A near-infrared light short-wave microscopic magnifying lens

Abstract

The application discloses a kind of short waveband micro-magnifying lens of near-infrared light, including first lens, second lens, third lens, fourth lens, fifth lens, sixth lens and seventh lens sequentially arranged along the direction of light propagation;Wherein, second lens, fourth lens, fifth lens and seventh lens are double cemented lens, along the direction of light propagation, second lens is formed by second negative lens and second positive lens cementing, fourth lens is formed by fourth negative lens and fourth positive lens cementing, fifth lens is formed by fifth negative lens and fifth positive lens cementing, and seventh lens is formed by seventh positive lens and seventh negative lens cementing;First lens is concave-convex positive lens, third lens is double-convex positive lens;Sixth lens is convex-concave negative lens.The above-mentioned lens is from near-infrared waveband 850nm to 1150nm between near-infrared short wave achromatic optical imaging lens, numerical aperture is 6.0, magnification is 5 times, and imaging quality is excellent.

Description

Technical Field

[0001] This invention relates to a near-infrared short-wavelength microscopic magnification lens, belonging to the field of near-infrared lens technology. Background Technology

[0002] The wavelength range of 400–650 nm is called the visible spectrum, which is the band of light visible to the human eye. Near-infrared (NIR) light is the electromagnetic band between visible light (VIS) and mid-infrared (MIR), referring to electromagnetic waves with wavelengths ranging from 780 nm to 2526 nm, which is invisible to the human eye. The near-infrared region is conventionally divided into two areas: near-infrared short-wave (780–1100 nm) and near-infrared long-wave (1100–2526 nm). The near-infrared region was the first non-visible light region discovered by humans.

[0003] Near-infrared (NIR) magnification lenses are suitable for a variety of applications, demonstrating unique advantages in food analysis, agricultural and sideline product analysis, chemical and pharmaceutical analysis, and biomedicine. They also offer significant advantages in semiconductor material quality control, air pollution monitoring, forensic identification, and particularly in petrochemical analysis. NIR light has strong penetrating power, requiring no sample pretreatment. It can penetrate glass and plastic, allowing for direct detection even with packaging. It can be used for non-destructive testing of raw materials and finished products of fruits and vegetables, without requiring any chemical reagents. Compared to conventional analytical methods, it avoids environmental pollution and saves significant reagent costs. NIR spectroscopy includes qualitative and quantitative analysis. Qualitative analysis aims to determine the composition and structure of a substance, while quantitative analysis determines the content of certain components or the quality attributes of a substance. In the same analysis mode, multiple components can be measured simultaneously. For example, in the wheat analysis mode, protein content, moisture content, hardness, sedimentation value, and rapid mixing ratio can be measured simultaneously. The use of the near-infrared band has become increasingly widespread in recent years. Therefore, this invention proposes a near-infrared short-wavelength microscopic magnification lens with excellent imaging quality. Summary of the Invention

[0004] This invention provides a near-infrared short-wavelength microscopic magnification lens, which is a near-infrared short-wavelength achromatic optical imaging lens between 850nm and 1150nm in the near-infrared band, and has excellent imaging performance.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0006] A near-infrared short-wavelength microscopic magnifying lens includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens arranged sequentially along the optical path propagation direction. The second lens, fourth lens, fifth lens, and seventh lens are all cemented doublet lenses. Along the optical path propagation direction, the second lens is formed by cementing a second negative lens and a second positive lens; the fourth lens is formed by cementing a fourth negative lens and a fourth positive lens; the fifth lens is formed by cementing a fifth negative lens and a fifth positive lens; and the seventh lens is formed by cementing a seventh positive lens and a seventh negative lens. The first lens is a concave-convex positive lens, the third lens is a biconvex positive lens, and the sixth lens is a convex-concave negative lens.

[0007] The aperture stop is placed on the first surface (the incident surface of the first lens).

[0008] The aforementioned doublet lens is formed by bonding two lenses together.

