Plan-field apochromatic microscope objectives and optical systems

Abstract

This invention provides a plan-field apochromatic microscope objective and optical system, comprising: a first lens group, which includes at least one set of cemented lens groups and at least one independent lens, the cemented lens groups including at least two cemented lenses; the first lens group is used to enlarge the aperture of the beam and reduce the incident angle of the beam to correct part of the spherical aberration and part of the field curvature of the plan-field apochromatic microscope objective; and a second lens group, which includes at least one set of cemented lens groups including at least two cemented lenses; the second lens group is used to converge the beam from the first lens group to correct the residual spherical aberration and residual chromatic aberration of the plan-field apochromatic microscope objective. The plan-field apochromatic microscope objective provided by this invention achieves plan-field apochromatic aberration in the visible to near-infrared light band, and possesses a large numerical aperture and a large field of view, thus realizing a microscope objective that simultaneously achieves high resolution, a large field of view, and a wide spectral band.

Description

Technical Field

[0001] This invention relates to the field of microscope objectives, and particularly to a plan apochromatic microscope objective and optical system. Background Technology

[0002] With the rapid development of science and technology, microscopes have become indispensable optical instruments in fields such as life sciences, medicine, and semiconductor chip inspection. The microscope objective is the core component of a microscope, and its imaging field of view and resolution represent its core performance indicators. Currently, the resolution of microscope objectives has been greatly improved through various technologies, but the imaging field of view is constrained by its inherent design limitations. To compensate for the limited field of view of traditional microscope systems, researchers have proposed acquiring images of each field of view sequentially by moving a sampling platform, and then stitching these images together to obtain the overall field of view of the entire sampled image. However, because the mechanical displacement of the platform can easily affect the changes in the stitched image, this method is prone to losing edge information of each field of view.

[0003] Therefore, significantly expanding the field of view of traditional microscope objectives while maintaining a high numerical aperture is an extremely challenging task. Existing technology includes a two-photon imaging microscope that operates in the near-infrared band and offers an extended field of view greater than 9.5 mm. However, this microscope cannot image in the visible light band, is not suitable for wide bands, and is difficult to integrate with other detection systems. In summary, existing microscope objectives suffer from the technical challenge of simultaneously achieving high resolution, a large field of view, and a wide band. Summary of the Invention

[0004] The purpose of this invention is to provide a plan-field apochromatic microscope objective and optical system that can solve the technical problem that "existing microscope objectives have the difficulty of simultaneously achieving high resolution, large field of view and wide spectral band".

[0005] To solve the above-mentioned technical problems, the present invention is achieved through the following technical solution:

[0006] The present invention provides a plan-field apochromatic microscope objective, comprising: a first lens group near the object side, the first lens group comprising at least one set of cemented lens groups and at least one independent lens, the cemented lens group comprising at least two cemented lenses, the first lens group having a first optical power, the first lens group being used to enlarge the aperture of the beam and reduce the incident angle of the beam, so as to correct part of the spherical aberration and part of the field curvature of the plan-field apochromatic microscope objective;

[0007] The second lens group, located near the image side, includes at least one set of cemented lens groups, each comprising at least two cemented lenses. The second lens group has a second optical power and is used to converge the light beam from the first lens group to correct the residual spherical aberration and residual chromatic aberration of the plan apochromatic microscope objective. The second optical power is greater than the first optical power.

[0008] In this configuration, the lenses in the first lens group and the second lens group are arranged coaxially from the object side to the image side along the optical axis.

[0009] In one embodiment of the present invention, the plan-field apochromatic microscope objective satisfies the following condition:

[0010] 40 < |f1 / f| < 200;

[0011] 2 < |f² / f| < 5;

[0012] Where f represents the focal length of the plan-field apochromatic microscope objective, f1 represents the focal length of the first lens group, and f2 represents the focal length of the second lens group.

[0013] In one embodiment of the present invention, the first lens group includes:

[0014] The first cemented lens group includes a first cemented lens and a second cemented lens arranged sequentially from the object side to the image side along the optical axis;

[0015] The first independent lens is located on the side of the second cemented lens closer to the image side;

[0016] The second independent lens is located on the side of the first independent lens closer to the image side;

[0017] The second cemented lens group is located on the side of the second independent lens closer to the image side. The second cemented lens group includes a third cemented lens and a fourth cemented lens arranged sequentially along the optical axis.

[0018] In one embodiment of the present invention, the first cemented lens is a positive lens, the object side of the first cemented lens is a convex surface, and the image side of the first cemented lens is a concave surface.

[0019] The second cemented lens is a negative lens, the object side of the second cemented lens is convex, and the image side of the second cemented lens is concave.

[0020] The third cemented lens is a positive lens, the object side of the third cemented lens is convex, and the image side of the third cemented lens is convex.

[0021] The fourth cemented lens is a positive lens, the object side of the fourth cemented lens is concave, and the image side of the fourth cemented lens is convex.

[0022] The first independent lens is a negative lens, the object side of the first independent lens is concave, and the image side of the first independent lens is concave.

[0023] The second independent lens is a positive lens, with its object-side surface being concave and its image-side surface being convex.

