Pyramid mirror, super-resolution imaging system with pyramid mirror and morphology measurement system with pyramid mirror

Abstract

The invention relates to a pyramid mirror, a super-resolution imaging system with the pyramid mirror and a morphology measurement system with the pyramid mirror. The morphology measurement system comprises a pyramid mirror and a spatial light modulator, and the collimated laser beam is modulated by the spatial light modulator and then refracted or reflected by the pyramid mirror to reach an object to be measured; the super-resolution imaging system comprises a spatial light modulator, a pyramid mirror, a dichroscope, an objective lens, an imaging plane and a camera, the collimated laser beam is modulated by the spatial light modulator, refracted or reflected by the pyramid mirror, sequentially penetrates through the dichroscope and the objective lens and then reaches the imaging plane, and large-view-field structured light illumination is generated on the imaging plane. Light emitted by the imaging plane passes through the dichroscope and then reaches the camera, and super-resolution imaging is generated. Compared with the prior art, the device has the advantages that the spatial bandwidth product constraint of the spatial light modulator is broken through the pyramid mirror, so that the structured light illumination imaging visual field is not limited by the spatial light modulator any more, the imaging visual field is remarkably expanded, and the number of stripes is increased in cooperation with the pyramid mirror.

Description

Technical Field

[0001] The invention relates to fluorescence microscopy technology and three-dimensional surface topography measurement technology, in particular to a pyramid mirror and a super-resolution imaging system and a topography measurement system with the pyramid mirror. Background Art

[0002] Structured light illumination can be used to measure the surface of three-dimensional objects by projecting stripes of light with different phases and frequencies onto the surface of the object. Due to the shape and characteristics of the surface of the object, the projected light pattern will bend and deform. The camera captures the deformed image of the stripes projected onto the surface of the object, and obtains the three-dimensional shape information of the object by analyzing the deformation of the light.

[0003] Structured light illumination super-resolution microscopy is a microscopic imaging technology that breaks through the diffraction limit of traditional optical microscopes and achieves higher spatial resolution. Structured light illumination super-resolution microscopy uses illumination light with a specific structure to "transfer" high-frequency information outside the range of the optical transfer function to the low-frequency area during the imaging process; when the microscopic system captures the original low-frequency information of the sample and the high-frequency information after "transfer", it uses a specific algorithm to "restore" the high-frequency information to the original position, thereby expanding the frequency domain information of the sample passing through the microscopic system, so that the resolution of the reconstructed image exceeds the limit of the diffraction limit. Structured light illumination super-resolution microscopy has been widely used in the field of biomedical imaging due to its advantages of low photobleaching, high compatibility and fast imaging speed.

[0004] Common fast structured light illumination control is achieved through spatial light modulators, but due to the large pixels and small number of pixels of spatial light modulators, the field of view of structured light illumination stripes is limited. Therefore, large field of view structured light illumination super-resolution imaging can only be achieved through gratings, and its mechanical movement leads to slow imaging speed.

[0005] In summary, how to design a super-resolution imaging system with a large imaging field of view and fast imaging speed is a technical problem that needs to be solved. Summary of the invention

[0006] The purpose of the present invention is to provide a prism and a large-field-of-view super-resolution imaging system with a prism in order to overcome the defects of the prior art in that the field of view of structured light illumination stripes is limited and the imaging speed is slow.

[0007] The purpose of the present invention can be achieved by the following technical solutions:

[0008] According to a first aspect of the present invention, there is provided a prism mirror, comprising two bottom surfaces, at least one of which is provided with N working surfaces, wherein N≥2; the planes where the two working surfaces located on the same bottom surface are located are not parallel; each of the working surfaces passes at most one beam of light, and at least two beams of light pass through more than two different working surfaces respectively.

[0009] As a preferred technical solution, the prism further includes a first plane, which intersects with N working surfaces located on the same bottom surface.

[0010] As a preferred technical solution, the prism is fully transparent or has N working surfaces provided with anti-reflection films or reflective films.

[0011] As a preferred technical solution, the prism includes a frame and a plurality of parts connected to each other, wherein the frame is divided into a plurality of regions, and each part includes a working surface and is installed in a region of the frame.

[0012] According to a second aspect of the present invention, there is provided a topography measurement system having a prism as claimed in claim 1 or 2, comprising a prism and a spatial light modulator, wherein a collimated laser beam is modulated by the spatial light modulator and then reaches an object to be measured after being refracted or reflected by the prism.

