Flat plate objective based reflection confocal scanning microscope

Abstract

The application provides a flat plate objective based reflection confocal scanning microscope, comprising: a first beam splitter, which is suitable for splitting a light signal; a flat plate objective, which is integrated in the reflection confocal scanning microscope as a focusing mirror and a collection mirror, and is suitable for forming an ultra-diffraction limit focal spot on the incident light signal passing through the first beam splitter and collecting a reflected light signal reflected by a detected sample; an electric displacement table, which is suitable for carrying the detected sample and controlling the movement of the detected sample; a second beam splitter, which is suitable for performing a second splitting process on the reflected light signal passing through the first beam splitter; a first lens, which is suitable for focusing the reflected light signal passing through the second beam splitter; an aperture stop, which is arranged at the focal plane of the first lens and is suitable for performing an out-of-focus light filtering process on the reflected light signal passing through the first lens; and a first photodetector, which is suitable for detecting the reflected light signal passing through the aperture stop.

Description

Technical Field

[0001] This invention relates to the fields of micro-nano optics and far-field label-free super-resolution microscopy, specifically to a reflective confocal scanning microscope based on a flat objective lens. Background Technology

[0002] Due to the Abbe diffraction limit, the resolution of traditional optical microscopes is limited to λ / 2 (λ is the working wavelength). As a far-field super-resolution imaging technique, confocal scanning microscopy has been widely used in fields such as biological imaging and semiconductors. Traditional confocal scanning microscopes include two working modes: transmission and reflection. Both working modes involve the use of high numerical aperture and large-volume traditional objectives; however, their working distance is often only a few hundred micrometers, which is not conducive to the placement and detection of complex samples.

[0003] In recent years, planar diffractive lenses, such as superoscillating lenses and supercritical lenses, have attracted widespread interest due to their excellent focusing performance and their miniaturization and customizability. Planar diffractive lenses with sub-diffraction-limited focal spots can be integrated as condenser lenses in traditional transmission confocal scanning microscopes to further improve imaging resolution, but their working distance is not improved compared to traditional confocal scanning microscopes; and because of the low focusing efficiency and poor wide-field imaging capability of planar diffractive lenses, they cannot be used simultaneously as collecting lenses in reflection confocal scanning microscopes. Summary of the Invention

[0004] In view of the above problems, the present invention provides a reflective confocal scanning microscope based on a flat plate objective lens, which integrates a novel flat plate objective lens as both a focusing lens and a collecting lens into the aforementioned reflective confocal scanning microscope, and rationally configures the spatial relative positions of each optical element.

[0005] One aspect of the present invention provides a reflective confocal scanning microscope based on a flat plate objective, comprising: a first beam splitter adapted to split an optical signal, wherein the optical signal includes an incident light signal and a reflected light signal reflected by a sample being tested; a flat plate objective, integrated in the reflective confocal scanning microscope as both a focusing lens and a collecting lens, adapted to form a super-diffraction-limited focal spot on the incident light signal transmitted through the first beam splitter and to collect the reflected light signal reflected by the sample being tested; an electric stage adapted to carry the sample being tested and to control the movement of the sample being tested; a second beam splitter adapted to perform a second beam splitting process on the reflected light signal passed through the first beam splitter; a first lens adapted to focus the reflected light signal transmitted through the second beam splitter; an aperture stop configured at the focal plane of the first lens, adapted to filter out defocused light from the reflected light signal passed through the first lens; and a first photodetector adapted to detect the reflected light signal passing through the aperture stop.

[0006] According to an embodiment of the present invention, the first beam splitter and the second beam splitter have the same structure, both being semi-transmissive and semi-reflective mirrors; the placement direction of the first beam splitter is the same as that of the second beam splitter; the second beam splitter is configured to be placed at an acute angle to the first lens to ensure that only the reflected light signal after being reflected by the first beam splitter passes through the second beam splitter.

[0007] According to an embodiment of the present invention, the diameter of the aperture stop is between 10 nm and 5 mm.

[0008] According to an embodiment of the present invention, the reflection confocal scanning microscope based on a flat objective lens further includes:

[0009] The second lens is used to focus the reflected light signal reflected by the second beam splitter; the second photodetector is used to detect the reflected light signal passing through the second lens; the control device is connected to the electric displacement stage, the first photodetector and the second photodetector, and is used to control the movement of the electric displacement stage and the signal detection of the first photodetector and the second photodetector.