[0009] The object under test is located at a finite distance in front of a near-infrared short-wavelength magnifying lens. The infrared detector target surface is located on the image plane, receiving spectral signals within the near-infrared short-wavelength spectral range. This near-infrared short-wavelength magnifying lens has a large numerical aperture and a magnification of 5x.

[0010] The aforementioned lens is a near-infrared short-wave achromatic optical imaging lens operating in the near-infrared short-wave band from 850nm to 1150nm. It receives spectral signals within the near-infrared short-wave spectral range using a near-infrared detector, fully utilizing the information within the short-wave infrared spectrum. This data processing meets the needs of various research and production applications, such as material testing and component analysis. Applications of near-infrared spectroscopy include: measuring the sugar content, organic acids, nitrogen content, and pH value of ethanol in alcoholic beverages; measuring caffeine, sugar, and acidity in beverages (cola, juice, etc.) and identifying genuine juices; measuring protein, total amino acids, and total sugar in condiments (soy sauce, vinegar, etc.); and measuring fatty acids, moisture, and protein in edible oils. Measurement of peroxide value and iodine value for authenticity identification; determination of dry matter, crude protein, crude fiber, digestible energy, metabolizable energy, amino acids, phytic acid, and ethanol content in feed additives; determination of caffeine, moisture, and chlorogenic acid in coffee, and identification of types and origins; determination of the age, amino acids, tea polyphenols, caffeine, moisture, and total nitrogen in tea, quality grading, authenticity identification, and variety identification; identification of raw materials and main active ingredients in pharmaceuticals; measurement of the content of various components in textile blends, reducing sugars in cotton fibers, fiber outer oil, dyeability of fibers, mercerization of cotton fabrics, medullation degree of wool, cotton finishing agents, and cellulose diacetate acetylation value; identification of carpet fiber types; criminal identification of drugs and counterfeit currency, etc.

[0011] An aperture stop is an optical system that limits the size of the imaging beam. Its image in object space is the entrance pupil, and its image in image space is the exit pupil. The aperture stop of an optical system is only effective for objects at a certain position. If the object's position changes, the aperture stop, which originally limited the beam, will lose its function, and the beam may be limited by other apertures. This application places the aperture stop on the first surface of the lens (the entrance surface of the first lens), coinciding with the entrance pupil. This ensures that even if the object distance changes, the entrance pupil remains constant, which is beneficial for stable image quality.

[0012] This application uses a combination of a first material and a second material with different dispersion coefficients to eliminate color difference. The dispersion coefficient of the first material is 50 to 95, and the dispersion coefficient of the second material is 17.9 to 50.

[0013] To improve imaging quality, the refractive index of the first material is 1.430-1.750, and the refractive index of the second material is 1.600-1.950.

[0014] The first material mentioned above is crown glass, and the second material is flint glass.

[0015] Further preferred, the first lens, the second negative lens, the second positive lens, the fourth positive lens, the fifth negative lens, the fifth positive lens, the seventh positive lens, and the seventh negative lens are all made of the second material; the third lens, the fourth negative lens, and the sixth lens are all made of the first material.

[0016] Along the direction of light propagation, the two sides of the first lens are the first lens incident surface and the first lens exit surface, respectively; the two sides of the second lens are the second lens incident surface and the second lens exit surface, respectively, with a cemented surface in the middle; the two sides of the third lens are the third lens incident surface and the third lens exit surface, respectively; the two sides of the fourth lens are the fourth lens incident surface and the fourth lens exit surface, respectively, with a cemented surface in the middle; the two sides of the fifth lens are the fifth lens incident surface and the fifth lens exit surface, respectively, with a cemented surface in the middle; the two sides of the sixth lens are the sixth lens incident surface and the sixth lens exit surface, respectively; and the two sides of the seventh lens are the seventh lens incident surface and the seventh lens exit surface, respectively, with a cemented surface in the middle.

