, the present invention uses the optical path structures of the image plane intensity information collection system and the spatial Fourier spectrum intensity information collection system to simultaneously provide image plane intensity information and spatial Fourier spectrum intensity information, thereby realizing a full optical field camera.

[0051] The imaging result of the total optical field imaging is the amplitude spatial distribution information and phase spatial distribution information of the object to be measured obtained by the iterative Fourier calculation, which can be expressed as a wave function or as an image obtained by reconstruction including grayscale values, and the amplitude spatial distribution and phase spatial distribution are reflected in the image obtained by reconstruction as grayscale values ​​of each pixel grid on the image.

[0052] Here, the Fourier iterative calculation method includes, but is not limited to, several Fourier iterative phase recovery algorithms, such as 1. Gerchberg-Saxton (GS) algorithm, 2. Hybrid input-output (HIO) algorithm, and 3. Yang-Gu (YG) algorithm. Specifically, see the literature [Gerchberg RW, O. ASW. A practical algorithm for the determination of phase from image and diffraction plane pictures[J]. Optik, 1972, 35:237-250], [Fienup JR. Reconstruction of an object from modulus of its Fourier transform[J]. Optics Letters, 1978, 3(1):27-29], [Guozhen Yang, Benyuan Gu. Amplitude and phase recovery problem in optical systems[J]. Acta Physica Sinica, 1981, 30(3):410-413].

[0053] Correspondingly, the types of constraints for the Fourier iteration include, but are not limited to, intensity constraints, non-negativity constraints, spatial boundary constraints, and so on.

[0054] Hereinafter, the specific steps of step S1 will be described in detail using the Gerchberg-Saxton (GS) algorithm and strength constraints as an example.

[0055] Specifically, step S1 includes performing the following iterative calculation according to the detected image plane intensity information f(x0, y0) and spatial Fourier spectrum intensity information F(u0, v0).

[0056] Step S11: Initialize the current iteration round number k to 0, and calculate the image plane phase value φ of the iteration round number 0 for the detected image plane intensity distribution f(x0, y0). (0) Randomly assign the multiple forms f(x0,y0)e of the image plane intensity distribution of the current iteration round iφ(0) Get.

[0057] Step S12: Multiple forms f(x0, y0)e of the image plane intensity distribution of the current iteration round number iφ(k) Performs a Fourier transform on the spatial Fourier spectral transform result F for the current iteration round. (k) (u0,v0)e iΦ(k) where Φ (k) is the spectral transformation result of the image plane phase value of the current iteration round number.

[0058] Step S13: The spatial Fourier spectrum transform result F(u0, v0) is calculated using the detected spatial Fourier spectrum intensity information F(u0, v0). (k) (u0,v0)e iΦ(k) By replacing the base part of the spatial Fourier spectrum distribution of the current iteration round number, the plural form F(u0,v0)e iΦ(k) Get.

[0059] Step S14: Multiple forms F(u0, v0)e of the spatial Fourier spectrum distribution of the current iteration round number iΦ(k), and the image plane intensity distribution transformation result f (k) (x0,y0)e iφ(k) Get.

[0060] Step S15: The detected image plane intensity information f(x0, y0) is converted into the image plane intensity distribution transformation result f(x0, y0) of the next step of the current iteration round. (k) (x0,y0)e iφ(k+1) By replacing the base part of the current iteration round number with the next stage of the image plane intensity distribution, the plural form f(x0, y0)e iφ(k+1) Get.

[0061] Step S16: The next step k+1 of the current iteration round number is taken as the new current iteration round number k, and steps S12 to S15 are repeated until the algorithm converges. In this case, the multiple forms f(x0, y0)e of the image plane intensity distribution of the next round of the current iteration round are calculated. iφ(k+1) and the spatial Fourier spectrum distribution of the current iteration round number, F(u0,v0)e iΦ(k) is the complex amplitude f(x0,y0)e of the final reconstructed real image plane. iφ and the complex amplitude F(u0,v0)e of the spatial Fourier spectrum intensity information plane iΦ Get.

