Microobjective and microscopic imaging system
By using lens combinations made of fused silica and calcium fluoride materials, an imaging module and a correction module were designed, solving the problem of balancing ultraviolet and visible light imaging, and realizing multi-band imaging and low-cost, high-quality imaging with a single microscope objective.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- TAIYUAN FENGHUA INFORMATION EQUIP
- Filing Date
- 2026-03-16
- Publication Date
- 2026-05-15
AI Technical Summary
Existing technologies cannot simultaneously meet the imaging requirements of ultraviolet and visible light bands, resulting in the need to set up two sets of detection structures, which increases the system complexity and cost.
A lens assembly made of fused silica and calcium fluoride was used to design an imaging module and a correction module to achieve imaging capability in the ultraviolet to visible light band. Chromatic aberration correction was optimized through lens assembly and parameter settings.
It enables imaging in the ultraviolet to visible light bands simultaneously in a single microscope objective, reducing system complexity and cost while improving imaging quality.
Smart Images
Figure CN122043715A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of microscopic imaging technology, and more specifically, to a microscope objective and a microscopic imaging system. Background Technology
[0002] In a microscopic imaging system, imaging is usually achieved by using a microscope objective lens and a tube lens. As an important optical element in microscopic imaging, the objective lens has different specific parameter settings for different application scenarios.
[0003] In the field of semiconductor inspection, in most cases, multiple monochromatic lights of different wavelengths are required to image into different channels. The ultraviolet band refers to a 10nm narrowband wave with wavelengths centered at 310nm and 355nm. For example, in semiconductor inspection processes, light near 300nm has good excitation properties and is very suitable for inspection. The visible light band refers to a 20nm narrowband wave with wavelengths centered at 450nm, 520nm, and 620nm, including RGB.
[0004] In the context of monochromatic light imaging applications, especially for objectives that simultaneously image ultraviolet and visible light, conventional glass materials are difficult to apply due to the wide wavelength range encompassing both ultraviolet and visible light bands. However, setting separate objectives for ultraviolet and visible light imaging would necessitate two highly similar detection structures to achieve the desired functionality, significantly increasing structural complexity and detection costs. Summary of the Invention
[0005] This application provides a microscope objective and a microscope imaging system. The microscope objective can meet the imaging requirements covering the ultraviolet and visible light bands, and has a compact structure, reducing the complexity of the system.
[0006] To achieve the above objectives, the technical solutions adopted in the embodiments of this application are as follows: One aspect of this application provides a microscope objective, including an imaging module and a correction module arranged sequentially from the object side to the image side. The imaging module includes a first negative lens, a second positive lens, a third negative lens, a fourth positive lens, a fifth negative lens, a sixth positive lens, a seventh negative lens, an eighth positive lens, a ninth negative lens, and a tenth positive lens arranged sequentially. The correction module includes an eleventh positive lens and a twelfth negative lens arranged sequentially. The optical elements in both the imaging module and the correction module are made of fused silica or calcium fluoride material, respectively. The total focal length of the imaging module is f=40mm, and the correction module is used to adjust aberrations to achieve clear imaging at infinity on the image side.
[0007] In one feasible embodiment of this application, the positive lens in the imaging module is made of calcium fluoride material, and the negative lens in the imaging module is made of fused silica material.
[0008] In a feasible implementation manner of the embodiment of the present application, the focal length f1 of the first negative lens < 0, 0 < |f1 / f| < 1; the focal length f2 of the second positive lens > 0, 0.5 < |f2 / f| < 2; the focal length f3 of the third negative lens < 0, 2 < |f3 / f| < 5; the focal length f4 of the fourth positive lens > 0, 0 < |f4 / f| < 1; the focal length f5 of the fifth negative lens < 0, 0 < |f5 / f| < 1; the focal length f6 of the sixth positive lens > 0, 0 < |f6 / f| < 1; the focal length f7 of the seventh negative lens < 0, 1 < |f7 / f| < 5; the focal length f8 of the eighth positive lens > 0, 1 < |f8 / f| < 2.5; the focal length f9 of the ninth negative lens < 0, 1 < |f9 / f| < 4.5; the focal length f 10 > 0, 1 < |f 10 / f| < 3.5.