[0013] According to a third aspect of the present invention, there is provided a super-resolution imaging system with the prism as claimed in claim 1 or 2, which is used for sample imaging and comprises a spatial light modulator, a prism, a dichroic mirror, an objective lens, an imaging plane and a camera, wherein a collimated laser beam is modulated by the spatial light modulator and refracted or reflected by the prism and then sequentially passes through the dichroic mirror and the objective lens to reach the imaging plane, thereby generating large-field-of-view structured light illumination on the imaging plane, and light emitted from the imaging plane passes through the dichroic mirror to reach the target surface of the camera, thereby generating super-resolution imaging.

[0014] As a preferred technical solution, the system also includes a lens group, a first reflector group and a spatial filter, wherein the lens group and the first reflector group are arranged in sequence between the spatial light modulator and the prism, and the spatial filter is located between the prism and the dichroic mirror; the lens group includes a first lens and a second lens, and the focal length of the first lens is greater than that of the second lens.

[0015] As a preferred technical solution, the system further comprises a polarization beam splitter prism, which is located between the spatial light modulator and the lens group. After the collimated laser beam passes through the polarization beam splitter prism, the polarization direction of the collimated laser beam is rotated by 90°.

[0016] As a preferred technical solution, a third lens is further provided between the prism and the spatial filter.

[0017] As a preferred technical solution, the system also includes a relay mirror group, which is located between the spatial filter and the dichroic mirror, and the light passing through the spatial filter reaches the dichroic mirror through the relay mirror group; the relay mirror group includes a second reflector group and / or a second lens group.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] 1) The N working surfaces of the prism mirror of the present invention increase the opening angle of the ±1st diffraction order for the structured light illumination stripes in multiple directions, thereby increasing the number of stripes; when the first plane exists, the passage of the 0th diffraction order can be guaranteed, and two-dimensional structured light illumination and three-dimensional structured light illumination imaging can be realized simultaneously; the morphology measurement system significantly expands the imaging field of view, and the number of stripes is increased by cooperating with the prism mirror. The system only needs a low-resolution spatial light modulator to generate high-resolution and large-field structured light illumination stripes, thereby reducing the device cost; the introduction of the prism mirror in the super-resolution imaging system breaks the spatial bandwidth product constraint of the spatial light modulator, so that the structured light illumination imaging field of view is no longer limited by the spatial light modulator; the provision of a reflective film on the prism mirror can achieve the same effect as that without the provision of a reflective film, and is suitable for situations where space is limited and there are requirements;

[0020] 2) A third lens is placed after the prism mirror of the present invention to ensure that the focus of each diffraction order light beam is at the focus of the lens, and a spatial filter is placed at another focal plane of the lens to allow the 0th or ±1st order diffraction order to pass through and modulate it into s-polarized light. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic diagram of the overall structure of a prism mirror according to Embodiment 1 of the present invention;

[0022] Figure 2 Another schematic diagram of the overall structure of the prism lens according to Embodiment 1 of the present invention;

[0023] Figure 3 This is a schematic diagram of the overall structure of a prism mirror according to Embodiment 2 of the present invention;

[0024] Figure 4 Schematic diagram of another overall structure of the prism mirror according to embodiment 2 of the present invention;

[0025] Figure 5 This is a schematic diagram of the overall structure of a pyramid mirror according to Embodiment 3 of the present invention;

[0026] Figure 6 A schematic diagram of the structure of a pyramid mirror coated with a reflective film according to the present invention, wherein the height of the first vertex is higher than the height of any point on the working surface;

[0027] Figure 7 A schematic diagram of the structure of a pyramid mirror coated with a reflective film according to the present invention, wherein the height of the first vertex is lower than the height of any point on the working surface;

[0028] Figure 8 This is a first schematic diagram of the prism mirror of the present invention when it is working;

[0029] Fig. 9 A second schematic diagram of the prism mirror of the present invention when it is working;

[0030] Fig.10 This is a schematic diagram of the overall structure of the pyramid mirror in Example 5 of the present invention;

[0031] Fig.11 It is a schematic diagram of the structure of the topography measurement system of the present invention;

[0032] Fig.12 A first schematic diagram of a prism mirror coated with a reflective film used in a profile measurement system of the present invention;

[0033] Fig.13 A second schematic diagram of a shape measurement system of the present invention using a pyramid mirror coated with a reflective film;

[0034] Fig.14 A first schematic diagram of a shape measurement system of the present invention using a reflective film-coated pyramid mirror and a polarization beam splitter prism;

[0035] Fig.15 A second schematic diagram of the shape measurement system of the present invention using a reflective film-coated pyramid mirror and a polarization beam splitter prism;