[0017] To further ensure image quality, the radius of curvature of the first lens's incident surface is -25.064±0.02mm, and the radius of curvature of its exit surface is -18.182±0.02mm; the radius of curvature of the second lens's incident surface is -34.08±0.02mm, the radius of curvature of its intermediate cemented surface is 109.52±0.02mm, and the radius of curvature of its exit surface is -34.23±0.02mm; the radius of curvature of the third lens's incident surface is 113.818±0.02mm, and the radius of curvature of its exit surface is -32.57±0.02mm; the radius of curvature of the fourth lens's incident surface is -28.03±0.02mm, and the radius of curvature of its intermediate cemented surface is 98.63±0.02mm. The radius of curvature of the fourth lens's exit surface is -74.04±0.02mm; the radius of curvature of the fifth lens's incident surface is 188.41±0.02mm, the radius of curvature of the fifth lens's intermediate cemented surface is 27.57±0.02mm, and the radius of curvature of the fifth lens's exit surface is -156.02±0.02mm; the radius of curvature of the sixth lens's incident surface is -34.295±0.02mm, and the radius of curvature of the sixth lens's exit surface is -83.431±0.02mm; the radius of curvature of the seventh lens's incident surface is 36.214±0.02mm, the radius of curvature of the seventh lens's intermediate cemented surface is 271.87±0.02mm, and the radius of curvature of the seventh lens's exit surface is 19.665±0.02mm.

[0018] Note: As Figure 1 As shown, if light propagates from left to right, the radius of curvature is positive if the center of curvature of the radius of curvature is to the right of the vertex of the surface; and negative if the center of curvature of the radius of curvature is to the left of the vertex of the surface.

[0019] To better correct on-axis aberrations, the incident surface of the sixth lens is an aspherical surface. The aspherical surface uses an even-order non-surface equation;

[0020]

[0021] The meanings of the quantities in the equation are as follows:

[0022] Z(Y) is the lens dropout of the aspherical surface along the optical axis;

[0023] R is the radius of curvature of the lens;

[0024] Y is the half-aperture of the lens perpendicular to the optical axis;

[0025] K is the conic coefficient;

[0026] A, B, C, D, and E are aspherical coefficients.

[0027] The near-infrared short-wavelength microscope magnifying lens of this application has a relatively large numerical aperture of 0.6, belonging to a small field-of-view, large-aperture optical system. For small field-of-view, large-aperture systems, due to the small field of view, off-axis aberrations are not significant, and the main aberrations considered are aperture-related aberrations such as spherical aberration, sine aberration, and chromatic aberration. This application uses four sets of cemented lenses to correct chromatic aberration; it uses aspherical lenses to correct spherical aberration, and the combination of multiple lenses compensates for each other to reduce system spherical aberration and sine aberration.

[0028] To better ensure imaging quality, the aforementioned near-infrared short-wavelength microscopic magnifying lens has the following center distances: 13.008±0.002mm; 0.60±0.02mm between the first and second lenses; 0.30±0.02mm between the second and third lenses; 12.55±0.02mm between the third and fourth lenses; 66.05±0.02mm between the fourth and fifth lenses; 17.75±0.02mm between the fifth and sixth lenses; 79.65±0.02mm between the sixth and seventh lenses; and 20.548±0.02mm between the seventh lens and the image plane.

[0029] The center thickness of the first lens is 7.85±0.02mm; the center thickness of the second lens is 10.35±0.02mm, of which the center thickness of the second negative lens is 2.35±0.02mm and the center thickness of the second positive lens is 8.0±0.02mm; the center thickness of the third lens is 14.8±0.02mm; and the center thickness of the fourth lens is 22.65±0.02mm, of which the center thickness of the fourth negative lens is 6.7±0.02mm and the center thickness of the fourth positive lens is 15. The center thickness of the fifth lens is 16.9±0.02mm, of which the center thickness of the fifth negative lens is 2.0±0.02mm and the center thickness of the fifth positive lens is 14.90±0.02mm; the center thickness of the sixth lens is 5.0±0.02mm; the center thickness of the seventh lens is 29.40±0.02mm, of which the center thickness of the seventh positive lens is 15.0±0.02mm and the center thickness of the seventh negative lens is 14.40±0.02mm.