[0024] In one embodiment of the present invention, the plan-field apochromatic microscope objective satisfies the following condition:

[0025] 0.002≤|φ1|≤0.01, 1.85≤n1≤2.00, 15≤ν1≤25;

[0026] 0.01≤|φ2|≤0.03, 1.50≤n2≤1.70, 50≤ν2≤65;

[0027] 0.003≤|φ3|≤0.01, 1.75≤n3≤1.90, 25≤ν3≤45;

[0028] 0.003≤|φ4|≤0.01, 1.70≤n4≤1.80, 40≤ν4≤45;

[0029] 0.02≤|φ 100 |≤0.04, 1.70≤n 100 ≤1.85, 35≤ν 100 ≤45;

[0030] 0.005≤|φ 200 |≤0.01, 1.80≤n 200 ≤1.90, 15≤ν 200 ≤30;

[0031] Wherein, φ1, n1, and ν1 are the optical power, refractive index, and dispersion of the first cemented lens, respectively; φ2, n2, and ν2 are the optical power, refractive index, and dispersion of the second cemented lens, respectively; φ3, n3, and ν3 are the optical power, refractive index, and dispersion of the third cemented lens, respectively; and φ4, n4, and ν5 are the optical power, refractive index, and dispersion of the fourth cemented lens, respectively. 100 n 100 and ν 100 These are the optical power, refractive index, and dispersion of the first independent lens, respectively, φ 200 n 200 and ν 200 These are the optical power, refractive index, and dispersion of the second independent lens, respectively.

[0032] In one embodiment of the present invention, the second lens group includes:

[0033] The third cemented lens group is located on the side of the fourth cemented lens closer to the image side. The third cemented lens group includes the fifth cemented lens and the sixth cemented lens arranged sequentially along the optical axis.

[0034] The fourth cemented lens group is located on the side of the sixth cemented lens closer to the image side. The fourth cemented lens group includes the seventh cemented lens, the eighth cemented lens, and the ninth cemented lens arranged sequentially along the optical axis.

[0035] The fifth cemented lens group is located on the side of the ninth cemented lens closer to the image side. The fifth cemented lens group includes the tenth cemented lens, the eleventh cemented lens and the twelfth cemented lens arranged sequentially along the optical axis.

[0036] The sixth cemented lens group is located on the side of the twelfth cemented lens closer to the image side. The sixth cemented lens group includes the thirteenth cemented lens and the fourteenth cemented lens arranged sequentially along the optical axis.

[0037] The seventh cemented lens group is located on the side of the fourteenth cemented lens closer to the image side. The seventh cemented lens group includes the fifteenth cemented lens and the sixteenth cemented lens arranged sequentially along the optical axis.

[0038] In one embodiment of the present invention, the fifth cemented lens is a positive lens, the object side of the fifth cemented lens is a convex surface, and the image side of the fifth cemented lens is a convex surface.

[0039] The sixth cemented lens is a negative lens, the object side of the sixth cemented lens is concave, and the image side of the sixth cemented lens is convex.

[0040] The seventh cemented lens is a positive lens, the object side of the seventh cemented lens is convex, and the image side of the seventh cemented lens is convex.

[0041] The eighth cemented lens is a negative lens, the object side of the eighth cemented lens is concave, and the image side of the eighth cemented lens is concave.

[0042] The ninth cemented lens is a positive lens, the object side of the ninth cemented lens is convex, and the image side of the ninth cemented lens is convex.

[0043] The tenth cemented lens is a positive lens, the object side of the tenth cemented lens is convex, and the image side of the tenth cemented lens is convex.

[0044] The eleventh cemented lens is a negative lens, the object side of the eleventh cemented lens is concave, and the image side of the eleventh cemented lens is concave.

[0045] The twelfth cemented lens is a positive lens, the object side of the twelfth cemented lens is convex, and the image side of the twelfth cemented lens is concave.

[0046] The thirteenth cemented lens is a positive lens, the object side of the thirteenth cemented lens is convex, and the image side of the thirteenth cemented lens is convex.

[0047] The fourteenth cemented lens is a negative lens, the object side of the fourteenth cemented lens is concave, and the image side of the fourteenth cemented lens is concave.

[0048] The fifteenth cemented lens is a positive lens, the object side of the fifteenth cemented lens is convex, and the image side of the fifteenth cemented lens is convex.

[0049] The sixteenth cemented lens is a negative lens, and the object-side surface of the sixteenth cemented lens is concave, as is the image-side surface of the sixteenth cemented lens.

[0050] In one embodiment of the present invention, the plan-field apochromatic microscope objective satisfies the following condition:

[0051] 0.005≤|φ5|≤0.02, 1.45≤n5≤1.55, 75≤ν5≤95;

[0052] 0.002≤|φ6|≤0.01, 1.75≤n6≤1.85, 20≤ν6≤35;

[0053] 0.005≤|φ7|≤0.02, 1.45≤n7≤1.55, 75≤ν7≤95;

[0054] 0.01≤|φ8|≤0.03, 1.60≤n8≤1.70, 35≤ν8≤45;

[0055] 0.01≤|φ9|≤0.02, 1.45≤n9≤1.65, 60≤ν9≤75;

[0056] 0.01≤|φ 10 |≤0.02, 1.45≤n 10 ≤1.55, 75≤ν 10 ≤95;

[0057] 0.03≤|φ 11 |≤0.05, 1.60≤n 11 ≤1.70, 35≤ν 11 ≤45;

[0058] 0.01≤|φ 12 |≤0.03, 1.55≤n 12 ≤1.65, 65≤ν 12 ≤75;

[0059] 0.02≤|φ 13 |≤0.04, 1.55≤n 13 ≤1.65, 65≤ν 13 ≤75;

[0060] 0.04≤|φ 14 |≤0.06, 1.60≤n 14 ≤1.70, 35≤ν 14 ≤45;