[0062] Here, after the kth iteration, the current iteration round number k and the multi-modal distribution of the spatial Fourier spectrum of the previous stage are expressed by the formula |F (k) (u0,v0)|=|F (k-1) If (u0,v0)| is satisfied, the algorithm is considered to have converged.

[0063] Step S17: The complex amplitude f(x0, y0)e of the finally reconstructed real image plane iφ and the complex amplitude F(u0,v0)e of the spatial Fourier spectrum intensity information plane iΦ According to the above, amplitude spatial distribution information and phase spatial distribution information of the object to be measured are determined.

[0064] Therefore, in this embodiment, in step S13, the present invention uses the intensity of the detected spatial Fourier spectrum plane as the constraint condition, and in step S15, the intensity of the detected real image plane is used as the intensity constraint condition, and the intensity information of the two planes is used as the intensity constraint condition to make the calculation result approximate the condition of the image constraint, so that the result satisfies the intensity constraints of both the real image plane and the spatial Fourier spectrum intensity information plane, and the missing phase information can be reliably calculated.

[0065] The above steps S11 to S16 provided by the present invention are based on the following operation principle.

[0066] In step S1, the two-dimensional array detector obtains the spatial Fourier spectrum intensity information on the spatial Fourier spectrum intensity information plane of the target object to be measured according to the sampling theorem, and the following equation can be obtained according to the sampling theorem:

[0067] TIFF0007812923000001.tif24110

[0068] Here, u and v represent the coordinates of the spatial Fourier spectrum intensity information plane, Φ represents the phase information of the light wave on the spatial Fourier spectrum intensity information plane, and L x ,L y represents the size of the real image plane area extending in the x and y directions, n and m represent each pixel grid position of sampling, and the sinc function is the Fourier transform of an orthogonal function.

[0069] In step S2, the two-dimensional array detector obtains the image plane intensity information of the object to be measured according to the sampling theorem, and the following equation can be obtained according to the sampling theorem:

[0070] TIFF0007812923000002.tif22120

[0071] Here, x and y represent the coordinates of the real image plane, φ represents the phase information of the light wave on the real image plane, and B x ,By represents the highest frequency of the object to be measured extending in the x and y directions, n and m represent each pixel grid position of sampling, and the sinc function is the Fourier transform of an orthogonal function.

[0072] Both can be combined by Fourier transform, and the complex amplitude f(x0, y0)e of the real image plane can be calculated by solving the above two equations through steps S11 to S16 using this intensity information as a known constraint. iφ and the complex amplitude F(u0,v0)e of the spatial Fourier spectrum intensity information plane iΦ , that is, unknown phase information φ and Φ can be obtained.

[0073] Second Example: Imaging method of the all-optical field imaging camera

[0074] The imaging method of the all-optical field imaging camera realized based on the above all-optical field imaging camera specifically includes the following steps:

[0075] Step S1': Provide an imaging component 1 so that illumination light illuminates the object to be measured and then passes through the imaging component 1 to form imaging light of the object to be measured, and either position the detection surface of a first two-dimensional array detector 3 at a first image plane 7 formed by the imaging light, or position a Fourier transform lens 4 at a position at a known distance from a second image plane 8 (for example, the Fourier transform lens 4 can be positioned so that its front focal plane is located at the second image plane 8 formed by the imaging light, i.e., so that the distance between the Fourier transform lens 4 and the second image plane 8 is equal to the focal length of the Fourier transform lens 4), and position a second two-dimensional array detector 5 at a rear focal plane of the Fourier transform lens 4, and collect image plane intensity information and spatial Fourier spectrum intensity information of the object to be measured using the first two-dimensional array detector 3 and the second two-dimensional array detector 5.