[0009] In a feasible implementation manner of the embodiment of the present application, the focal length f 11 > 0, 2 < |f 11 / f| < 5; the focal length f of the twelfth negative lens 12 < 0, 1 < |f 12 / f| < 3.
[0010] In a feasible implementation manner of the embodiment of the present application, the eleventh positive lens and the twelfth negative lens are made of calcium fluoride material.
[0011] In a feasible implementation manner of the embodiment of the present application, the total working distance WD of the imaging module and the correction module > 15 mm, and the numerical aperture NA > 0.26.
[0012] In a feasible implementation manner of the embodiment of the present application, there is no cemented surface between the lenses of the imaging module, between the lenses of the correction module, and between the adjacent lenses of the imaging module and the correction module.
[0013] In a feasible implementation manner of the embodiment of the present application, the distance between the tenth positive lens of the imaging module and the eleventh positive lens of the correction module is between 1 mm and 30 mm.
[0014] On the other hand, the embodiment of the present application provides a microscopic imaging system, including the microscopic objective lens of any one of the foregoing, and a tube lens and a camera arranged on the object side of the microscopic objective lens.
[0015] In a feasible implementation manner of the embodiment of the present application, the magnification β of the microscopic objective lens = 5×, the object field = φ4 mm, the focal length of the tube lens is 200 mm, and the parallel light beam emitted by the microscopic objective lens is converged by the tube lens and clearly imaged in the camera.
[0016] The microscope objective provided in this application includes an imaging module and a correction module arranged sequentially from the object side to the image side. The imaging module includes a first negative lens, a second positive lens, a third negative lens, a fourth positive lens, a fifth negative lens, a sixth positive lens, a seventh negative lens, an eighth positive lens, a ninth negative lens, and a tenth positive lens arranged sequentially. The correction module includes an eleventh positive lens and a twelfth negative lens arranged sequentially. In this embodiment, the optical elements in the imaging module and the correction module are made of fused silica or calcium fluoride, respectively. Fused silica is an amorphous glass made by rapidly cooling high-purity silicon dioxide after melting. It has good transmittance from deep ultraviolet to near-infrared light range and can achieve imaging capability covering the ultraviolet to visible light band. Calcium fluoride is an optical crystal grown from natural fluorite single crystals. It also meets the transmittance requirements from deep ultraviolet to mid-infrared bands and has natural apochromatic ability. In this embodiment, the multiple optical lenses in the microscope objective are made of fused silica and calcium fluoride and used in combination. While meeting the imaging capability in the ultraviolet to visible light bands, they coordinate to correct chromatic aberration, which helps to restore the true image and present the image clearly. The microscope objective of this application first sets up the output imaging beam in the imaging module with a combination of negative and positive lenses and specific lens parameters. The total focal length of the imaging module is f=40mm. Then, the aberration is adjusted by the correction module. The parallel beam emitted by the imaging module is clearly imaged at infinity on the image side after the aberration is adjusted by the correction module. Attached Figure Description
[0017] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.
[0018] Figure 1 A schematic diagram of the optical path of a microscope objective provided in this application embodiment; Figure 2 A dot matrix pattern in the ultraviolet light band provided in this application embodiment; Figure 3 This application provides another dot pattern in the ultraviolet light band. Figure 4 A dot matrix pattern in the visible light band is provided as an embodiment of this application; Figure 5 Another dot pattern in the visible light band provided in this application embodiment; Figure 6 This application provides yet another dot pattern in the visible light band; Figure 7A field curvature and distortion map in the ultraviolet band provided in this application embodiment; Figure 8 Another field curvature and distortion diagram in the ultraviolet band provided in this application embodiment; Figure 9 A field curvature and distortion map in the visible light band is provided as an embodiment of this application; Figure 10 Another field curvature and distortion diagram in the visible light band provided in this application embodiment; Figure 11 This application provides yet another field curvature and distortion diagram in the visible light band.