[0061] 0.06≤|φ 15 |≤0.10, 1.85≤n 15 ≤2.00, 15≤ν 15 ≤25;

[0062] 0.04≤|φ 16 |≤0.07, 1.75≤n 16 ≤1.90, 25≤ν 16 ≤45;

[0063] Wherein, φ5, n5, and ν5 are the optical power, refractive index, and dispersion of the fifth cemented lens, respectively; φ6, n6, and ν6 are the optical power, refractive index, and dispersion of the sixth cemented lens, respectively; φ7, n7, and ν7 are the optical power, refractive index, and dispersion of the seventh cemented lens, respectively; φ8, n8, and ν8 are the optical power, refractive index, and dispersion of the eighth cemented lens, respectively; and φ9, n9, and ν9 are the optical power, refractive index, and dispersion of the ninth cemented lens, respectively. 10 n 10 and ν 10 These are the optical power, refractive index, and dispersion of the tenth cemented lens, respectively, φ 11 n 11 and ν 11 These are the optical power, refractive index, and dispersion of the eleventh cemented lens, respectively, φ 12 n 12 and ν 12 These are the optical power, refractive index, and dispersion of the twelfth cemented lens, respectively, φ 13 n 13 and ν 13 These are the optical power, refractive index, and dispersion of the thirteenth cemented lens, respectively, φ 14 n 14 and ν 14These are the optical power, refractive index, and dispersion of the fourteenth cemented lens, respectively, φ 15 n 15 and ν 15 These are the optical power, refractive index, and dispersion of the fifteenth cemented lens, respectively, φ 16 n 16 and ν 16 These are the optical power, refractive index, and dispersion of the sixteenth cemented lens, respectively.

[0064] In one embodiment of the present invention, the plan apochromatic microscope objective further includes an aperture stop, which is located between the second independent lens and the third cemented lens and is used to limit the size of the imaging beam aperture.

[0065] This application also provides a plan apochromatic microscope objective optical system, including the plan apochromatic microscope objective as described above.

[0066] As described above, the present invention provides a plan-field apochromatic microscope objective and optical system. The first lens group is used to enlarge the aperture of the beam and reduce the incident angle of the beam to correct part of the spherical aberration and part of the field curvature of the plan-field apochromatic microscope objective. The second lens group is used to converge the beam from the first lens group to correct the residual spherical aberration and residual dispersion of the plan-field apochromatic microscope objective. The microscope objective of this application can achieve plan-field apochromatic aberration in the visible to near-infrared light band, and has a large numerical aperture and a large field of view, realizing a microscope objective that simultaneously takes into account high resolution, large field of view and wide band.

[0067] Of course, any product implementing this invention does not necessarily need to achieve all of the advantages described above at the same time. Attached Figure Description

[0068] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0069] Figure 1 This is a schematic diagram of the structure of a plan-field apochromatic microscope objective in one embodiment of the present invention;

[0070] Figure 2 This is a modulation transfer function (MTF) curve of a plan-field apochromatic microscope objective in one embodiment of the present invention;

[0071] Figure 3 This is a dot plot of a plan-field apochromatic microscope objective in one embodiment of the present invention;

[0072] Figure 4 This is a relative distortion curve of a plan-field apochromatic microscope objective in one embodiment of the present invention;

[0073] Figure 5 This is an axial chromatic aberration curve of a plan-field apochromatic microscope objective according to an embodiment of the present invention.

[0074] In the picture:

[0075] 1-First cemented lens, 2-Second cemented lens, 3-First independent lens, 4-Second independent lens, 5-Third cemented lens, 6-Fourth cemented lens, 7-Fifth cemented lens, 8-Sixth cemented lens, 9-Seventh cemented lens, 10-Eighth cemented lens, 11-Ninth cemented lens, 12-Tenth cemented lens, 13-Eleventh cemented lens, 14-Twelfth cemented lens, 15-Thirteenth cemented lens, 16-Fourteenth cemented lens, 17-Fifteenth cemented lens, 18-Sixteenth cemented lens, S-Aperture stop. Detailed Implementation

[0076] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0077] See attached document Figure 1-5 An exemplary description is provided for a plan-field apochromatic microscope objective according to an embodiment of this application.

[0078] A first lens group, located near the object side, includes at least one set of cemented lens groups and at least one independent lens. The cemented lens groups include at least two cemented lenses. The first lens group has a first optical power and is used to enlarge the aperture of the light beam and reduce the incident angle of the light beam to correct part of the spherical aberration and part of the field curvature of the plan-field apochromatic microscope objective. A second lens group, located near the image side, includes at least one set of cemented lens groups and at least two cemented lenses. The second lens group has a second optical power and is used to converge the light beam from the first lens group to correct the residual spherical aberration and residual chromatic aberration of the plan-field apochromatic microscope objective. The second optical power is greater than the first optical power. The lenses in the first and second lens groups are coaxially arranged from the object side to the image side along the optical axis.

[0079] In this embodiment, the plan-field apochromatic microscope objective satisfies the following conditions: 40 < |f1 / f| < 200; 2 < |f2 / f| < 5; where f represents the focal length of the plan-field apochromatic microscope objective, f1 represents the focal length of the first lens group, and f2 represents the focal length of the second lens group. Preferably, the focal length f1 of the first lens group satisfies |f1 / f| = 58.45, and the focal length f2 of the second lens group satisfies |f2 / f| = 2.24. The first lens group has a first optical power, and the second lens group has a second optical power, wherein the second optical power is greater than the first optical power. The first lens group bears the weaker optical power of the objective, and the second lens group bears the main optical power of the objective.