[0010] According to an embodiment of the present invention, the above-mentioned electric displacement stage includes one of an electric two-dimensional displacement stage and an electric three-dimensional displacement stage; wherein the above-mentioned electric two-dimensional displacement stage and electric three-dimensional displacement stage include one of a piezoelectric displacement stage, a DC servo motor, a resonant motor and a stepper motor; the above-mentioned first photodetector includes a photomultiplier tube; the above-mentioned second photodetector includes one of a CCD camera and a CMOS camera.

[0011] According to an embodiment of the present invention, the above-mentioned flat objective lens is obtained by phase modulation using micro-nano structures; wherein, the micro-nano structures include either Fresnel ring structures or metasurfaces;

[0012] According to an embodiment of the present invention, the Fresnel ring structure is formed by etching ring grooves on a first dielectric substrate; the metasurface includes a second dielectric substrate and a dielectric nanostructure located on the second dielectric substrate, the dielectric nanostructure including a plurality of dielectric nanopillars; the thickness of the first dielectric substrate is less than 2 mm; the thickness of the second dielectric substrate is less than 2 mm; the etching position, etching width and etching depth of the grooves are determined by the refractive index of the dielectric substrate material, the working wavelength and the phase distribution of the flat objective lens.

[0013] According to an embodiment of the present invention, the first dielectric substrate and the second dielectric substrate are made of the same material, including: a quartz substrate, an alumina substrate, a glass substrate, and one of other dielectric substrates; the material of the dielectric nanopillars includes: one of TiO2, HfO2, ZrO2, GaN, Si2N3, Si, GaAs, ZnS, and AlN.

[0014] According to an embodiment of the present invention, the dielectric nanopillar includes one of rectangular nanopillar, elliptical nanopillar, cross-shaped nanopillar, and L-shaped nanopillar; wherein the height and width of the dielectric nanopillar are determined by the phase distribution of the flat objective lens, the dielectric nanopillar, and the operating wavelength.

[0015] According to embodiments of the present invention, by integrating a flat objective obtained by phase modulation using micro-nano structures as both a focusing lens and a collecting lens into the aforementioned reflective confocal scanning microscope, and by rationally configuring the spatial relative positions of each optical element, the novel reflective confocal scanning microscope has higher resolution, a longer working distance, providing more operational space for sample placement and detection, and a more compact structure compared to traditional confocal microscopes. Attached Figure Description

[0016] The above-described features, other objects, and advantages of the present invention will become clearer from the following description of embodiments of the invention with reference to the accompanying drawings, in which:

[0017] Figure 1 This is a schematic diagram of a reflective confocal scanning microscope based on a flat objective lens according to an embodiment of the present invention;

[0018] Figure 2 This is a schematic diagram of the resolution test results of a reflective confocal scanning microscope based on a flat objective lens according to an embodiment of the present invention;

[0019] Figure 3 This is a schematic diagram of scanning imaging of complex patterns using a reflective confocal scanning microscope based on a flat objective lens according to an embodiment of the present invention.

[0020] Explanation of reference numerals in the attached figures:

[0021] 1: First beam splitter;

[0022] 2: Flat objective lens;

[0023] 3: Test samples

[0024] 4: Electric displacement stage;

[0025] 5: Second beam splitter;

[0026] 6: First lens;

[0027] 7: Aperture stop;

[0028] 8: First photodetector;

[0029] 9: Second lens;

[0030] 10: Second photodetector;

[0031] 11: Control device. Detailed Implementation

[0032] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the invention. In the following detailed description, numerous specific details are set forth to provide a thorough understanding of the embodiments of the invention for ease of explanation. However, it will be apparent that one or more embodiments may be practiced without these specific details. Furthermore, descriptions of well-known structures and techniques are omitted in the following description to avoid unnecessarily obscuring the concept of the invention.

[0033] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention. The terms “comprising,” “including,” etc., as used herein indicate the presence of the stated features, steps, operations, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, or components.

[0034] All terms used herein (including technical and scientific terms) have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein are to be interpreted in a manner consistent with the context of this specification, and not in an idealized or overly rigid way.

[0035] When using expressions such as "at least one of A, B, and C", they should generally be interpreted in accordance with the meaning that is commonly understood by a person skilled in the art (e.g., "a system having at least one of A, B, and C" should include, but is not limited to, a system having A alone, a system having B alone, a system having C alone, a system having A and B, a system having A and C, a system having B and C, and / or a system having A, B, and C, etc.).