[0030] The aforementioned near-infrared short-wavelength microscopic magnifying lens uses a wavelength of 850nm-1150nm, a numerical aperture of 6.0, and a magnification of 5x.

[0031] Any techniques not mentioned in this invention are based on existing technologies.

[0032] This invention relates to a near-infrared short-wavelength microscopic magnifying lens with a relatively large numerical aperture of 0.6, belonging to a small field-of-view, large-aperture optical system. For such systems, due to the small field of view, off-axis aberrations are not significant, and the main considerations are aperture-related aberrations such as spherical aberration, sine aberration, and positional chromatic aberration. This invention employs four sets of cemented lenses to effectively correct positional chromatic aberration and aspherical lenses to effectively correct spherical aberration. Simultaneously, the combination of multiple lenses mutually compensates for each other, reducing system spherical and sine aberrations. The system achieves a good balance between spectral chromatic aberration, on-axis and off-axis aberrations, resulting in a better optical transfer function. The wavelength range is 850nm-1150nm, with a magnification of 5x. Furthermore, the aperture stop is placed on the first surface of the lens, coinciding with the entrance pupil. This ensures that even with changes in object distance, the entrance pupil remains constant, contributing to stable image quality. Attached Figure Description

[0033] Figure 1 This is a diagram of the optical system of the near-infrared short-wavelength microscopic magnification lens of the present invention;

[0034] Figure 2 This is an aberration curve diagram of a near-infrared short-wavelength microscopic magnification lens in an embodiment of the present invention;

[0035] Figure 3 This is a diffusion pattern of a near-infrared short-wavelength microscopic lens in an embodiment of the present invention.

[0036] Figure 4 This is a field curvature and distortion diagram of a near-infrared short-wavelength microscopic magnification lens in an embodiment of the present invention;

[0037] Figure 5 This is the MTF diagram of the near-infrared short-wave band microscopic magnification lens in an embodiment of the present invention;

[0038] Figure 1 In the diagram, 1 is the first lens, 2 is the second lens, 3 is the third lens, 4 is the fourth lens, 5 is the fifth lens, 6 is the sixth lens, and 7 is the seventh lens. Detailed Implementation

[0039] To better understand the present invention, the following embodiments further illustrate the content of the present invention, but the content of the present invention is not limited to the following embodiments.

[0040] Example

[0041] like Figure 1As shown, a near-infrared short-wavelength microscopic magnifying lens, arranged sequentially from left to right along the optical path, comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens. The aperture stop is located on the incident surface (first surface) of the first lens. The second, fourth, fifth, and seventh lenses are all cemented doublet lenses. The second lens is formed by cementing a second negative lens and a second positive lens; the fourth lens is formed by cementing a fourth negative lens and a fourth positive lens; the fifth lens is formed by cementing a fifth negative lens and a fifth positive lens; and the seventh lens is formed by cementing a seventh positive lens and a seventh negative lens. The first lens is a concave-convex positive lens; the third lens is a biconvex positive lens; and the sixth lens is a negative-convex-concave negative lens. The object being measured is located at a finite distance in front of the near-infrared short-wavelength microscopic magnifying lens.