[0080] In this embodiment, the first lens group includes a first cemented lens group, a first independent lens 3, a second independent lens 4, and a second cemented lens group. The first cemented lens group includes a first cemented lens 1 and a second cemented lens 2 arranged sequentially from the object side to the image side along the optical axis. The first independent lens 3 is located on the side of the second cemented lens 2 closer to the image side. The second independent lens 4 is located on the side of the first independent lens 3 closer to the image side. The second cemented lens group is located on the side of the second independent lens 4 closer to the image side. The second cemented lens group includes a third cemented lens 5 and a fourth cemented lens 6 arranged sequentially from the object side to the image side along the optical axis.

[0081] Cemented lenses are lens groups formed by bonding two or more individual lenses together with optical adhesive, while independent lenses are lenses used alone.

[0082] Specifically, see Figure 1 The first cemented lens 1 is a positive lens, with a convex object-side surface and a concave image-side surface; the second cemented lens 2 is a negative lens, with a convex object-side surface and a concave image-side surface; the third cemented lens 5 is a positive lens, with a convex object-side surface and a convex image-side surface; the fourth cemented lens 6 is a positive lens, with a concave object-side surface and a convex image-side surface.

[0083] Specifically, see Figure 1 The first independent lens 3 is a negative lens, with both its object-side surface and image-side surface being concave; the second independent lens 4 is a positive lens, with both its object-side surface and image-side surface being convex.

[0084] For example, the absolute value of the optical power of the first cemented lens 1 is in the range of 0.002≤|φ1|≤0.01; the absolute value of the optical power of the second cemented lens 2 is in the range of 0.01≤|φ2|≤0.03; the absolute value of the optical power of the third cemented lens 5 is in the range of 0.003≤|φ3|≤0.01; and the absolute value of the optical power of the fourth cemented lens 6 is in the range of 0.003≤|φ4|≤0.01.

[0085] Preferably, the absolute value of the optical power of the first cemented lens 1 is 0.0061, the absolute value of the optical power of the second cemented lens 2 is 0.017, the absolute value of the optical power of the third cemented lens 5 is 0.0056, and the absolute value of the optical power of the fourth cemented lens 6 is 0.0051. Those skilled in the art may also choose other values ​​according to the actual situation.

[0086] For example, the absolute value of the optical power of the first independent lens 3 is in the range of: 0.02 ≤ |φ 100 |≤0.04; The absolute value of the optical power of the second independent lens 4 is in the range of: 0.005≤|φ 200 |≤0.01.

[0087] Preferably, the absolute value of the optical power of the first independent lens 3 is 0.025, and the absolute value of the optical power of the second independent lens 4 is 0.0072. Those skilled in the art may also choose other values ​​according to the actual situation.

[0088] For example, the refractive index of the first cemented lens 1 is in the range of 1.85≤n1≤2.00, and the dispersion range is 15≤ν1≤25; the refractive index of the second cemented lens 2 is in the range of 1.50≤n2≤1.70, and the dispersion range is 50≤ν2≤65; the refractive index of the third cemented lens 5 is in the range of 1.75≤n3≤1.90, and the dispersion range is 25≤ν3≤45; the refractive index of the fourth cemented lens 6 is in the range of 1.70≤n4≤1.80, and the dispersion range is 40≤ν4≤45.

[0089] Preferably, the first cemented lens 1 is made of N-SF66 glass material with a refractive index of 1.92 and a dispersion of 20.87; the second cemented lens 2 is made of N-SK2 glass material with a refractive index of 1.61 and a dispersion of 56.65; the third cemented lens 5 is made of N-LASF9 glass material with a refractive index of 1.85 and a dispersion of 32.17; and the fourth cemented lens 6 is made of N-LAK28 glass material with a refractive index of 1.74 and a dispersion of 50.77. Those skilled in the art may also choose other types of materials depending on the specific circumstances.

[0090] For example, the refractive index range of the first independent lens 3 is: 1.70 ≤ n100 ≤1.85, the dispersion range is: 35≤ν 100 ≤45; The refractive index range of the second independent lens 4 is: 1.80≤n 200 ≤1.90, the dispersion range is: 15≤ν 200 ≤30.

[0091] Preferably, the first independent lens 3 is made of N-LAF2 glass material with a refractive index of 1.74 and a dispersion of 44.85, and the second independent lens 4 is made of H-ZF52 glass material with a refractive index of 1.85 and a dispersion of 23.79. Those skilled in the art may also choose other types of materials according to the actual situation.

[0092] The second lens group includes a third cemented lens group, a fourth cemented lens group, a fifth cemented lens group, a sixth cemented lens group, and a seventh cemented lens group; the third cemented lens group is located on the image side of the fourth cemented lens 6, and includes a fifth cemented lens 7 and a sixth cemented lens 8 arranged sequentially along the optical axis; the fourth cemented lens group is located on the image side of the sixth cemented lens 8, and includes a seventh cemented lens 9, an eighth cemented lens 10, and a ninth cemented lens 11 arranged sequentially along the optical axis; the fifth cemented lens group is located on the image side of the ninth cemented lens 6. Lens 11 is located on the image side. The fifth cemented lens group includes a tenth cemented lens 12, an eleventh cemented lens 13, and a twelfth cemented lens 14 arranged sequentially along the optical axis. The sixth cemented lens group is located on the image side of the twelfth cemented lens 14 and includes a thirteenth cemented lens 15 and a fourteenth cemented lens 16 arranged sequentially along the optical axis. The seventh cemented lens group is located on the image side of the fourteenth cemented lens 16 and includes a fifteenth cemented lens 17 and a sixteenth cemented lens 18 arranged sequentially along the optical axis.