[0019] Icons: AA - Imaging module; BB - Correction module; 01 - First negative lens; 02 - Second positive lens; 03 - Third negative lens; 04 - Fourth positive lens; 05 - Fifth negative lens; 06 - Sixth positive lens; 07 - Seventh negative lens; 08 - Eighth positive lens; 09 - Ninth negative lens; 10 - Tenth positive lens; 11 - Eleventh positive lens; 12 - Twelfth negative lens. Detailed Implementation
[0020] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. It should be noted that, in the absence of conflict, the various features in the embodiments of this application can be combined with each other, and the combined embodiments are still within the protection scope of this application.
[0021] In the description of this application, it should be noted that the terms "upper," "lower," "left," "right," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and therefore should not be construed as limiting this application. In addition, the terms "first," "second," and "third," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.
[0022] In the field of semiconductor inspection, such as the detection of various defects on wafer surfaces, multiple monochromatic light imaging wavelengths are required for different defect types. For example, light around 300nm has good excitation properties and is suitable for detecting various defects. Therefore, the detection light needs to cover a wide wavelength range from ultraviolet to visible light. However, objectives that typically meet ultraviolet and visible light requirements cannot be used across different wavelengths to achieve cross-band compatibility. If separate objectives are set for different monochromatic light bands, multiple similar detection structures are required, significantly increasing the complexity and cost of the inspection system.
[0023] Based on this, embodiments of this application provide a microscope objective, such as... Figure 1 As shown, the microscope objective includes an imaging module AA and a correction module BB arranged sequentially from the object side to the image side. The imaging module AA includes a first negative lens 01, a second positive lens 02, a third negative lens 03, a fourth positive lens 04, a fifth negative lens 05, a sixth positive lens 06, a seventh negative lens 07, an eighth positive lens 08, a ninth negative lens 09, and a tenth positive lens 10 arranged sequentially. The correction module BB includes an eleventh positive lens 11 and a twelfth negative lens 12 arranged sequentially. The optical elements in the imaging module AA and the correction module BB are made of fused silica or calcium fluoride material, respectively. The total focal length of the imaging module AA is f=40mm, and the correction module BB is used to adjust aberrations to achieve clear imaging at infinity on the image side.
[0024] The microscope objective is configured with an imaging module AA and a correction module BB sequentially from the object side to the image side. The imaging module AA includes a first negative lens 01, a second positive lens 02, a third negative lens 03, a fourth positive lens 04, a fifth negative lens 05, a sixth positive lens 06, a seventh negative lens 07, an eighth positive lens 08, a ninth negative lens 09, and a tenth positive lens 10 arranged sequentially. The light beam is incident on the imaging module AA from the object side. The first negative lens 01 and the second positive lens 02 form a lens group. Similarly, the third negative lens 03 and the fourth positive lens 04, the fifth negative lens 05 and the sixth positive lens 06, the seventh negative lens 07 and the eighth positive lens 08, and the ninth negative lens 09 and the tenth positive lens 10 also form lens groups. The total focal length of the imaging module AA is f=40mm, so that the incident light beam is magnified step by step in the field of view and finally exits as a parallel beam for imaging after passing through the tenth positive lens 10. The first negative lens 01 to the tenth positive lens 10 in the imaging module AA are made of fused silica or calcium fluoride material to ensure imaging capability from the ultraviolet band to the visible band. Furthermore, since the imaging module AA includes lenses made of calcium fluoride material, it is also possible to achieve apochromatic processing of the imaging beam.