[0042] Along the direction of light propagation from left to right, the two sides of the first lens are, in order, the first lens incident surface S1 and the first lens exit surface S2; the two sides of the second lens are, in order, the second lens incident surface S3 and the second lens exit surface S5, with a second lens cemented surface S4 in the middle; the two sides of the third lens are, in order, the third lens incident surface S6 and the third lens exit surface S7; the two sides of the fourth lens are, in order, the fourth lens incident surface S8 and the fourth lens exit surface S10, with a fourth lens cemented surface S9 in the middle; the two sides of the fifth lens are, in order, the fifth lens incident surface S11 and the fifth lens exit surface S13, with a fifth lens cemented surface S12 in the middle; the two sides of the sixth lens are, in order, the sixth lens incident surface S14 and the sixth lens exit surface S15; the two sides of the seventh lens are, in order, the seventh lens incident surface S16 and the seventh lens exit surface S18, with a seventh lens cemented surface S17 in the middle. The radius of curvature of the incident surface of the first lens is -25.064 mm, and the radius of curvature of the exit surface of the first lens is -18.182 mm; the radius of curvature of the incident surface of the second lens is -34.08 mm, the radius of curvature of the cemented surface of the second lens is 109.52 mm, and the radius of curvature of the exit surface of the second lens is -34.23 mm; the radius of curvature of the incident surface of the third lens is 113.818 mm, and the radius of curvature of the exit surface of the third lens is -32.57 mm; the radius of curvature of the incident surface of the fourth lens is -28.03 mm, and the radius of curvature of the cemented surface of the fourth lens is 98.63 mm. The radius of curvature of the exit surface of the fourth lens is -74.04 mm; the radius of curvature of the incident surface of the fifth lens is 188.41 mm, the radius of curvature of the cemented surface in the middle of the fifth lens is 27.57 mm, and the radius of curvature of the exit surface of the fifth lens is -156.02 mm; the radius of curvature of the incident surface of the sixth lens is -34.295 mm, and the radius of curvature of the exit surface of the sixth lens is -83.431 mm; the radius of curvature of the incident surface of the seventh lens is 36.214 mm, the radius of curvature of the cemented surface in the middle of the seventh lens is 271.87 mm, and the radius of curvature of the exit surface of the seventh lens is 19.665 mm.

[0043] The object distance of the aforementioned lenses is 13.008 mm; the center-to-center distance between the first and second lenses is 0.60 mm; the center-to-center distance between the second and third lenses is 0.30 mm; the center-to-center distance between the third and fourth lenses is 12.55 mm; the center-to-center distance between the fourth and fifth lenses is 66.05 mm; the center-to-center distance between the fifth and sixth lenses is 17.75 mm; the center-to-center distance between the sixth and seventh lenses is 79.65 mm; and the center-to-center distance between the seventh lens and the image plane is 20.548 mm.

[0044] The center thickness of the first lens is 7.85 mm; the center thickness of the second lens is 10.35 mm, of which the center thickness of the second negative lens is 2.35 mm and the center thickness of the second positive lens is 8.0 mm; the center thickness of the third lens is 14.8 mm; the center thickness of the fourth lens is 22.65 mm, of which the center thickness of the fourth negative lens is 6.7 mm and the center thickness of the fourth positive lens is 15.95 mm; the center thickness of the fifth lens is 16.9 mm, of which the center thickness of the fifth negative lens is 2.0 mm and the center thickness of the fifth positive lens is 14.90 mm; the center thickness of the sixth lens is 5.0 mm; and the center thickness of the seventh lens is 29.40 mm, of which the center thickness of the seventh positive lens is 15.0 mm and the center thickness of the seventh negative lens is 14.40 mm. The first, second negative, second positive, fourth positive, fifth negative, fifth positive, seventh positive, and seventh negative lenses are all made of crown glass; the third, fourth negative, and sixth lenses are all made of flint glass.

[0045] Table 1 shows the parameters of the optical components.

[0046]

[0047]

[0048] The sixth incident surface is an aspherical surface, and the aspherical surface uses an even-order non-surface equation;

[0049]

[0050] The meanings of the quantities in the equation are as follows:

[0051] Z(Y) is the lens dropout of the aspherical surface along the optical axis;

[0052] R is the radius of curvature of the lens;

[0053] Y is the half-aperture of the lens perpendicular to the optical axis;

[0054] K is the conic coefficient;

[0055] A, B, C, D, and E are aspherical coefficients.

[0056] Table 2 shows the aspheric coefficients in this example.