[0076] In this embodiment, step S1' includes a step in which the number of the imaging component 1 is one, a beam splitter 2 is disposed between the imaging component 1 and the first two-dimensional array detector 3, and a first image plane 7 is formed by direct imaging of the imaging light, and a second image plane 8 is formed by imaging the imaging light after it is reflected by the beam splitter 2, where the first image plane 7 and the second image plane 8 are image planes representing the same information but located at different positions, and the imaging light at the second image plane 8 forms a spatial Fourier spectrum plane after being transformed by a Fourier transform lens.

[0077] In another embodiment, step S1' includes a step in which the number of the imaging components 1 is two, and a beam splitter 2 is installed in front of the two imaging components 1, so that after the illumination light from the object to be measured passes through the beam splitter and is split into two illumination lights, a first individual imaging component receives one of the illumination lights and provides corresponding imaging light, which is imaged on a detection surface of a first two-dimensional array detector to form a first image plane; a second individual imaging component receives another illumination light and provides corresponding imaging light, which is imaged at a position at a known distance in front of a Fourier transform lens to form a second image plane, and a spatial Fourier spectrum plane is formed on the detection surface of a second two-dimensional array detector on a focal plane after the Fourier transform lens. In this case, a first image plane is formed by direct imaging of the imaging light, and a second image plane is formed by imaging the imaging light after it is reflected by the beam splitter, the first image plane and the second image plane are image planes representing the same information but at different positions, and the imaging light at the second image plane forms a spatial Fourier spectrum plane after being transformed by a Fourier transform lens.

[0078] In another embodiment, the beam splitter 2 can be omitted, i.e., both the first image plane and the second image plane are formed by direct imaging of the imaging light and are the same image plane at the same position, and the first two-dimensional array detector and the second two-dimensional array detector may be two-dimensional array detectors with two different optical paths that can be moved in and out of the optical path, or may be the same two-dimensional array detector that can be moved along the optical path, and when such a beam splitter is omitted, the Fourier transform lens is movable (i.e., can be moved in and out of the optical path), thereby switching between the image plane intensity information collection system and the spatial Fourier spectrum intensity information collection system through the import optical paths and export optical paths of different two-dimensional array detectors, or movement back and forth along the optical path of the same two-dimensional array detector, and the import optical path and export optical path of the Fourier transform lens.

[0079] Step S2': The image plane intensity information and spatial Fourier spectrum intensity information of the object to be measured acquired in step S1' are uploaded to the calculation processor 6, and the calculation processor 6 is used to execute the following steps: the image plane intensity information and spatial Fourier spectrum intensity information are used as constraints for the Fourier iteration calculation, and amplitude spatial distribution information and phase spatial distribution information of the object to be measured are acquired through multiple Fourier iteration calculations, thereby realizing full optical field imaging.

[0080] The specific content of step S1 is as described above.

[0081] Third embodiment: A total optical field imaging device based on a total optical field imaging camera

[0082] As shown in Fig. 2, a total optical field imaging device based on a total optical field imaging camera according to a third embodiment of the present invention is used to realize total optical field imaging of ground glass using a total optical field imaging camera. As shown in Fig. 2, the total optical field imaging device includes a laser 10, a first converging lens 20, an object 30 to be measured, a magnifying objective lens 40, and the above-mentioned total optical field imaging camera 50, which are sequentially arranged on the same optical axis. The first converging lens 20 and the magnifying objective lens 40 constitute an imaging lens group, and the first converging lens 20 and the magnifying objective lens 40 are respectively the imaging lens and the imaging objective lens of the imaging lens group. The object 30 to be measured is positioned on the focal plane of the magnifying objective lens 40.

[0083] Thus, the laser light emitted by the laser 10 is focused by the first focusing lens 20 before being irradiated onto the target object 30 to be measured, and then magnified by the objective lens 4 to meet the sampling requirements of the detector. Here, the imaging component 1 of the full-field imaging camera 50 is combined with the magnifying objective lens 40 to meet the imaging requirements of the full-field imaging camera 50, obtain the amplitude and phase information of the ground glass sample, and realize full-field imaging to obtain the surface morphology of the ground glass.