[0036] Fig.16 It is a first structural schematic diagram of the super-resolution imaging system of the present invention;

[0037] Fig.17 It is a second structural schematic diagram of the super-resolution imaging system of the present invention;

[0038] Fig.18 The wide-field and super-resolution images of the 100nm fluorescent bead specimen obtained by the super-resolution imaging system of the present invention;

[0039] Fig.19 for Fig.18 A partial schematic diagram of the center location;

[0040] The numbers in the figure show:

[0041] 1. spatial light modulator, 2. polarization beam splitter, 3. first lens, 4. second lens, 51. first reflector group, 52. second reflector group, 53. third reflector group, 6. pyramid mirror, 61. bottom surface, 62. working surface, 7. spatial filter, 8. fourth lens, 9. fifth lens, 10. dichroic mirror, 11. objective lens, 12. tube lens, 13. camera, 14. third lens. DETAILED DESCRIPTION

[0042] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0043] Example 1

[0044] The present embodiment provides a prism, which is a cube as a whole and includes two bottom surfaces 61, wherein at least one bottom surface 61 is provided with N working surfaces 62, wherein N≥2; when N=2, the planes where the two working surfaces 62 located on the same bottom surface 61 are located are not parallel and intersect at the first side, and the height of the first side is higher or lower than the height of any point on the working surface 62; when N>2, the planes where all the working surfaces 62 located on the same bottom surface 61 are located are not parallel and intersect at the first vertex, and the height of the first vertex is higher or lower than the height of any point on the working surface 62; at least two light beams pass through the two working surfaces 62 located on the same bottom surface 61 respectively. The prism 6 can be fully transparent as a whole, or an anti-reflection film or a reflective film can be provided on the working surface 62. The prism 6 provided with a reflective film is as follows: Figure 6 and Figure 7 shown.

[0045] like Figure 1 As shown, the prism mirror 6 can be a cylinder as a whole, N=6, that is, six working surfaces 62 are provided on one bottom surface 61, and the six working surfaces 62 are designed for structured light illumination stripes in three directions to increase the opening angles of ±1st diffraction orders in three directions.

[0046] like Figure 2 As shown, the prism mirror 6 as a whole can be a hexagonal prism, and six working surfaces 62 are provided on one bottom surface 61 .

[0047] The angle between the six working surfaces 62 and the bottom surface 61 needs to be calculated and designed according to the actual application and the optical path. In this embodiment, the angle is about 18°. For different applications, different numbers of faces of the prism mirror 6 can also be designed. For example, a decaprism mirror can be used for second-order nonlinear structured light illumination. Linear structured light illumination can also be achieved by using six faces of a twelve-prism mirror. A prism reflector (i.e., a reflective film is coated on the N working surfaces 62 of the prism mirror 6) can also achieve the same effect.

[0048] like Figure 8 and Fig. 9 As shown, the two bottom surfaces 61 of the prism mirror 6 are both provided with working surfaces 62 , and when the first vertex is higher or lower than the working surface 62 , the refraction effect on the incident light beam is different.

[0049] Example 2

[0050] Compared with the pyramid mirror 6 in embodiment 1, this embodiment further includes a first plane, which intersects with N working planes 62 located on the same bottom surface 61. The first plane ensures the passage of the 0th order diffraction order and is compatible with two-dimensional structured light illumination imaging and three-dimensional structured light illumination imaging.

[0051] like Figure 3 As shown, the first plane is parallel to a bottom surface 61 of the prism mirror 6 which is a cylindrical body.

[0052] like Figure 4 As shown, the first plane is parallel to a bottom surface 61 of the pyramid mirror 6 which is a quadrangular prism as a whole.

[0053] Example 3

[0054] This embodiment provides a prism, including N parts spliced ​​together, each part including a working surface 62, which are spliced ​​together to form the prism 6 in Embodiment 1 or Embodiment 2.

[0055] Example 4

[0056] like Figure 5 As shown, this embodiment provides a prism, including a frame, wherein the interior of the frame is divided into N or N+1 regions, and a lens is installed in each region. When the interior of the frame is divided into N regions, the prism 6 with the same overall shape as that of the first embodiment is formed; when the interior of the frame is divided into N+1 regions, the prism 6 with the same overall shape as that of the second embodiment is formed.

[0057] Example 5

[0058] like Fig.10 As shown, this embodiment provides a prism mirror, including two bottom surfaces 61, one of the bottom surfaces 61 is provided with four working surfaces 62 intersecting in sequence.