[0057]

[0058] The optical system parameters of the aforementioned near-infrared short-wavelength microscopic magnification lens are as follows:

[0059] Magnification: 5x; Numerical aperture: 0.6; Wavelength: 850nm-1150nm; Image size: Back focal length: 20.54mm; Lens length: 304mm; Object-image conjugate distance: 317.4mm.

[0060] The aforementioned lens is an optical imaging microscopic magnification lens operating in the near-infrared band from 850nm to 1150nm. It receives spectral signals within the near-infrared short-wavelength spectral range, fully utilizing and processing information within this range to meet various research and production needs. Applications include food analysis, agricultural and sideline product analysis and testing, chemical and pharmaceutical analysis, and biomedical applications.

[0061] The aforementioned lens employs a combination of two materials with different dispersion coefficients for achromatic design. The aperture stop is placed on the first surface of the lens, coinciding with the entrance pupil. This ensures that the entrance pupil remains constant even with changes in object distance, contributing to stable image quality. This near-infrared short-wavelength micromagnifier has a relatively large numerical aperture of 0.6, classifying it as a small field-of-view, large-aperture optical system. For such systems, the off-axis aberrations are less pronounced due to the small field of view; therefore, aperture-related aberrations are primarily considered, such as spherical aberration, sinusoidal aberration, and positional chromatic aberration. The aforementioned lens uses three sets of cemented lenses to correct positional chromatic aberration and aspherical lenses to correct spherical aberration. Simultaneously, the combination of multiple lenses mutually compensates for each other, reducing system spherical and sinusoidal aberrations. The system achieves a good balance between spectral chromatic aberration, on-axis aberrations, and off-axis aberrations, resulting in a good optical transfer function. This invention's near-infrared short-wavelength micromagnifier meets practical application requirements.

[0062] Depend on Figure 2 The aberration curves show that the lens has effectively corrected various aberrations, with the maximum on-axis aberration at approximately 6.1 μm, and the maximum off-axis meridional and sagittal aberrations at approximately 20 μm. Figure 3 The dispersion pattern shows that the system exhibits a good balance between broad spectral chromatic aberration, on-axis and off-axis aberrations, and minimal coma. The on-axis dispersion radius (RMS) is approximately 2 micrometers, while the maximum off-axis dispersion radius (RMS) is approximately 9 micrometers. Figure 4 The field curvature and distortion maps show that a field curvature within 0.18 mm and distortion less than 0.25% minimize image quality errors in the center and edges of the system; Figure 5 The MTF curve shows that the optical transfer function of the optical system is greater than 0.35@100lp / mm across the entire field of view. In summary, the quality of the aforementioned infrared short-wavelength microscopic magnification lens fully meets the requirements for practical use.

Claims

1. A near-infrared short-wavelength microscopic magnifying lens, characterized in that: It includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens arranged sequentially along the direction of light propagation; wherein, the second lens, the fourth lens, the fifth lens, and the seventh lens are all cemented doublet lenses. Along the direction of light propagation from left to right, the second lens is formed by cementing a second negative lens and a second positive lens, the fourth lens is formed by cementing a fourth negative lens and a fourth positive lens, the fifth lens is formed by cementing a fifth negative lens and a fifth positive lens, and the seventh lens is formed by cementing a seventh positive lens and a seventh negative lens; the first lens is a concave-convex positive lens, the third lens is a biconvex positive lens, and the sixth lens is a convex-concave negative lens; The radius of curvature of the incident surface of the first lens is -25.064±0.02mm, and the radius of curvature of the exit surface of the first lens is -18.182±0.02mm; the radius of curvature of the incident surface of the second lens is -34.08±0.02mm, the radius of curvature of the cemented surface of the second lens is 109.52±0.02mm, and the radius of curvature of the exit surface of the second lens is -34.23±0.02mm; the radius of curvature of the incident surface of the third lens is 113.818±0.02mm, and the radius of curvature of the exit surface of the third lens is -32.57±0.02mm; the radius of curvature of the incident surface of the fourth lens is -28.03±0.02mm, and the radius of curvature of the cemented surface of the fourth lens is 98.63±0.02mm. The radius of curvature of the exit surface of the fourth lens is -74.04±0.02mm; the radius of curvature of the incident surface of the fifth lens is 188.41±0.02mm, the radius of curvature of the cemented surface in the middle of the fifth lens is 27.57±0.02mm, and the radius of curvature of the exit surface of the fifth lens is -156.02±0.02mm; the radius of curvature of the incident surface of the sixth lens is -34.295±0.02mm, and the radius of curvature of the exit surface of the sixth lens is -83.431±0.02mm; the radius of curvature of the incident surface of the seventh lens is 36.214±0.02mm, the radius of curvature of the cemented surface in the middle of the seventh lens is 271.87±0.02mm, and the radius of curvature of the exit surface of the seventh lens is 19.665±0.02mm.