[0025] A parallel beam emitted from the image side of the imaging module AA is incident on the correction module BB. The correction module BB includes an eleventh positive lens 11 and a twelfth negative lens 12 arranged sequentially. The parallel beam is emitted in parallel after the aberration is adjusted by the eleventh positive lens 11 and the twelfth negative lens 12 in sequence, so that a clear image can be formed at infinity at the image side. The eleventh positive lens 11 and the twelfth negative lens 12 of the correction module BB can also be made of fused silica or calcium fluoride material, respectively, to meet the aberration adjustment and correction of parallel beams from the ultraviolet band to the visible light band.
[0026] The microscopic objective lens provided by the embodiment of the present application includes an imaging module AA and a correction module BB arranged in sequence from the object side to the image side. The imaging module AA includes a first negative lens 01, a second positive lens 02, a third negative lens 03, a fourth positive lens 04, a fifth negative lens 05, a sixth positive lens 06, a seventh negative lens 07, an eighth positive lens 08, a ninth negative lens 09, and a tenth positive lens 10 arranged in sequence; the correction module BB includes an eleventh positive lens 11 and a twelfth negative lens 12 arranged in sequence. Among them, the optical elements in the imaging module AA and the correction module BB are respectively prepared from fused silica or calcium fluoride materials. Fused silica is an amorphous glass made by melting high-purity silica and then rapidly cooling it, which has good transmittance in the range from deep ultraviolet to near-infrared light and can achieve imaging capabilities covering the ultraviolet to visible light bands. Calcium fluoride is an optical crystal cultivated from natural fluorite single crystals, which also meets the light transmission capabilities in the deep ultraviolet to mid-infrared bands and naturally has the ability of apochromatism. In the microscopic objective lens of the embodiment of the present application, multiple optical lenses are respectively prepared from fused silica and calcium fluoride materials and used in combination, which can meet the imaging capabilities in the ultraviolet to visible light bands while coordinating the correction of chromatic aberration, helping to truly restore and clearly present the imaging image. In the microscopic objective lens of the embodiment of the present application, first, an imaging beam is set out in the imaging module AA with a combination of paired negative lenses and positive lenses and specific lens parameters. The total focal length f of the imaging module AA is 40 mm, and then the aberration is adjusted by the correction module BB. The parallel beam emitted by the imaging module AA is clearly imaged at infinity on the image side after the aberration is adjusted by the correction module BB.
[0027] In a feasible implementation manner of the embodiment of the present application, the positive lenses in the imaging module AA are prepared from calcium fluoride materials, and the negative lenses in the imaging module AA are prepared from fused silica materials.
[0028] The positive lenses in the imaging module AA, including the second positive lens 02, the fourth positive lens 04, the sixth positive lens 06, the eighth positive lens 08, and the tenth positive lens 10, are prepared from calcium fluoride materials. The negative lenses in the imaging module AA, including the first negative lens 01, the third negative lens 03, the fifth negative lens 05, the seventh negative lens 07, and the ninth negative lens 09, are prepared from fused silica materials. That is, in the imaging module AA, the negative lenses prepared from fused silica materials and the positive lenses prepared from calcium fluoride materials are arranged alternately in pairs. Through the alternately arranged lenses of fused silica materials and calcium fluoride materials, the imaging module AA optimizes the combination setting of lens materials during the imaging process, truly restores and presents clear images in the ultraviolet to visible light band range while optimizing chromatic aberration.
[0029] In a feasible implementation manner of the embodiment of the present application, The focal length f1 of the first negative lens 01 < 0, 0 < |f1 / f| < 1; The focal length f2 of the second positive lens 02 > 0, 0.5 < |f2 / f| < 2; The focal length f3 of the third negative lens 03 < 0, 2 < |f3 / f| < 5; The focal length f4 of the fourth positive lens 04 > 0, 0 < |f4 / f| < 1; The focal length f5 of the fifth negative lens 05 < 0, 0 < |f5 / f| < 1; The focal length f6 of the sixth positive lens 06 > 0, 0 < |f6 / f| < 1; The focal length f7 of the seventh negative lens 07 < 0, 1 < |f7 / f| < 5; The focal length f8 of the eighth positive lens 08 > 0, 1 < |f8 / f| < 2.5; The focal length f9 of the ninth negative lens 09 < 0, 1 < |f9 / f| < 4.5; The focal length f of the tenth positive lens 10 10 > 0, 1 < |f 10 / f| < 3.5.