[0084] The object 30 to be measured is a transparent object, and in this embodiment, the object 30 to be measured is ground glass.

[0085] In this embodiment, the wavelength of the laser light emitted by the laser 10 is 532 nm.

[0086] In this embodiment, the distance between the first convergent lens 20 and the target object 30 to be measured is the focal length of the convergent lens 20, and the focal length of the first convergent lens 20 may be 50 mm.

[0087] In this embodiment, the magnification objective lens 40 has a magnification of 10 and a NA of 0.1.

[0088] In this embodiment, the imaging component 1 in the all-optical-field imaging camera 50 is an imaging lens, and the focal length of the imaging lens, in combination with the magnifying objective lens 40, satisfies the condition: focal length of the imaging lens = equivalent focal length of the magnifying objective lens × magnification factor. In this embodiment, the focal length of the imaging component 1 is 180 mm.

[0089] In this embodiment, the focal length of the Fourier transform lens 4 in the all-optical-field imaging camera 50 can be 100 mm.

[0090] In this embodiment, all the two-dimensional array detectors in the all-optical-field imaging camera 5 can use 2048×2048 CMOS array detectors, and the pixel size is 6.45μm×6.45μm. In another embodiment, in order to satisfy the calculation formula of the sampling theorem 2NA / λ < Mag / 2Δx, the pixel size can be any value less than or equal to 13.3um, where NA is the numerical aperture of the lens, λ is the wavelength of the illumination light, Mag is the magnification factor of the lens, and Δx is the sampling size that must be larger than the pixel size. Also, the sampling of the two-dimensional array detector must satisfy the sampling theorem in the frequency domain, that is, Δx f =λf / S, where Δx f is the size of the sampling interval, specifically, the size of each pixel grid of the detector, λ is the wavelength of the illumination light, f is the focal length of the lens, and S is the size of the image plane area.

[0091] In this embodiment, the effect of magnification using the magnifying objective lens 40 is that, based on the sampling theorem, the sampling frequency must be greater than twice the highest frequency in the signal so that the digital signal after sampling can completely retain the information in the original signal. Therefore, in order to make the sampling more complete and more appropriately restore the phase information of the ground glass, it is necessary to magnify the ground glass.

[0092] Compared with conventional methods for measuring the rough surface of ground glass, such as contact probe detection and interferometry detection, the total optical field imaging device based on the total optical field imaging camera of the present invention has the advantages of not contacting the sample and simplifying the realization of the optical path. Furthermore, compared with existing Fourier transform optical lithography or coherent diffraction imaging technologies, the spatial Fourier spectrum information does not need to have overlapping portions or obtain sufficient information to restore the phase through oversampling. By obtaining sufficient information through double-sided imaging, redundant information can be reduced, reducing the required data and easing the difficulty of experimental operations.

[0093] Fourth embodiment: A total optical field imaging device based on a total optical field imaging camera

[0094] As shown in FIG. 3, a fourth embodiment of the present invention provides a total optical field imaging device based on a total optical field imaging camera, which is applied to imaging in the field of microscopy. As shown in FIG. 3, the total optical field imaging device based on the total optical field imaging camera includes a laser 10', a beam splitter 20', an objective lens 30', an object 40' to be measured, which are arranged on the same optical axis, and a total optical field imaging camera 50' aligned with the beam splitter 20' and arranged on another optical axis. In this embodiment, the objective lens 30' constitutes one imaging objective lens in an imaging lens group, and the imaging lens group has only one imaging lens. The object 40' to be measured is located on the focal plane of the objective lens 30'.

[0095] As a result, the laser light is focused on the target object 40' to be measured through the objective lens 30', and the scattered light generated by the sample is collected and imaged by the objective lens 30' into the above-mentioned full-field imaging camera 50' to obtain the amplitude and phase information of the sample, thereby realizing full-field imaging of the microscope object sample.

[0096] In this embodiment, the wavelength of the laser light emitted by the laser 10' is 532 nm.