[0036] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0037] Unlike traditional objectives that use refraction to achieve diffraction-limited focal spots, flat diffractive lenses can achieve super-diffraction-limited focal spots through diffraction. Although flat diffractive lenses can also achieve super-diffraction-limited focusing and can be integrated as focusing lenses in transmission confocal scanning microscopes to improve imaging resolution, their low diffraction efficiency and poor wide-field imaging capabilities prevent them from being simultaneously integrated as collecting lenses in reflection confocal scanning microscopes. Therefore, reflection confocal microscopes based on flat objectives are of great significance in improving imaging resolution, increasing working distance, and achieving a more compact overall microscope structure.

[0038] Figure 1 This is a schematic diagram of a reflective confocal scanning microscope based on a flat objective lens according to an embodiment of the present invention.

[0039] According to an exemplary embodiment of the present invention, a reflection confocal scanning microscope based on a flat objective lens is disclosed. (Refer to...) Figure 1 As shown, the system includes: a first beam splitter 1, a flat objective lens 2, an electrically driven stage 4, a second beam splitter 5, a first lens 6, an aperture stop 7, and a first photodetector 8. The first beam splitter 1 is used to split the optical signal, which includes the incident light signal and the reflected light signal from the sample being tested. The flat objective lens 2, integrated as both a focusing lens and a collecting lens in the reflective confocal scanning microscope, is used to form a super-diffraction-limited focal spot on the incident light signal transmitted through the first beam splitter 1 and to collect the reflected light signal from the sample being tested. The electrically driven stage 4 is used to carry the sample and control its movement. The second beam splitter 5 is used to perform a second beam splitting process on the reflected light signal after passing through the first beam splitter 1. The first lens 6 is used to focus the reflected light signal transmitted through the second beam splitter 5. The aperture stop 7 is configured at the focal plane of the first lens 6 and is used to filter out defocused light from the reflected light signal after passing through the first lens 6. The first photodetector 8 is used to detect the reflected light signal passing through the aperture stop 7.

[0040] According to an embodiment of the present invention, by integrating the flat objective 2 obtained by phase modulation using micro-nano structures as both a focusing lens and a collecting lens into the above-mentioned reflective confocal scanning microscope, and by rationally configuring the spatial relative positions of each optical element, the novel reflective confocal scanning microscope has higher resolution, a longer working distance, providing more operating space for sample placement and detection, and a more compact structure compared to traditional confocal microscopes.

[0041] According to an embodiment of the present invention, the novel reflective confocal scanning microscope based on a flat objective lens can achieve the technical effects of a focal length greater than or equal to 0.5 mm, a focusing efficiency greater than 5%, and an imaging numerical aperture greater than 0.7.

[0042] According to an embodiment of the present invention, a reflective confocal scanning microscope based on a flat objective lens further includes: a second lens 9, adapted to focus the reflected light signal reflected by the second beam splitter 5; a second photodetector 10, adapted to detect the reflected light signal passing through the second lens 9; and a control device 11, which is simultaneously connected to the electric stage 4, the first photodetector 8, and the second photodetector 10, and is adapted to control the movement of the electric stage 4 and the signal detection of the first photodetector 8 and the second photodetector 10.

[0043] According to an embodiment of the present invention, the incident light signal first passes through the first beam splitter 1; the incident light signal passing through the first beam splitter 1 reaches the flat objective lens 2, and after being focused by the flat objective lens 2, the super-diffraction-limited focal spot irradiates the detection sample 3 placed on the electric displacement stage 4, thereby acquiring the imaging information of the detection sample 3. In this process, the detection sample 3 is placed at the focal plane of the flat objective lens 2 as much as possible, so the reflected light signal with an imaging numerical aperture of less than 0.83 is further collected by the flat objective lens 2.

[0044] According to an embodiment of the present invention, the reflected light signal collected by the flat objective lens 2 is further transmitted to the first beam splitter 1 for beam splitting. The reflected light signal is then split a second time by the second beam splitter 5. The reflected light signal reflected by the second beam splitter 5 reaches the second photodetector 10 through the second lens 9, thereby indirectly monitoring the relative position of the detection sample 3 and the flat objective lens 2.

[0045] According to an embodiment of the present invention, when the sample 3 is deviated from the focal plane of the flat objective lens 2, the reflected light signal from the sample 3 cannot be detected on the second photodetector 10; then the electric displacement stage 4 is adjusted in the vertical direction so that the sample 3 is close to the focal plane of the flat objective lens 2, thereby ensuring that the reflected light signal from the sample 3 is detected on the second photodetector 10.