[0030] Exemplarily, as Figure 1 shown, the focal length f1 of the first negative lens 01 < 0, the first negative lens 01 is a meniscus lens convex toward the image side, the incident light side is concave and the outgoing light side is convex, 0 < |f1 / f| < 1; the focal length f2 of the second positive lens 02 > 0, the second positive lens 02 is a meniscus lens convex toward the image side, the incident light side is concave and the outgoing light side is convex, 0.5 < |f2 / f| < 2; the focal length f3 of the third negative lens 03 < 0, the third negative lens 03 is a meniscus lens convex toward the object side, the incident light side is convex and the outgoing light side is concave, 2 < |f3 / f| < 5; the focal length f4 of the fourth positive lens 04 > 0, the fourth positive lens 04 is a biconvex spherical mirror, 0 < |f4 / f| < 1; the focal length f5 of the fifth negative lens 05 < 0, the fifth negative lens 05 is a biconcave spherical mirror, 0 < |f5 / f| < 1; the focal length f6 of the sixth positive lens 06 > 0, the sixth positive lens 06 is a biconvex spherical mirror, 0 < |f6 / f| < 1; the focal length f7 of the seventh negative lens 07 < 0, the seventh negative lens 07 is a meniscus lens convex toward the object side, the incident light side is convex and the outgoing light side is concave, 1 < |f7 / f| < 5; the focal length f8 of the eighth positive lens 08 > 0, the eighth positive lens 08 is a biconvex spherical mirror, 1 < |f8 / f| < 2.5; the focal length f9 of the ninth negative lens 09 < 0, the ninth negative lens 09 is a plano - concave mirror, the incident light side is concave and the outgoing light side is flat, 1 < |f9 / f| < 4.5; the focal length f of the tenth positive lens 10 10 > 0, the tenth positive lens 10 is a plano - convex mirror, the incident light side is convex and the outgoing light side is flat, 1 < |f 10 / f| < 3.5.
[0031] In a feasible implementation manner of the embodiment of the present application, the focal length f of the eleventh positive lens 1111 >0, 2< |f >0, 2< |f 11 / f| < 5; The focal length f of the twelfth negative lens 12 12 <0, 1< |f 12 / f| < 3.
[0032] As Figure 1 shown, the eleventh positive lens 11 is a double convex spherical mirror, and the focal length f of the eleventh positive lens 11 11 >0, 2< |f 11 / f| < 5, the twelfth negative lens 12 is a meniscus lens convex towards the image side, with the incident light side being concave and the outgoing light side being convex, and the focal length f of the twelfth negative lens 12 12 <0, 1< |f 12 / f| < 3. The combined optical power of the eleventh positive lens 11 and the twelfth negative lens 12 is almost zero, that is, the combination of the eleventh positive lens 11 and the twelfth negative lens 12 does not adjust the optical path of the imaging beam. The imaging beam is incident as a parallel beam and still exits as a parallel beam, and only corrects the aberration of the imaging beam through the mutual cooperation of the eleventh positive lens 11 and the twelfth negative lens 12.
[0033] In a feasible implementation manner of the embodiment of the present application, the eleventh positive lens 11 and the twelfth negative lens 12 are prepared from calcium fluoride material.
[0034] The correction module BB composed of the eleventh positive lens 11 and the twelfth negative lens 12 prepared from calcium fluoride material has an extremely high Abbe number, exhibits extremely low dispersion, and the refractive index changes very little with wavelength, having core optical advantages and achieving better apochromatic ability. Especially in the visible light and ultraviolet light wavelength ranges, it can maintain the polarization state and working accuracy of the system.