[0097] In this embodiment, the objective lens 30' has a magnification of 100 times and a numerical aperture of 0.8.

[0098] In this embodiment, the imaging component 1 in the all-optical-field imaging camera 50' is an imaging lens, and the focal length of the imaging lens satisfies the condition that when combined with the magnifying objective lens 40, the focal length of the imaging lens = the equivalent focal length of the magnifying objective lens × the magnification factor. In this embodiment, the focal length of the imaging component 1 is 180 mm.

[0099] In this embodiment, the focal length of the Fourier transform lens 4 in the all-optical-field imaging camera 50' can be 100 mm.

[0100] In this embodiment, all the two-dimensional array detectors in the all-optical-field imaging camera 5 can use 2048×2048 CMOS array detectors, and the pixel size is 6.45 μm×6.45 μm. In another embodiment, in order to satisfy the calculation formula of the sampling theorem 2NA / λ < Mag / 2Δx, the pixel size can be any value less than or equal to 13.3 um, where NA is the numerical aperture of the lens, λ is the wavelength of the illumination light, Mag is the lens magnification factor, and Δx is the sampling size that must be larger than the pixel size. Also, the sampling of the two-dimensional array detector needs to satisfy the sampling theorem in the frequency domain, that is, Δx f =λf / S, where Δx f is the size of the sampling interval, specifically, the size of each pixel grid of the detector, λ is the wavelength of the illumination light, f is the focal length of the lens, and S is the size of the image plane area.

[0101] In another embodiment, the all-optical field imaging device based on the all-optical field imaging camera may be a microscope, a camera, or a remote sensing device including a telescope and the above-mentioned all-optical field imaging camera, wherein the imaging components of the all-optical field imaging camera include an imaging lens component corresponding to the microscope objective lens, a photographic lens component corresponding to the camera, or a telescope and a remote sensing imaging component corresponding to the telescope and the remote sensing device.

[0102] Compared with existing Fourier optics imaging technology or coherent diffraction imaging technology, the microscopic imaging realized by the all-optical field imaging device based on the all-optical field imaging camera of the present invention does not require the spatial Fourier spectrum information to have overlapping portions or to obtain sufficient information to restore the phase by oversampling, but rather obtains sufficient information by double-sided imaging, thereby reducing redundant information, reducing the required data, and easing the difficulty of experimental operations.

[0103] The above is merely a preferred embodiment of the present invention, and does not limit the scope of the present invention, and various modifications are possible to the above-mentioned embodiment of the present invention. All simple and equivalent changes and modifications made based on the claims and the contents of the specification of the present invention are included in the scope of protection of the claims of the present invention. Everything not described in detail in the present invention is conventional technology.

Claims

1. It is a full-field imaging camera, the imaging component and the first two-dimensional array detector are sequentially arranged along the direction of the optical path to form an image plane intensity information collection system; the imaging component, the Fourier transform lens, and the second two-dimensional array detector are sequentially arranged along the direction of the optical path to form a spatial Fourier spectrum intensity information collection system; and an arithmetic processor communicatively connected to the first two-dimensional array detector and the second two-dimensional array detector, wherein the imaging component is configured to receive illumination light from an object to be measured and provide imaging light of the object to be measured, the imaging light being imaged onto a detection surface of the first two-dimensional array detector to form a first image plane, the imaging light being imaged at a position at a known distance in front of the Fourier transform lens to form a second image plane, and forming a spatial Fourier spectrum plane on a detection surface of the second two-dimensional array detector on a focal plane after the Fourier transform lens; the imaging light at the second image plane forms a spatial Fourier spectrum plane after being transformed by a Fourier transform lens; the calculation processor is configured to receive the image plane intensity information and the spatial Fourier spectrum intensity information, and perform a step S1 of acquiring amplitude spatial distribution information and phase spatial distribution information of the object to be measured through a plurality of Fourier iterations using the image plane intensity information and the spatial Fourier spectrum intensity information as constraints for the Fourier iterations, thereby realizing total optical field imaging, wherein the Fourier iterations include a Gerchberg-Saxton algorithm, a hybrid input-output algorithm, or a Yang-Gu algorithm.