2. The near-infrared short-wavelength microscopic magnifying lens as described in claim 1, characterized in that: Each lens uses a combination of a first material and a second material with different dispersion coefficients to achromaticly reduce the color. The first material has a dispersion coefficient of 50 to 95, and the second material has a dispersion coefficient of 17.9 to 50.

3. The near-infrared short-wavelength microscopic magnifying lens as described in claim 2, characterized in that: The refractive index of the first material is 1.430-1.750, and the refractive index of the second material is 1.600-1.

950.

4. The near-infrared short-wavelength microscopic magnifying lens as described in claim 3, characterized in that: The first material is crown glass, and the second material is flint glass.

5. The near-infrared short-wavelength microscopic magnifying lens as described in claim 4, characterized in that: The first lens, the second negative lens, the second positive lens, the fourth positive lens, the fifth negative lens, the fifth positive lens, the seventh positive lens, and the seventh negative lens are all made of the second material; the third lens, the fourth negative lens, and the sixth lens are all made of the first material.

6. The near-infrared short-wavelength microscopic magnifying lens as described in any one of claims 1-5, characterized in that: The object distance is 13.008±0.002mm; the center-to-center distance between the first and second lenses is 0.60±0.02mm; the center-to-center distance between the second and third lenses is 0.30±0.02mm; the center-to-center distance between the third and fourth lenses is 12.55±0.02mm; the center-to-center distance between the fourth and fifth lenses is 66.05±0.02mm; the center-to-center distance between the fifth and sixth lenses is 17.75±0.02mm; the center-to-center distance between the sixth and seventh lenses is 79.65±0.02mm; and the center-to-center distance between the seventh lens and the image plane is 20.548±0.02mm.

7. The near-infrared short-wavelength microscopic magnifying lens as described in any one of claims 1-5, characterized in that: The center thickness of the first lens is 7.85±0.02mm; the center thickness of the second lens is 10.35±0.02mm, of which the center thickness of the second negative lens is 2.35±0.02mm and the center thickness of the second positive lens is 8.0±0.02mm; the center thickness of the third lens is 14.8±0.02mm; and the center thickness of the fourth lens is 22.65±0.02mm, of which the center thickness of the fourth negative lens is 6.7±0.02mm and the center thickness of the fourth positive lens is 15. The center thickness of the fifth lens is 16.9±0.02mm, of which the center thickness of the fifth negative lens is 2.0±0.02mm and the center thickness of the fifth positive lens is 14.90±0.02mm; the center thickness of the sixth lens is 5.0±0.02mm; the center thickness of the seventh lens is 29.40±0.02mm, of which the center thickness of the seventh positive lens is 15.0±0.02mm and the center thickness of the seventh negative lens is 14.40±0.02mm.

8. The near-infrared short-wavelength microscopic magnifying lens as described in any one of claims 1-5, characterized in that: The aperture stop is located on the incident surface of the first lens; the incident surface of the sixth lens is aspherical.

9. The near-infrared short-wavelength microscopic magnifying lens as described in any one of claims 1-5, characterized in that: The wavelength used is in the near-infrared shortwave band of 850nm-1150nm, the numerical aperture is 0.6, and the magnification is 5x.

Images