[0046] According to an embodiment of the present invention, the reflected light signal passing through the second beam splitter 5 is focused by the first lens 6 to the aperture stop 7 located at the focal plane of the first lens 6, thereby filtering out defocused light from the reflected light signal. Subsequently, the defocused reflected light signal reaches the first photodetector 8. At this time, based on the intensity of the reflected light signal detected by the first photodetector 8, the electric displacement stage 4 is finely adjusted in the vertical direction to ensure that the maximum value of the reflected light signal intensity of the sample 3 being tested is collected and recorded by the first photodetector 8.

[0047] According to an embodiment of the present invention, the first beam splitter 1 and the second beam splitter 5 have the same structure, both being semi-transmissive and semi-reflective mirrors; the placement direction of the first beam splitter 1 is the same as the placement direction of the second beam splitter 5; the second beam splitter 5 is configured to be placed at an acute angle to the first lens 6 to ensure that only the reflected light signal after being reflected by the first beam splitter 1 passes through the second beam splitter 5.

[0048] According to an embodiment of the present invention, the diameter of the aperture stop 7 is between 10 nm and 5 mm, thereby defocusing the reflected light signal transmitted through the first lens 6, so that the first photodetector 8 only collects the intensity of the reflected light signal from the confocal surface.

[0049] According to an embodiment of the present invention, the movement of the motorized stage 4, the recording of the intensity of the reflected light signal collected by the first photodetector 8 and the second photodetector 10 are controlled by the LabVIEW graphical programming language. During the scanning imaging process, the super-diffraction-limited focal spot of the flat objective lens 2 illuminates the test sample 3. The reflected light signal of the test sample 3 is collected by the flat objective lens 2, and then passes sequentially through the first beam splitter 1, the second beam splitter 5, the first lens 6, and the aperture stop 7 placed at the focal plane of the lens before being collected by the first photodetector 8. This information serves as the imaging information of the test sample 3 at that scanning point, thus completing one point-to-point scanning imaging. Afterwards, LabVIEW sends a horizontal movement command to the motorized stage 4, causing the motorized stage 4 to move horizontally to the next detection point for scanning. LabVIEW then records the intensity of the reflected light signal collected by the first photodetector 8 at that point on the test sample 3, until all test points of the entire test sample 3 have been scanned and imaged.

[0050] According to an embodiment of the present invention, the electric displacement stage 4 includes one of an electric two-dimensional displacement stage and an electric three-dimensional displacement stage; wherein the electric two-dimensional displacement stage and the electric three-dimensional displacement stage include one of a piezoelectric displacement stage, a DC servo motor, a resonant motor and a stepper motor; the first photodetector 8 includes a photomultiplier tube; the second photodetector 11 includes one of a CCD camera and a CMOS camera.

[0051] According to an embodiment of the present invention, the electric displacement stage 4 is first coarsely adjusted in the vertical direction based on the reflected light signal detected by the second photodetector 10, so that the sample 3 is approximately located at the focal plane of the flat objective lens 2; then, the electric displacement stage 4 is finely adjusted in the vertical direction based on the intensity of the reflected light signal detected by the first photodetector 8, so that the sample 3 is located at the focal plane of the flat objective lens 2, thereby ensuring that the first photodetector 8 records the maximum value of the intensity of the reflected light signal of the sample 3.

[0052] According to embodiments of the present invention, in order to eliminate background light, the reflective confocal scanning microscope based on a flat objective lens may further include:

[0053] The first linear polarizer is configured to be placed on the side of the first beam splitter 1 away from the flat objective lens 2;

[0054] The second linear polarizer is configured to be placed between the second beam splitter 5 and the first lens 6;

[0055] The third linear polarizer is configured to be placed between the second beam splitter 5 and the second lens 9;

[0056] A quarter-wave plate film is configured to be disposed on the surface of the flat objective lens 2 on the side closest to the sample 3 being tested.

[0057] According to an embodiment of the present invention, the flat objective lens 2 is obtained by phase modulation using micro-nano structures;

[0058] Among them, micro-nano structures include Fresnel ring structures and a type of metasurface;

[0059] According to an embodiment of the present invention, the Fresnel ring structure is formed by etching ring grooves on a first dielectric substrate; the metasurface includes a second dielectric substrate and a dielectric nanostructure located on the second dielectric substrate, the dielectric nanostructure including a plurality of dielectric nanopillars;

[0060] The thickness of the first dielectric substrate is less than 2 mm;

[0061] The thickness of the second dielectric substrate is less than 2 mm;

[0062] The etching location, etching width, and etching depth of the groove are determined by the refractive index of the dielectric substrate material, the working wavelength, and the phase distribution of the flat objective lens.