[0035] In a feasible implementation manner of the embodiment of the present application, the total working distance WD of the imaging module AA and the correction module BB > 15 mm, and the numerical aperture NA > 0.26.
[0036] In a feasible implementation manner of the embodiment of the present application, there is no cemented surface between the lenses of the imaging module AA, between the lenses of the correction module BB, and between the adjacent lenses of the imaging module AA and the correction module BB.
[0037] As Figure 1As shown, between the first negative lens 01 and the twelfth negative lens 12, including the imaging module AA and the correction module BB, any two adjacent lenses maintain a close distance but are not cemented together; that is, there is no cemented surface between any adjacent lenses. In the microscope objectives of this embodiment, the absence of cemented surfaces between any adjacent lenses improves the laser damage threshold when the microscope objectives are used in environments with high-power light sources and high ambient temperatures, preventing cemented surfaces from detaching. The gaps between adjacent lenses also facilitate heat dissipation, making it more suitable for use in semiconductor testing equipment.
[0038] In one feasible implementation of the embodiments of this application, such as Figure 1 As shown, the distance between the tenth positive lens 10 of the imaging module AA and the eleventh positive lens 11 of the correction module BB is 1mm-30mm.
[0039] The tenth positive lens 10 of the imaging module AA and the eleventh positive lens 11 of the correction module BB can maintain a relatively close working distance, just like other lenses, in order to avoid the microscope objective of this application being too large in size.
[0040] However, in some application scenarios, such as in multi-channel microscopic imaging detection systems, it is necessary to introduce illumination into the imaging channel. A gap space can be reserved between the imaging module AA and the correction module BB so that optical path deflection elements such as mirrors, dichroic mirrors, or beam splitters can be set in this space in the optical path. In the case that the space between the microscope objective and its image-side tube lens in the embodiments of this application is insufficient, the illumination light channel or autofocus can be separated by the optical path deflection elements between the imaging module AA and the correction module BB.
[0041] For example, the various optical lenses of the imaging module AA and the correction module BB in the microscope objective of this application embodiment can be specifically set according to the parameters in Table 1 below.
[0042] Table 1
[0043] In this specific embodiment of the present application, the air gap of the object surface is the air distance between the location of the light source and the first negative lens 01 of the imaging module AA. The mechanical contact surface refers to the mechanical structural surface that the light-emitting surface of the twelfth negative lens 12 is attached to when the microscope objective of the present application is used in a semiconductor inspection device.
[0044] It should be noted that, in this embodiment of the application, the front surface of the tenth positive lens 10 of the imaging module AA can serve as the aperture stop of the microscope objective, constraining the contour of the imaging beam emitted from the imaging module AA. Therefore, in this specific implementation of the application, it is not necessary to set up other physical aperture stops.
[0045] Using the microscope objective of this application embodiment, configured with the parameters shown in Table 1, and using the ultraviolet light band with a monochromatic light center wavelength of 310 nm and a bandwidth range of ±5 nm, the spot image of the point spread function measurement result is obtained, also known as a dot plot. Figure 2 This is the dot matrix pattern for the 310±5nm band.
[0046] The root mean square (RMS) radius can be used to quantify the concentration of energy distribution in a dot matrix image. A smaller RMS radius indicates more concentrated energy, sharper imaging, and higher optical quality of the system. Please refer to [reference needed]. Figure 2 As shown, in the dot matrix of the 310±5nm band, the RMS radius does not exceed 2 micrometers, indicating that under ultraviolet light irradiation with a center wavelength of 310nm, the microscope objective of this application has a high concentration of light spot energy in the image formed by an ideal point light source. In terms of Gaussian distribution, more than 68% of the energy is contained in a circle with a radius of less than 2 micrometers, resulting in better imaging quality.
[0047] Refer to Figure 7 , Figure 7 As can be seen from the field curvature diagram in the left image and the distortion diagram in the right image, under ultraviolet light irradiation with a center wavelength of 310 nm, the microscope objective of this application has better corrected the field curvature and distortion.