[0059] Example 6

[0060] This embodiment provides a shape measurement system with the prism mirror 6 in embodiments 1 to 5, including the prism mirror 6 and a spatial light modulator 1. The spatial light modulator 1 modulates the collimated laser beam, and the collimated laser beam reaches the object to be measured after being refracted or reflected by the prism mirror 6.

[0061] like Fig.11 As shown, the prism mirror 6 is fully transparent or the working surface 62 is provided with an anti-reflection film, and the dotted line is the position where the object is located. Figure 12 to Figure 15 As shown, a reflective film is provided on the working surface 62 of the prism mirror 6, and when the first vertex is higher or lower than the working surface 62, the refraction effect on the incident light beam is different.

[0062] This embodiment uses a pyramid mirror 6, which significantly increases the number of fringes and expands the imaging field of view, thereby reducing the device cost, while only requiring a low-resolution spatial light modulator 1.

[0063] Example 7

[0064] This embodiment provides a super-resolution imaging system with the prism mirror 6 in Embodiments 1 to 5, which is used for sample imaging, and includes a spatial light modulator 1, a prism mirror 6, a dichroic mirror 10, an objective lens 11, an imaging plane and a camera 13.

[0065] The collimated laser beam is modulated by the spatial light modulator 1 and refracted or reflected by the prism mirror 6, and then passes through the dichroic mirror 10 and the objective lens 11 in sequence to reach the imaging plane, generating large-field structured light illumination on the imaging plane. The light emitted from the imaging plane passes through the dichroic mirror 10 and reaches the target surface of the camera 13, generating super-resolution imaging.

[0066] A lens group and a first reflector group 51 may be arranged between the spatial light modulator 1 and the prism 6. The lens group includes a first lens 3 and a second lens 4. The focal length of the first lens 3 is greater than that of the second lens 4. The use of the first lens 3 and the second lens 4 with different focal lengths can separate the diffraction orders emitted by the spatial light modulator 1 as quickly as possible; the light beam passing through the laser beam splitting assembly passes through the first lens 3 and the second lens 4 in sequence. The first lens 3 may have a focal length of 150 mm; the second lens 4 may have a focal length of 50 mm. The surface of the first reflector group 51 is coated with a silver film.

[0067] A polarization beam splitter prism 2 may be arranged between the spatial light modulator 1 and the lens group. The collimated laser beam passes through the polarization beam splitter prism 2 to reach the spatial light modulator 1, and the polarization direction of the beam is rotated 90° after passing through the spatial light modulator 1 and then passes through the polarization beam splitter prism 2 again. The optional polarization beam splitter prism 2 is: extinction ratio (Tb:Ts)>1000:1, L=25.4mm, lbtek; the spatial light modulator 1 is: 3DM QXGA LCoS, Kopin.

[0068] A spatial filter 7 may be arranged between the pyramid mirror 6 and the dichroic mirror 10 .

[0069] A third lens 14 may be arranged between the prism mirror 6 and the spatial filter 7 , and the third lens 14 may have a focal length of 50 mm.

[0070] A relay mirror group may be arranged between the spatial filter 7 and the dichroic mirror 10, the relay mirror group including a second reflector group 52, a third reflector group 53, a fourth lens 8 and a fifth lens 9, and the light beam passing through the spatial filter 7 sequentially passes through the second reflector group 52, the fourth lens 8, the third reflector group 53 and the fifth lens 9. The fourth lens 8 may have a focal length of 400 mm; the fifth lens 9 may have a focal length of 200 mm; the second reflector group 52 and the third reflector group 53 are coated with a silver film.

[0071] The diameter of each lens and reflector needs to not cut the light, and the focal length needs to match the fringe thickness and field of view size.

[0072] like Fig.17As shown, the collimated laser beam is reflected by the polarization beam splitter prism 2 (PBS) to the spatial light modulator 1 (SLM), and the SLM loading stripes rotate the polarization direction of the beam by 90° so that it passes through the polarization beam splitter prism 2. The first lens 3 and the second lens 4 of the lens group increase the opening angle of the light beams of different diffraction orders, thereby separating the ±1st order diffraction order light beams as quickly as possible. After the light beam passes through the first reflector group 51, the separated ±1st order diffraction beams are refracted by the prism 6, the opening angle becomes larger, and are focused by the third lens 14 to the spatial filter 7 (Fourier surface), and other unnecessary orders are removed by the spatial filter 7. The focused ±1st order diffraction orders are relayed to the rear focal plane of the objective lens 11 by the fourth lens 8 and the fifth lens 9 through the reflector and the dichroic mirror 10. The excited fluorescent object is collected by the objective lens 11 and imaged onto the camera 13 through the dichroic mirror 10 and the tube lens 12.

