Flat-field apochromatic microscope objective and optical system

Abstract

The invention provides a flat-field apochromatic microscope objective and an optical system, and the microscope objective comprises a first lens group which comprises at least one cemented lens group and at least one independent lens, the cemented lens group comprises at least two cemented lenses, and the first lens group is used for expanding the aperture of a light beam and reducing the incident angle of the light beam, the partial spherical aberration and partial field curvature of the flat-field apochromatic microscope objective are corrected; the second lens group comprises at least one balsaming lens group, the balsaming lens group comprises at least two balsaming lenses, and the second lens group is used for converging the light beams from the first lens group so as to correct residual spherical aberration and residual chromatic aberration of the flat-field apochromatic microscope objective; according to the flat-field apochromatic microscope objective provided by the invention, flat-field apochromatic in a visible light to near-infrared light wave band range is realized, a large numerical aperture and a large view field range are realized, and the microscope objective with high resolution, a large view field and a wide wave band is realized at the same time.

Description

Technical Field

[0001] The invention relates to the field of microscope objective lenses, and in particular to a plan apochromatic microscope objective lens and an optical system. Background Art

[0002] With the rapid development of science and technology, microscopes have become indispensable optical instruments in the fields of life sciences, medicine, and semiconductor chip testing. The microscope objective is the core component of the microscope, and its imaging field of view and resolution represent the core indicators of the microscope objective. At present, the resolution of the microscope objective has been greatly improved through a variety of technologies, but the imaging field of view of the microscope objective is constrained due to its inherent design limitations. In order to make up for the limited field of view of traditional microscope systems, researchers have proposed to obtain images of each field of view in sequence by moving the sampling platform, and then stitching these images to obtain the comprehensive field of view of the entire sample. However, since the mechanical displacement of the platform easily affects the changes in the stitched image, this method is prone to lose the edge information of each field of view.

[0003] Therefore, it is a very challenging task to significantly expand the field of view of traditional microscope objective lenses while ensuring a high numerical aperture. The prior art has a two-photon imaging microscope, which works in the near-infrared band, has an extended field of view, and a field of view greater than 9.5 mm, but the microscope cannot image in the visible light band, is not suitable for wide bands, and is difficult to be compatible with other detection systems. In summary, the existing microscope objective lenses have the technical problem that it is difficult to simultaneously take into account high resolution, large field of view, and wide band. Summary of the invention

[0004] The purpose of the present invention is to provide a plan apochromatic microscope objective and an optical system, which can solve the technical problem that "existing microscope objective lenses have difficulty in simultaneously taking into account high resolution, large field of view and wide wavelength band".

[0005] In order to solve the above technical problems, the present invention is achieved through the following technical solutions:

[0006] The present invention provides a plan apochromatic microscope objective lens, comprising: a first lens group, close to the object side, the first lens group comprising at least one cemented lens group 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 expand the aperture of a light beam and reduce the incident angle of the light beam, so as to correct partial spherical aberration and partial field curvature of the plan apochromatic microscope objective lens;

[0007] a second lens group, close to the image side, the second lens group includes at least one cemented lens group, the cemented lens group includes at least two cemented lenses, the second lens group has a second optical power, the second lens group 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, wherein the second optical power is greater than the first optical power;

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

[0009] In one embodiment of the present invention, the plan apochromatic microscope objective lens satisfies the conditional formula:

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

[0011] 2<|f2 / f|<5;

[0012] Wherein, f represents the focal length of the plan 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 comprises:

[0014] A first cemented lens group, the first cemented lens group comprising a first cemented lens and a second cemented lens arranged in sequence along the optical axis from the object side to the image side;

[0015] A first independent lens is located on a side of the second cemented lens close to the image side;

[0016] A second independent lens is located on a side of the first independent lens close to the image side;

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

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

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

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

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

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

[0023] The second independent lens is a positive lens, the object side surface of the second independent lens is a concave surface, and the image side surface of the second independent lens is a convex surface.

[0024] In one embodiment of the present invention, the plan apochromatic microscope objective lens satisfies the conditional formula:

[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 respectively the focal power, refractive index and dispersion of the first cemented lens, φ2, n2 and ν2 are respectively the focal power, refractive index and dispersion of the second cemented lens, φ3, n3 and ν3 are respectively the focal power, refractive index and dispersion of the third cemented lens, φ4, n4 and ν5 are respectively the focal power, refractive index and dispersion of the fourth cemented lens, φ 100 、n 100 and ν 100 are the power, refractive index and dispersion of the first independent lens, respectively, 200 、n 200 and ν 200 are respectively the optical power, refractive index and dispersion of the second independent lens.