[0093] Specifically, see Figure 1The fifth cemented lens 7 is a positive lens, with both its object-side and image-side surfaces being convex. The sixth cemented lens 8 is a negative lens, with both its object-side and image-side surfaces being concave. The seventh cemented lens 9 is a positive lens, with both its object-side and image-side surfaces being convex. The eighth cemented lens 10 is a negative lens, with both its object-side and image-side surfaces being concave. The ninth cemented lens 11 is a positive lens, with both its object-side and image-side surfaces being convex. The tenth cemented lens 12 is a positive lens, with both its object-side and image-side surfaces being convex. The eleventh cemented lens 13 is a negative lens. The object-side surface of the eleventh cemented lens 13 is concave, and the image-side surface of the eleventh cemented lens 13 is also concave; the twelfth cemented lens 14 is a positive lens, with both its object-side surface and image-side surface being convex; the thirteenth cemented lens 15 is a positive lens, with both its object-side surface and image-side surface being convex; the fourteenth cemented lens 16 is a negative lens, with both its object-side surface and image-side surface being concave; the fifteenth cemented lens 17 is a positive lens, with both its object-side surface and image-side surface being convex; and the sixteenth cemented lens 18 is a negative lens, with both its object-side surface and image-side surface being concave.

[0094] For example, the absolute value of the optical power of the fifth cemented lens 7 is in the range of 0.005 ≤ |φ5| ≤ 0.02; the absolute value of the optical power of the sixth cemented lens 8 is in the range of 0.002 ≤ |φ6| ≤ 0.01; the absolute value of the optical power of the seventh cemented lens 9 is in the range of 0.005 ≤ |φ7| ≤ 0.02; the absolute value of the optical power of the eighth cemented lens 10 is in the range of 0.01 ≤ |φ8| ≤ 0.03; the absolute value of the optical power of the ninth cemented lens 11 is in the range of 0.01 ≤ |φ9| ≤ 0.02; and the absolute value of the optical power of the tenth cemented lens 12 is in the range of 0.01 ≤ |φ 10 |≤0.02; The absolute value of the optical power of the eleventh cemented lens 13 is in the range of: 0.03≤|φ 11 |≤0.05; The absolute value of the optical power of the twelfth cemented lens 14 is in the range of: 0.01≤|φ 12 |≤0.03; The absolute value of the optical power of the thirteenth cemented lens 15 is in the range of: 0.02≤|φ 13 |≤0.04; The absolute value of the optical power of the fourteenth cemented lens 16 is in the range of: 0.04≤|φ 14|≤0.06; The absolute value of the optical power of the fifteenth cemented lens 17 is in the range of: 0.06≤|φ 15 |≤0.10; The absolute value of the optical power of the sixteenth cemented lens 18 is in the range of: 0.04≤|φ 16 |≤0.07.

[0095] Preferably, the absolute value of the optical power of the fifth cemented lens 7 is 0.011; the absolute value of the optical power of the sixth cemented lens 8 is 0.0036, the absolute value of the optical power of the seventh cemented lens 9 is 0.011, the absolute value of the optical power of the eighth cemented lens 10 is 0.018, the absolute value of the optical power of the ninth cemented lens 11 is 0.016, the absolute value of the optical power of the tenth cemented lens 12 is 0.014, the absolute value of the optical power of the eleventh cemented lens 13 is 0.038, the absolute value of the optical power of the twelfth cemented lens 14 is 0.021, the absolute value of the optical power of the thirteenth cemented lens 15 is 0.030, the absolute value of the optical power of the fourteenth cemented lens 16 is 0.049, the absolute value of the optical power of the fifteenth cemented lens 17 is 0.076, and the absolute value of the optical power of the sixteenth cemented lens 18 is 0.051. Those skilled in the art may also choose other values ​​according to the actual situation.

[0096] For example, the refractive index range of the fifth cemented lens 7 is 1.45≤n5≤1.55, and the dispersion range is 75≤ν5≤95; the refractive index range of the sixth cemented lens 8 is 1.75≤n6≤1.85, and the dispersion range is 20≤ν6≤35; the refractive index range of the seventh cemented lens 9 is 1.45≤n7≤1.55, and the dispersion range is 75≤ν7≤95; the refractive index range of the eighth cemented lens 10 is 1.60≤n8≤1.70, and the dispersion range is 35≤ν8≤45; the refractive index range of the ninth cemented lens 11 is 1.45≤n9≤1.65, and the dispersion range is 60≤ν9≤75; the refractive index range of the tenth cemented lens 12 is 1.45≤n5≤1.55. 10 ≤1.55, the dispersion range is: 75≤ν 10 ≤95; The refractive index range of the eleventh cemented lens 13 is: 1.60≤n 11 ≤1.70, the dispersion range is: 35≤ν 11 ≤45; The refractive index range of the twelfth cemented lens 14 is: 1.55≤n 12 ≤1.65, the dispersion range is: 65≤ν 12 ≤75; The refractive index range of the thirteenth cemented lens 15 is: 1.55≤n 13 ≤1.65, the dispersion range is: 65≤ν 13 ≤75; The refractive index range of the fourteenth cemented lens 16 is: 1.60≤n 14≤1.70, the dispersion range is: 35≤ν 14 ≤45; The refractive index range of the fifteenth cemented lens 17 is: 1.85≤n 15 ≤2.00, the dispersion range is: 15≤ν 15 ≤25; The refractive index range of the sixteenth cemented lens 18 is: 1.75≤n 16 ≤1.90, the dispersion range is: 25≤ν 16 ≤45.