[0048] Figure 3 and Figure 8 The dot plot, field curvature plot, and distortion plot for the 355±5nm band are shown respectively. Figure 3 As shown, under ultraviolet light irradiation with a center wavelength of 355nm, the microscope objective of this embodiment exhibits a high concentration of light spot energy in the image formed by an ideal point light source. In terms of Gaussian distribution, over 68% of the energy is contained within a circle with a radius of less than 2 micrometers, resulting in superior imaging quality. Figure 8 As shown, Figure 8 As can be seen from the field curvature diagram in the left image and the distortion diagram in the right image, under ultraviolet light irradiation with a center wavelength of 355nm, the microscope objective of this application has better corrected the field curvature and distortion.
[0049] Figure 4 and Figure 9 The dot matrix, field curvature, and distortion plots for the 450±10nm band are shown respectively. Figure 4As shown, under visible light illumination with a center wavelength of 450 nm, the microscope objective of this embodiment exhibits a high concentration of light spot energy in the image formed by an ideal point light source. In terms of Gaussian distribution, over 68% of the energy is contained within a circle with a radius of less than 2 micrometers, resulting in superior imaging quality. Figure 9 As shown, Figure 9 As can be seen from the field curvature diagram in the left image and the distortion diagram in the right image, under visible light illumination with a center wavelength of 450nm, the microscope objective of this application has better corrected the field curvature and distortion.
[0050] Figure 5 and Figure 10 The dot matrix, field curvature, and distortion plots for the 520±10nm band are shown respectively. Figure 5 As shown, under visible light illumination with a center wavelength of 520 nm, the microscope objective of this embodiment exhibits a high concentration of light spot energy in the image formed by an ideal point light source. In terms of Gaussian distribution, over 68% of the energy is contained within a circle with a radius of less than 2 micrometers, resulting in superior imaging quality. Figure 10 As shown, Figure 10 As can be seen from the field curvature diagram in the left image and the distortion diagram in the right image, under visible light illumination with a center wavelength of 520nm, the microscope objective of this application has effectively corrected the field curvature and distortion.
[0051] Figure 6 and Figure 11 The dot matrix, field curvature, and distortion plots for the 620±10nm band are shown respectively. Figure 6 As shown, under visible light illumination with a center wavelength of 620 nm, the microscope objective of this embodiment exhibits a high concentration of light spot energy in the image formed by an ideal point light source. In terms of Gaussian distribution, over 68% of the energy is contained within a circle with a radius of less than 2 micrometers, resulting in superior imaging quality. Figure 11 As shown, Figure 11 As can be seen from the field curvature diagram in the left image and the distortion diagram in the right image, under visible light illumination with a center wavelength of 620 nm, the microscope objective of this application has effectively corrected the field curvature and distortion.
[0052] In another aspect of the embodiments of this application, a microscopic imaging system is provided, including a microscope objective as described in any of the foregoing, and a tube lens and a camera disposed on the object side of the microscope objective.
[0053] The microscopic imaging system of this application includes a microscope objective, a telescope, and a camera on the object side of the microscope objective. The imaging beam emitted parallel to the microscope objective is converged by the telescope and imaged on the camera. Because the multiple optical lenses in the microscope objective are made of fused silica and calcium fluoride materials and used in combination, and various optical parameters are reasonably set, the microscope objective can meet the imaging capabilities in the ultraviolet to visible light range, while the emitted imaging beam undergoes coordinated correction of chromatic aberration and aberrations. The emitted imaging beam, after being converged by the telescope, can present a clear image in the camera. By setting the focal length of the telescope, the image image in the camera can provide the required magnification.
[0054] In one feasible embodiment of this application, the magnification of the microscope objective is β=5×, the object-side field of view is φ4mm, the focal length of the tube lens is 200mm, and the parallel beam emitted from the microscope objective is focused by the tube lens and clearly imaged in the camera.