2. The number of the imaging components is one, and a beam splitter is installed between the imaging component and the Fourier transform lens, or the number of the imaging components is two, and a beam splitter is installed in front of the two imaging components; and one of the first and second image planes is formed by direct imaging of the imaging light, and the other is formed by imaging the imaging light after it is reflected by the beam splitter, and the first and second image planes are image planes at different positions that represent the same information. The all-light field imaging camera of claim 1 .

3. The first two-dimensional array detector and the second two-dimensional array detector are two different two-dimensional array detectors that simultaneously detect the first image plane intensity information and the spatial Fourier spectrum plane intensity information, respectively, or are the same two-dimensional array detector that can be moved along the optical path, and the Fourier transform lens is movable, and switching between an image plane intensity information collection system and a spatial Fourier spectrum intensity information collection system is performed by moving the two-dimensional array detector and moving the Fourier transform lens into and out of the optical path. The all-light field imaging camera of claim 1 .

4. The imaging light at the second image plane is imaged on a focal plane in front of a Fourier transform lens. The all-light field imaging camera of claim 1 .

5. 1. A method of imaging with a total light field imaging camera, comprising: providing an imaging component so that illumination light illuminates an object to be measured and then passes through the imaging component to form imaging light of the object to be measured; arranging a detection surface of a first two-dimensional array detector at a first image plane formed by imaging the imaging light; arranging a Fourier transform lens at a position at a known distance from the second image plane; arranging a second two-dimensional array detector at a focal plane after the Fourier transform lens; and collecting and acquiring image plane intensity information and spatial Fourier spectrum intensity information of the object to be measured by the first two-dimensional array detector and the second two-dimensional array detector; and a step S2' of uploading the image plane intensity information and the spatial Fourier spectrum intensity information of the object to be measured, which are acquired in step S1', to a calculation processor, and using the calculation processor to perform a plurality of Fourier iterations using the image plane intensity information and the spatial Fourier spectrum intensity information as constraints for the Fourier iterations to acquire amplitude spatial distribution information and phase spatial distribution information of the object to be measured, thereby performing step S1 to realize total optical field imaging; The imaging method of the all-optical field imaging camera, wherein the imaging light at the second image plane forms a spatial Fourier spectrum plane after being transformed by a Fourier transform lens.

6. 6. The imaging method for a total light field imaging camera according to claim 5, wherein step S1' further includes a step in which the number of the imaging components is one and a beam splitter is disposed between the imaging component and the first two-dimensional array detector, or the number of the imaging components is two and a beam splitter is disposed in front of the two imaging components, whereby a first image plane is formed by direct imaging of the imaging light and a second image plane is formed by imaging the imaging light after it is reflected by the beam splitter.

7. The illumination light is coherent light or partially coherent light with a known degree of coherence, and the partially coherent light satisfies the criterion of quasi-monochromaticity. The imaging method for a full-light-field imaging camera according to claim 5 .

8. 1. A total light field imaging device based on a total light field imaging camera, comprising:

10. An all-optical field imaging device based on the all-optical field imaging camera, comprising: a laser, an object to be measured, and an imaging lens group on the same optical axis; and the all-optical field imaging camera according to any one of claims 1 to 4, wherein the imaging lens group is one imaging objective lens, or one imaging objective lens and one imaging lens, and the object to be measured is located on the focal plane of the imaging objective lens of the imaging lens group.

9. A total optical field imaging camera as described in any one of claims 1 to 4, characterized in that the total optical field imaging camera is a microscope, a camera, or a telescope and remote sensing device, and the imaging components of the total optical field imaging camera include an imaging lens component corresponding to the objective lens of the microscope, a photographic lens component corresponding to the camera, or a telescope and remote sensing imaging component corresponding to the telescope and remote sensing device.

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