[0097] Preferably, the fifth cemented lens 7 is made of H-FK61 glass material with a refractive index of 1.50 and a dispersion of 81.59; the sixth cemented lens 8 is made of N-SF6 glass material with a refractive index of 1.81 and a dispersion of 25.36; the seventh cemented lens 9 is made of H-FK61 glass material with a refractive index of 1.50 and a dispersion of 81.59; the eighth cemented lens 10 is made of N-KZFS11 glass material with a refractive index of 1.63 and a dispersion of 42.41; the ninth cemented lens 11 is made of H-ZPK5 glass material with a refractive index of 1.59 and a dispersion of 68.35; the tenth cemented lens 12 is made of H-FK61 glass material with a refractive index of 1.50 and a dispersion of 81.59; and the eleventh cemented lens... Lens 13 is made of N-KZFS11 glass material with a refractive index of 1.63 and a dispersion of 42.41. The twelfth cemented lens 14 is made of H-ZPK5 glass material with a refractive index of 1.59 and a dispersion of 68.35. The thirteenth cemented lens 15 is made of H-ZPK5 glass material with a refractive index of 1.59 and a dispersion of 68.35. The fourteenth cemented lens 16 is made of N-KZFS11 glass material with a refractive index of 1.63 and a dispersion of 42.41. The fifteenth cemented lens 17 is made of N-SF66 glass material with a refractive index of 1.92 and a dispersion of 20.87. The sixteenth cemented lens 18 is made of N-LASF40 glass material with a refractive index of 1.83 and a dispersion of 37.29.

[0098] In this embodiment, the plan apochromatic microscope objective also includes an aperture stop S, which is located between the second independent lens 4 and the third cemented lens 5, and is used to limit the size of the imaging beam aperture.

[0099] In the embodiments of this application, the plan apochromatic microscope objective satisfies the condition: CRA≤1°; where CRA is the incident angle of the principal rays of all fields of view of the plan apochromatic microscope objective on the image side.

[0100] A plan-field apochromatic microscope objective satisfies the condition: DIST ≤ 1%; where DIST is the relative distortion of the plan-field apochromatic microscope objective. Relative distortion is a parameter that measures the degree of image distortion in an optical imaging system. DIST ≤ 1% indicates that the plan-field apochromatic microscope objective has good imaging quality and can maintain high image fidelity and accuracy.

[0101] This application achieves flat-field apochromatic aberration, a large numerical aperture (NA) of 0.5, and a maximum field of view of 8 mm in the visible and near-infrared bands. Specifically, the microscope objective optical system of this application has an effective focal length of f = 25 mm, an image-side field of view of 8 mm, a numerical aperture of 0.5, a working distance of 5 mm, a maximum CRA (corner of incidence) of 0.8° for all principal rays at the image plane, and operates in the visible to near-infrared band, for example, from 480 nm to 920 nm. Furthermore, the RMS wavefront error at the dominant wavelength of 750 nm is less than 0.05λ, resulting in excellent image quality.

[0102] See Figure 1 The surface parameters of all lenses in this application are as follows:

[0103]

[0104]

[0105] See Figures 2-5 The details of the corresponding figures are described in detail:

[0106] See Figure 2 In the figure, the horizontal axis represents spatial frequency in lines pairs per millimeter (lp / mm), and the vertical axis represents the modulation transfer function (MTF). The figure shows that the system's MTF is greater than 0.10 at 1200 lp / mm, close to the diffraction limit, indicating good image quality. The horizontal axis, Spatial Frequency in cycles per mm, is interpreted as spatial frequency and lines pairs per millimeter, while the vertical axis, Modulus of the OTF, is interpreted as the modulation transfer function (MTF).

[0107] See Figure 3 The figure shows that the RMS radius of the dot plot is within the range of the Airy disk radius.

[0108] See Figure 4 The horizontal axis represents relative distortion, and the vertical axis represents the field of view. The figure shows that the relative distortion (DIST) of all fields of view is less than 1%. In the figure, Distortion is interpreted as distortion.

[0109] See Figure 5In the figure, the horizontal axis represents the lateral color difference, and the vertical axis represents the normalized pore size. The figure shows that the axial color difference in this embodiment is less than 2 μm at the 0.7 pore size position, indicating that the axial color difference is well corrected. In the figure, "Millimeters" is interpreted as millimeters, and "Pupil Radius" is interpreted as pore radius.

[0110] This application also provides a plan apochromatic microscope objective optical system, characterized in that it includes the plan apochromatic microscope objective as described above.

[0111] The microscope objective optical system of this application features a higher numerical aperture (NA) and a wider field of view, achieving a large numerical aperture of NA up to 0.5 and a maximum field of view of 8 mm. This microscope objective optical system can be used in fields such as semiconductor defect detection, gene sequencing, and life sciences. This application achieves flat-field apochromatic aberration from the visible to near-infrared light bands, with a chromatic aberration of less than 2 μm, by employing two low-dispersion, low-refractive-index materials (H-FK61 and H-ZPK5 glass materials). All optical element surfaces in this invention are spherical, reducing manufacturing difficulty and saving costs. This application achieves a relatively balanced aberration correction capability for each lens surface by rationally allocating the optical power of the lenses and controlling the incidence angle of the principal rays on each surface, reducing assembly tolerance sensitivity and resulting in a high yield rate for the optical system.