[0063] According to an embodiment of the present invention, the first dielectric substrate and the second dielectric substrate are made of the same material, including: a quartz substrate, an alumina substrate, a glass substrate, and one of other dielectric substrates;

[0064] The materials for dielectric nanopillars include one of the following: TiO2, HfO2, ZrO2, GaN, Si2N3, Si, GaAs, ZnS, and AlN.

[0065] According to embodiments of the present invention, the dielectric nanopillars include one of rectangular nanopillars, elliptical nanopillars, cross-shaped nanopillars, and L-shaped nanopillars;

[0066] The height and width of the dielectric nanopillars are determined by the phase distribution of the flat objective lens, the dielectric nanopillars, and the operating wavelength.

[0067] According to an embodiment of the present invention, since the novel flat objective 2 introduced has high focusing efficiency, and by reasonably configuring the relative positions of the beam splitter and the lens and the setting position of the aperture stop, the novel reflective confocal scanning microscope based on the flat objective can allow sufficient reflected light signals from the sample being tested.

[0068] According to an embodiment of the present invention, since the novel flat objective 2 introduced has good wide-field imaging capability, and by reasonably configuring the relative positions of the beam splitter and the lens, the reflected light signal reflected back from the sample being tested in the novel reflective confocal scanning microscope based on the flat objective can be collected by the flat objective 2.

[0069] Figure 2 This is a schematic diagram of the resolution test results of a reflective confocal scanning microscope based on a flat objective lens according to an embodiment of the present invention.

[0070] like Figure 2 As shown, Figure 2 Figure (a) in the image is a scanning electron microscope image; Figure 2 Figure (b) in the figure is a coherent bright-field microscope image; Figure 2 Figure (c) in the figure is a reflection confocal scanning microscope image based on a conventional objective lens; Figure 2 Figure (d) in the figure is a reflection confocal scanning microscope image based on the flat objective lens 2; Figure 2 Figure (e) shows the resolution test results of each microscope; in the figure, I, II, III, IV, V and VI represent the center distance of each microscope, I represents 190nm, II represents 200nm, III represents 220nm, IV represents 240nm, V represents 250nm and VI represents 270nm; 1 and 0 represent normalized intensity values.

[0071] like Figure 2 As shown, imaging was performed on double slits with a length of 2 μm, a linewidth of 50 nm, and center-to-center distances of 190 nm, 200 nm, 220 nm, 240 nm, 250 nm, and 270 nm. Comparison revealed that at a working wavelength of 405 nm, a coherent bright-field microscope with a numerical aperture of 0.9 using a conventional objective lens could not resolve any of the double slits; a confocal scanning microscope with a numerical aperture of 0.9 using a conventional objective lens could resolve a double slit with a center-to-center distance of 240 nm; however, the confocal scanning microscope based on the flat objective lens 2 in this application achieves a resolution of 200 nm. Therefore, the confocal scanning microscope based on the flat objective lens 2 in this application exhibits significantly higher imaging resolution.

[0072] Figure 3 This is a schematic diagram of scanning imaging of complex patterns using a reflective confocal scanning microscope based on a flat objective lens according to an embodiment of the present invention.

[0073] like Figure 3 As shown, Figure 3 Figure (a) in the image is a scanning electron microscope image; Figure 3 Figure (b) in the figure is a coherent bright-field microscope image; Figure 3 Figure (c) in the figure is a reflection confocal scanning microscope image based on a conventional objective lens; Figure 3 Figure (d) is a reflection confocal scanning microscope image based on the flat objective lens 2; in the figure, 1 and 0 represent normalized intensity values.

[0074] like Figure 3 As shown, the dolphin's overall dimensions are 8μm*8μm, with a linewidth of 50nm. Comparison revealed that the imaging results of a coherent bright-field microscope using a conventional objective lens with a numerical aperture of 0.9 are coarse, and pattern details (such as eye and tail lines) are indistinguishable; similarly, a confocal scanning microscope using a conventional objective lens with a numerical aperture of 0.9 also fails to resolve some details of the eyes and tail; however, the reflective confocal scanning microscope based on the flat objective lens 23 in this application can resolve tail details at 225nm, with much clearer pattern lines.