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

[0033] A third cemented lens group is located on a side of the fourth cemented lens close to the image side, the third cemented lens group comprising the fifth cemented lens and the sixth cemented lens arranged in sequence along the optical axis;

[0034] a fourth cemented lens group, located on a side of the sixth cemented lens close to the image side, the fourth cemented lens group comprising the seventh cemented lens, the eighth cemented lens and the ninth cemented lens arranged in sequence along the optical axis;

[0035] a fifth cemented lens group, located on a side of the ninth cemented lens close to the image side, the fifth cemented lens group comprising the tenth cemented lens, the eleventh cemented lens and the twelfth cemented lens arranged in sequence along the optical axis;

[0036] a sixth cemented lens group, located on a side of the twelfth cemented lens close to the image side, the sixth cemented lens group comprising the thirteenth cemented lens and the fourteenth cemented lens arranged in sequence along the optical axis;

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

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

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

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

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

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

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

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

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

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

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

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

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

[0050] In one embodiment of the present invention, the plan apochromatic microscope objective lens satisfies the conditional formula:

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

[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] The present application also provides a plan-apochromatic microscope objective optical system, comprising the plan-apochromatic microscope objective as described above.

[0066] As described above, the present invention provides a plan-apochromatic microscope objective and an optical system, wherein the first lens group is used to expand the aperture of the light beam and reduce the incident angle of the light beam to correct partial spherical aberration and partial field curvature of the plan-apochromatic microscope objective; the second lens group is used to converge the light beam from the first lens group to correct the residual spherical aberration and residual dispersion of the plan-apochromatic microscope objective. The microscope objective of the present application can achieve plan-apochromatism in the range of visible light to near-infrared light, and has a large numerical aperture and a large field of view, thereby achieving a microscope objective that takes into account high resolution, a large field of view and a wide band at the same time.

[0067] Of course, any product implementing the present invention does not necessarily need to achieve all of the advantages described above at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0068] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for describing the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0069] Figure 1 Schematic diagram of the structure of a plan apochromatic microscope objective lens in one embodiment of the present invention;

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

[0071] Figure 3 is a spot diagram of a plan apochromatic microscope objective in one embodiment of the present invention;

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

[0073] Figure 5 FIG. 4 is a graph showing the axial chromatic aberration of a plan apochromatic microscope objective lens according to an embodiment of the present invention.

[0074] In the figure:

[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 DESCRIPTION

[0076] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0077] Refer to the attached Figure 1-5 A plan apochromatic microscope objective according to an embodiment of the present application is exemplarily described.

[0078] The first lens group is close to the object side, the first lens group includes at least one group 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 focal length, and the first lens group is used to expand 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-apochromatic microscope objective lens; the second lens group is close to the image side, the second lens group includes at least one group of cemented lens groups, the cemented lens group includes at least two cemented lenses, the second lens group has a second optical focal length, and the second lens group 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 lens, wherein the second optical focal length is greater than the first optical focal length; wherein the lenses in the first lens group and the second lens group are coaxially arranged in sequence along the optical axis from the object side to the image side.

[0079] In the embodiment of the present application, the plan apochromatic microscope objective lens satisfies the conditional formula: 40<|f1 / f|<200; 2<|f2 / f|<5; wherein f represents the focal length of the plan apochromatic microscope objective lens, 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 weak optical power of the objective lens, and the second lens group bears the main optical power of the objective lens.

[0080] In an embodiment of the present application, 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 in sequence along the optical axis from the object side to the image side; the first independent lens 3 is located on a side of the second cemented lens 2 close to the image side; the second independent lens 4 is located on a side of the first independent lens 3 close to the image side; the second cemented lens group is located on a side of the second independent lens 4 close to the image side, and the second cemented lens group includes a third cemented lens 5 and a fourth cemented lens 6 arranged in sequence along the optical axis from the object side to the image side.

[0081] A cemented lens is a lens group formed by two or more single lenses bonded together by optical glue, and an independent lens refers to a lens used alone.