[0055] The formula for calculating the total optical magnification of a microscope imaging system is: Total magnification = Objective lens magnification × (tube lens focal length / eyepiece focal length). Of course, the tube lens provides space to easily integrate other optical elements on the image side of the microscope objective without affecting the infinity optical path of the objective. For example, by adding a beam-splitting prism in the optical path between the imaging module AA and the correction module BB of the microscope objective, the two beams emitted are split and guided to the camera and detector respectively, achieving multi-channel detection.
[0056] The total focal length of the microscope objective is f=40mm, the magnification is β=5×, the object-side field of view is φ4mm, and the focal length of the tube lens is 200mm. Thus, the parallel beam emitted from the microscope objective is converged by the tube lens and clearly presented as a five-fold magnified image in the camera.
[0057] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.
Claims
1. A microscope objective, characterized in that, It includes an imaging module and a correction module arranged in sequence from the object side to the image side. The imaging module includes a first negative lens, a second positive lens, a third negative lens, a fourth positive lens, a fifth negative lens, a sixth positive lens, a seventh negative lens, an eighth positive lens, a ninth negative lens, and a tenth positive lens arranged in sequence. The correction module includes an eleventh positive lens and a twelfth negative lens arranged in sequence. Among them, the optical elements in the imaging module and the correction module are respectively prepared from fused silica or calcium fluoride materials. The total focal length f of the imaging module is 40 mm, and the correction module is used to adjust the aberration to achieve clear imaging at infinity on the image side.
2. The microscope objective according to claim 1, characterized in that, The positive lenses in the imaging module are prepared from calcium fluoride materials, and the negative lenses in the imaging module are prepared from fused silica materials.
3. The microscopic objective lens according to claim 2, wherein The focal length f1 of the first negative lens <0, 0 < |f1 / f| < 1; The focal length f2 of the second positive lens >0, 0.5 < |f2 / f| < 2; The focal length f3 of the third negative lens <0, 2 < |f3 / f| < 5; The focal length f4 of the fourth positive lens >0, 0 < |f4 / f| < 1; The focal length f '5 of the fifth negative lens <0, 0 < |f5 / f| < 1; The focal length f6 of the sixth positive lens >0, 0 < |f6 / f| < 1; The focal length f7 of the seventh negative lens <0, 1 < |f7 / f| < 5; The focal length f8 of the eighth positive lens >0, 1 < |f8 / f| < 2.5; The focal length f9 of the ninth negative lens <0, 1 < |f9 / f| < 4.5; The focal length f of the tenth positive lens 10 > 0, 1 <|f 10 / f| < 3.
5.
4. The microscopic objective lens according to any one of claims 1-3, wherein The focal length f of the eleventh positive lens 11 >0, 2 < |f 11 / f| < 5; The focal length f of the twelfth negative lens 12 <0, 1 < |f 12 / f| < 3.
5. The microscope objective according to claim 4, characterized in that, The eleventh positive lens and the twelfth negative lens are prepared from calcium fluoride materials.
6. The microscope objective according to claim 1, characterized in that, The total working distance WD of the imaging module and the correction module >15 mm, and the numerical aperture NA >0.
26.
7. The microscope objective according to claim 1, characterized in that, There is no cemented surface between the lenses in the imaging module, between the lenses in the correction module, and between the adjacent lenses of the imaging module and the correction module.
8. The microscope objective according to claim 7, characterized in that, The distance between the tenth positive lens of the imaging module and the eleventh positive lens of the correction module is between 1 mm and 30 mm.
9. A microscopic imaging system, characterized in that, It includes the microscopic objective lens according to any one of claims 1-8, and a tube lens and a camera arranged on the object side of the microscopic objective lens.
10. The microscopic imaging system according to claim 9, characterized in that, The magnification β of the microscopic objective lens is 5×, the object field is φ4 mm, the focal length of the tube lens is 200 mm, and the parallel light beam emitted by the microscopic objective lens is converged by the tube lens and clearly imaged in the camera.