[0075] According to embodiments of the present invention, the reflective scanning confocal microscope based on the flat objective 2 has higher resolution, longer working distance, and more compact layout compared to the reflective scanning confocal microscope based on the conventional objective.

[0076] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A reflection confocal scanning microscope based on a flat objective lens, comprising: The first beam splitter (1) is suitable for splitting optical signals, wherein the optical signals include incident light signals and reflected light signals reflected by the sample being tested; The flat objective (2) is integrated into the reflective confocal scanning microscope as both a focusing lens and a collecting lens. It is suitable for forming a super-diffraction-limited focal spot on the incident light signal transmitted through the first beam splitter (1) and collecting the reflected light signal reflected by the test sample. The flat objective (2) is obtained by phase modulation using micro-nano structures. The micro-nano structures include either a Fresnel ring structure or a metasurface. The Fresnel ring structure is formed by etching ring grooves on a first dielectric substrate. An electric displacement stage (4) is suitable for carrying the test sample and controlling the movement of the test sample; The second beam splitter (5) is suitable for performing a second beam splitting process on the reflected light signal that has passed through the first beam splitter (1); The first lens (6) is suitable for focusing the reflected light signal transmitted through the second beam splitter (5); An aperture stop (7) is configured to be located at the focal plane of the first lens (6) and is suitable for filtering out defocused light from the reflected light signal passing through the first lens (6). The first photodetector (8) is adapted to detect the reflected light signal passing through the aperture stop (7); Among them, the reflective confocal scanning microscope based on a flat objective lens has a focal length greater than or equal to 0.5 mm, a focusing efficiency greater than 5%, and an imaging numerical aperture greater than 0.

7.

2. The microscope according to claim 1, wherein, The first beam splitter (1) and the second beam splitter (5) have the same structure, both being semi-transmissive and semi-reflective mirrors; The placement direction of the first beam splitter (1) is the same as that of the second beam splitter (5); The second beam splitter (5) is configured to be placed at an acute angle to the first lens (6) to ensure that only the reflected light signal after being reflected by the first beam splitter (1) passes through the second beam splitter (5).

3. The microscope according to claim 1, wherein, The diameter of the aperture stop (7) is between 10 nm and 5 mm.

4. The microscope according to claim 1, further comprising: The second lens (9) is used to focus the reflected light signal reflected by the second beam splitter (5); The second photodetector (10) is adapted to detect the reflected light signal passing through the second lens (9); The control device (11) is connected to the electric displacement stage (4), the first photodetector (8) and the second photodetector (10) at the same time, and is suitable for controlling the movement of the electric displacement stage (4) and the signal detection of the first photodetector (8) and the second photodetector (10).

5. The microscope according to claim 4, wherein, The electric displacement stage (4) includes one of an electric two-dimensional displacement stage and an electric three-dimensional displacement stage; The electric two-dimensional displacement stage and the electric three-dimensional displacement stage include: a piezoelectric displacement stage, a DC servo motor, a resonant motor, and a stepper motor. The first photodetector (8) includes: a photomultiplier tube; The second photodetector (10) includes either a CCD camera or a CMOS camera.

6. The microscope according to claim 1, wherein, The metasurface includes a second dielectric substrate and a dielectric nanostructure located on the second dielectric substrate, wherein the dielectric nanostructure includes a plurality of dielectric nanopillars; Wherein, the thickness of the first dielectric substrate is less than 2 mm; The thickness of the second dielectric substrate is less than 2 mm; The etching location, etching width, and etching depth of the groove are determined by the refractive index of the dielectric substrate material, the working wavelength, and the phase distribution of the flat objective lens.

7. The microscope according to claim 6, wherein, The first dielectric substrate and the second dielectric substrate are made of the same material, including one of the following: a quartz substrate, an alumina substrate, and a glass substrate; The materials of the dielectric nanopillars include one of TiO2, HfO2, ZrO2, GaN, Si2N3, Si, GaAs, ZnS, and AlN.

8. The microscope according to claim 6 or 7, wherein, The dielectric nanopillars include one of rectangular nanopillars, elliptical nanopillars, cross-shaped nanopillars, and L-shaped nanopillars; The height and width of the dielectric nanopillar are determined by the phase distribution of the flat objective lens, the dielectric nanopillar, and the operating wavelength.

Images