[0112] The embodiments of the present invention disclosed above are merely illustrative of the invention. The embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. A plan apochromatic microscope objective, characterized in that, include: A first lens group, close to the object side, includes at least one set of cemented lens groups and at least one independent lens. The cemented lens group includes at least two cemented lenses. The first lens group has a first optical power. The first lens group is used to enlarge the aperture of the light beam and reduce the incident angle of the light beam to correct part of the spherical aberration and part of the field curvature of the plan-field apochromatic microscope objective. The second lens group, located near the image side, includes at least one set of cemented lens groups, each comprising at least two cemented lenses. The second lens group has a second optical power and is used to converge the light beam from the first lens group to correct the residual spherical aberration and residual chromatic aberration of the plan apochromatic microscope objective. The second optical power is greater than the first optical power. In this configuration, the lenses in the first lens group and the second lens group are coaxially arranged sequentially from the object side to the image side along the optical axis. The first lens group includes a first cemented lens, a second cemented lens, a first independent lens, a second independent lens, a third cemented lens, and a fourth cemented lens arranged in sequence. The second lens group includes a fifth cemented lens, a sixth cemented lens, a seventh cemented lens, an eighth cemented lens, a ninth cemented lens, a tenth cemented lens, an eleventh cemented lens, a twelfth cemented lens, a thirteenth cemented lens, a fourteenth cemented lens, a fifteenth cemented lens, and a sixteenth cemented lens arranged in sequence. The first cemented lens, the third cemented lens, the fourth cemented lens, the second independent lens, the fifth cemented lens, the seventh cemented lens, the ninth cemented lens, the tenth cemented lens, the twelfth cemented lens, the thirteenth cemented lens, and the fifteenth cemented lens are positive lenses; The second cemented lens, the first independent lens, the sixth cemented lens, the eighth cemented lens, the eleventh cemented lens, the fourteenth cemented lens, and the sixteenth cemented lens are negative lenses; The total number of lenses is eighteen.

2. The plan apochromatic microscope objective according to claim 1, characterized in that, The plan-field apochromatic microscope objective satisfies the following condition: 40 < |f1 / f| < 200; 2 < |f² / f| < 5; Where f represents the focal length of the plan-field apochromatic microscope objective, f1 represents the focal length of the first lens group, and f2 represents the focal length of the second lens group.

3. The plan-field apochromatic microscope objective according to claim 1, characterized in that, The first lens group includes: The first cemented lens group includes a first cemented lens and a second cemented lens arranged sequentially from the object side to the image side along the optical axis; The first independent lens is located on the side of the second cemented lens closer to the image side; The second independent lens is located on the side of the first independent lens closer to the image side; The second cemented lens group is located on the side of the second independent lens closer to the image side. The second cemented lens group includes a third cemented lens and a fourth cemented lens arranged sequentially along the optical axis.

4. The plan apochromatic microscope objective according to claim 3, characterized in that, The object-side surface of the first cemented lens is convex, and the image-side surface of the first cemented lens is concave. The object-side surface of the second cemented lens is convex, and the image-side surface of the second cemented lens is concave. The object-side surface of the third cemented lens is convex, and the image-side surface of the third cemented lens is convex. The object-side surface of the fourth cemented lens is concave, and the image-side surface of the fourth cemented lens is convex. The object-side surface of the first independent lens is concave, and the image-side surface of the first independent lens is also concave. The object-side surface of the second independent lens is concave, and the image-side surface of the second independent lens is convex.

5. The plan apochromatic microscope objective according to claim 4, characterized in that, The plan-field apochromatic microscope objective satisfies the following condition: 0.002≤|φ1|≤0.01, 1.85≤n1≤2.00, 15≤ν1≤25; 0.01≤|φ2|≤0.03, 1.50≤n2≤1.70, 50≤ν2≤65; 0.003≤|φ3|≤0.01, 1.75≤n3≤1.90, 25≤ν3≤45; 0.003≤|φ4|≤0.01, 1.70≤n4≤1.80, 40≤ν4≤45; 0.02≤|φ 100 |≤0.04,1.70≤n 100 ≤1.85,35≤ν 100 ≤45; 0.005≤|φ 200 |≤0.01,1.80≤n 200 ≤1.90,15≤ν 200 ≤30; Wherein, φ1, n1, and ν1 are the optical power, refractive index, and dispersion of the first cemented lens, respectively; φ2, n2, and ν2 are the optical power, refractive index, and dispersion of the second cemented lens, respectively; φ3, n3, and ν3 are the optical power, refractive index, and dispersion of the third cemented lens, respectively; and φ4, n4, and ν5 are the optical power, refractive index, and dispersion of the fourth cemented lens, respectively. 100 n 100 and ν 100 These are the optical power, refractive index, and dispersion of the first independent lens, respectively, φ 200 n 200 and ν 200 These are the optical power, refractive index, and dispersion of the second independent lens, respectively.