[0073] The present invention uses the existing structured light illumination super-resolution imaging process to perform imaging. Usually, two-dimensional linear structured light illumination super-resolution imaging uses three stripe directions, three phases in each direction, and automatically captures the image and reconstructs it using a frequency domain assembly algorithm. The imaging resolution can reach 100nm.

[0074] like Fig.18 and Fig.19 As shown in the figure, the field of view of fluorescent bead imaging is about 200μm. By comparing the wide-field and super-resolution results at the center and corner positions, the spatial resolution of the wide-field and super-resolution images is obtained by performing correlation analysis and calculation on the fluorescent bead imaging image in a 64x64 area. The spatial resolution of the entire image under super-resolution reaches 138.1 nanometers.

[0075] The present invention increases the opening angle of the ±1st diffraction order in structured light illumination by using the prism mirror 6, thereby increasing the number of fringes and breaking the spatial bandwidth product constraint of the spatial light modulator 1, so that the imaging field of structured light illumination is no longer limited by the spatial light modulator 1; only a low-resolution spatial light modulator 1 is needed to generate structured light illumination fringes with high resolution and large field of view, thereby reducing the cost of the device; the above effect can be achieved by simply adding the prism mirror 6, with a simple structure and low cost.

[0076] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed by the present invention, and these modifications or replacements should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A prism lens, characterized in that: The invention comprises at least one bottom surface (61), wherein N working surfaces (62) are arranged on the bottom surface (61), wherein N≥2; the planes where two working surfaces (62) located on the same bottom surface (61) are located are not parallel; and at least two beams of light respectively pass through more than two different working surfaces.

2. A prism lens according to claim 1, characterized in that: The prism mirror (6) also includes a first plane, which intersects with N working surfaces (62) located on the same bottom surface (61).

3. The prism mirror according to claim 1, characterized in that: The prism mirror (6) is fully transparent or has N working surfaces (62) provided with anti-reflection films or reflection films.

4. The prism mirror according to claim 1, characterized in that: The pyramid mirror (6) comprises a frame and a plurality of parts connected to each other. The frame is divided into a plurality of areas. Each part comprises a working surface (62) and is installed in an area of ​​the frame.

5. A shape measurement system with a pyramid mirror according to any one of claims 1 to 4, characterized in that: It comprises a prism mirror (6) and a spatial light modulator (1). The collimated laser beam is modulated by the spatial light modulator (1) and then reaches the object to be measured after being refracted or reflected by the prism mirror (6).

6. A super-resolution imaging system with a pyramid mirror according to any one of claims 1 to 4, used for sample imaging, characterized in that: The invention comprises a spatial light modulator (1), a prism (6), a dichroic mirror (10), an objective lens (11), an imaging plane and a camera (13). The collimated laser beam is modulated by the spatial light modulator (1) and refracted or reflected by the prism (6), then sequentially passes through the dichroic mirror (10) and the objective lens (11) to reach the imaging plane, thereby generating large-field structured light illumination on the imaging plane. The light emitted by the imaging plane passes through the dichroic mirror (10) and reaches the target surface of the camera (13), thereby generating super-resolution imaging.

7. The super-resolution imaging system according to claim 6, characterized in that: The system further comprises a lens group, a first reflector group (51) and a spatial filter (7), wherein the lens group and the first reflector group (51) are sequentially arranged between the spatial light modulator (1) and the prism (6), and the spatial filter (7) is located between the prism (6) and the dichroic mirror (10); the lens group comprises a first lens (3) and a second lens (4), and the focal length of the first lens (3) is greater than that of the second lens (4).

8. The super-resolution imaging system according to claim 7, characterized in that: The system also comprises a polarization beam splitter prism (2), which is located between the spatial light modulator (1) and the lens group (3). After the collimated laser beam passes through the polarization beam splitter prism (2), the polarization direction of the collimated laser beam is rotated by 90 degrees.

9. The super-resolution imaging system according to claim 6, characterized in that: A third lens (14) is also provided between the prism mirror (6) and the spatial filter (7).

10. The super-resolution imaging system according to claim 6, characterized in that: The system also includes a relay mirror group, which is located between the spatial filter (7) and the dichroic mirror (10), and the light passing through the spatial filter (7) reaches the dichroic mirror (10) through the relay mirror group; the relay mirror group includes a second reflector group (52) and / or a second lens group.

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