6. The plan apochromatic microscope objective according to claim 3, characterized in that, The second lens group includes: The third cemented lens group is located on the side of the fourth cemented lens closer to the image side. The third cemented lens group includes a fifth cemented lens and a sixth cemented lens arranged sequentially along the optical axis. The fourth cemented lens group is located on the side of the sixth cemented lens closer to the image side. The fourth cemented lens group includes a seventh cemented lens, an eighth cemented lens, and a ninth cemented lens arranged sequentially along the optical axis. The fifth cemented lens group is located on the side of the ninth cemented lens closer to the image side. The fifth cemented lens group includes a tenth cemented lens, an eleventh cemented lens, and a twelfth cemented lens arranged sequentially along the optical axis. The sixth cemented lens group is located on the side of the twelfth cemented lens closer to the image side. The sixth cemented lens group includes a thirteenth cemented lens and a fourteenth cemented lens arranged sequentially along the optical axis. The seventh cemented lens group is located on the side of the fourteenth cemented lens closest to the image side. The seventh cemented lens group includes a fifteenth cemented lens and a sixteenth cemented lens arranged sequentially along the optical axis.

7. The plan apochromatic microscope objective according to claim 6, characterized in that, The object-side surface of the fifth cemented lens is convex, and the image-side surface of the fifth cemented lens is convex. The object-side surface of the sixth cemented lens is concave, and the image-side surface of the sixth cemented lens is convex. The object-side surface of the seventh cemented lens is convex, and the image-side surface of the seventh cemented lens is convex. The object-side surface of the eighth cemented lens is concave, and the image-side surface of the eighth cemented lens is also concave. The object-side surface of the ninth cemented lens is convex, and the image-side surface of the ninth cemented lens is convex. The object-side surface of the tenth cemented lens is convex, and the image-side surface of the tenth cemented lens is convex. The object side of the eleventh cemented lens is concave, and the image side of the eleventh cemented lens is concave. The object-side surface of the twelfth cemented lens is convex, and the image-side surface of the twelfth cemented lens is concave. The object-side surface of the thirteenth cemented lens is convex, and the image-side surface of the thirteenth cemented lens is convex. The object-side surface of the fourteenth cemented lens is concave, and the image-side surface of the fourteenth cemented lens is also concave. The object-side surface of the fifteenth cemented lens is convex, and the image-side surface of the fifteenth cemented lens is convex. The object-side surface of the sixteenth cemented lens is concave, and the image-side surface of the sixteenth cemented lens is also concave.

8. The plan apochromatic microscope objective according to claim 7, characterized in that, The plan-field apochromatic microscope objective satisfies the following condition: 0.005≤|φ5|≤0.02, 1.45≤n5≤1.55, 75≤ν5≤95; 0.002≤|φ6|≤0.01, 1.75≤n6≤1.85, 20≤ν6≤35; 0.005≤|φ7|≤0.02, 1.45≤n7≤1.55, 75≤ν7≤95; 0.01≤|φ8|≤0.03, 1.60≤n8≤1.70, 35≤ν8≤45; 0.01≤|φ9|≤0.02, 1.45≤n9≤1.65, 60≤ν9≤75; 0.01≤|φ 10 |≤0.02,1.45≤n 10 ≤1.55,75≤ν 10 ≤95; 0.03≤|φ 11 |≤0.05,1.60≤n 11 ≤1.70,35≤ν 11 ≤45; 0.01≤|φ 12 |≤0.03,1.55≤n 12 ≤1.65,65≤ν 12 ≤75; 0.02≤|φ 13 |≤0.04,1.55≤n 13 ≤1.65,65≤ν 13 ≤75; 0.04≤|φ 14 |≤0.06,1.60≤n 14 ≤1.70,35≤ν 14 ≤45; 0.06≤|φ 15 |≤0.10,1.85≤n 15 ≤2.00,15≤ν 15 ≤25; 0.04≤|φ 16 |≤0.07,1.75≤n 16 ≤1.90,25≤ν 16 ≤45; Wherein, φ5, n5, and ν5 are the optical power, refractive index, and dispersion of the fifth cemented lens, respectively; φ6, n6, and ν6 are the optical power, refractive index, and dispersion of the sixth cemented lens, respectively; φ7, n7, and ν7 are the optical power, refractive index, and dispersion of the seventh cemented lens, respectively; φ8, n8, and ν8 are the optical power, refractive index, and dispersion of the eighth cemented lens, respectively; and φ9, n9, and ν9 are the optical power, refractive index, and dispersion of the ninth cemented lens, respectively. 10 n 10 and ν 10 These are the optical power, refractive index, and dispersion of the tenth cemented lens, respectively, φ 11 n 11 and ν 11 These are the optical power, refractive index, and dispersion of the eleventh cemented lens, respectively, φ 12 n 12 and ν 12 These are the optical power, refractive index, and dispersion of the twelfth cemented lens, respectively, φ 13 n 13 and ν 13 These are the optical power, refractive index, and dispersion of the thirteenth cemented lens, respectively, φ 14 n 14 and ν 14 These are the optical power, refractive index, and dispersion of the fourteenth cemented lens, respectively, φ 15 n 15 and ν 15 These are the optical power, refractive index, and dispersion of the fifteenth cemented lens, respectively, φ 16 n 16 and ν 16 These are the optical power, refractive index, and dispersion of the sixteenth cemented lens, respectively.

9. The plan apochromatic microscope objective according to claim 3, characterized in that, The plan-field apochromatic microscope objective also includes an aperture stop, which is located between the second independent lens and the third cemented lens and is used to limit the size of the imaging beam aperture.

10. An optical system for a plan-field apochromatic microscope objectives, characterized in that, Including the plan apochromatic microscope objectives as described in any one of claims 1-9.

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