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

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

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

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

[0086] For example, the range of the absolute value of the optical power of the first independent lens 3 is: 0.02≤|φ 100 |≤0.04; the range of the absolute value of the optical power of the second independent lens 4 is: 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 select other values ​​according to actual conditions.

[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 is in the range of 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 is in the range of 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 is in the range of 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 is in the range of 40≤ν4≤45.

[0089] Preferably, the first cemented lens 1 uses N-SF66 glass material, whose refractive index is 1.92 and dispersion is 20.87, the second cemented lens 2 uses N-SK2 glass material, whose refractive index is 1.61 and dispersion is 56.65, the third cemented lens 5 uses N-LASF9 glass material, whose refractive index is 1.85 and dispersion is 32.17, and the fourth cemented lens 6 uses N-LAK28 glass material, whose refractive index is 1.74 and dispersion is 50.77. Those skilled in the art may also use other types of materials according to actual conditions.

[0090] For example, the refractive index of the first independent lens 3 is in the range of: 1.70≤n100 ≤1.85, the dispersion range is: 35≤ν 100 ≤45; the refractive index of the second independent lens 4 is in the range of: 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, whose refractive index is 1.74 and dispersion is 44.85, and the second independent lens 4 is made of H-ZF52 glass material, whose refractive index is 1.85 and dispersion is 23.79. Those skilled in the art may also select other types of materials according to actual conditions.

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

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

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

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

[0096] For example, the refractive index of the fifth cemented lens 7 is in the range of 1.45≤n5≤1.55, and the dispersion is in the range of 75≤ν5≤95; the refractive index of the sixth cemented lens 8 is in the range of 1.75≤n6≤1.85, and the dispersion is in the range of 20≤ν6≤35; the refractive index of the seventh cemented lens 9 is in the range of 1.45≤n7≤1.55, and the dispersion is in the range of 75≤ν7≤95; the refractive index of the eighth cemented lens 10 is in the range of 1.60≤n8≤1.70, and the dispersion is in the range of 35≤ν8≤45; the refractive index of the ninth cemented lens 11 is in the range of 1.45≤n9≤1.65, and the dispersion is in the range of 60≤ν9≤75; the refractive index of the tenth cemented lens 12 is in the range of 1.45≤n 10 ≤1.55, the dispersion range is: 75≤ν 10 ≤95; the refractive index of the eleventh cemented lens 13 is in the range of: 1.60≤n 11 ≤1.70, the dispersion range is: 35≤ν 11 ≤45; the refractive index of the twelfth cemented lens 14 is in the range of: 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 of the fourteenth cemented lens 16 is in the range of: 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, whose refractive index is 1.50 and dispersion is 81.59, the sixth cemented lens 8 is made of N-SF6 glass material, whose refractive index is 1.81 and dispersion is 25.36, the seventh cemented lens 9 is made of H-FK61 glass material, whose refractive index is 1.50 and dispersion is 81.59, the eighth cemented lens 10 is made of N-KZFS11 glass material, whose refractive index is 1.63 and dispersion is 42.41, the ninth cemented lens 11 is made of H-ZPK5 glass material, whose refractive index is 1.59 and dispersion is 68.35, the tenth cemented lens 12 is made of H-FK61 glass material, whose refractive index is 1.50 and dispersion is 81.59, and the eleventh cemented lens 13 is made of H-FK61 glass material, whose refractive index is 1.50 and dispersion is 81.59, and the Lens 13 is made of N-KZFS11 glass material, whose refractive index is 1.63 and dispersion is 42.41. The twelfth cemented lens 14 is made of H-ZPK5 glass material, whose refractive index is 1.59 and dispersion is 68.35. The thirteenth cemented lens 15 is made of H-ZPK5 glass material, whose refractive index is 1.59 and dispersion is 68.35. The fourteenth cemented lens 16 is made of N-KZFS11 glass material, whose refractive index is 1.63 and dispersion is 42.41. The fifteenth cemented lens 17 is made of N-SF66 glass material, whose refractive index is 1.92 and dispersion is 20.87. The sixteenth cemented lens 18 is made of N-LASF40 glass material, whose refractive index is 1.83 and dispersion is 37.29.

[0098] In the embodiment of the present application, the plan apochromatic microscope objective further 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 embodiment of the present application, the plan apochromatic microscope objective lens satisfies the conditional formula: CRA≤1°; wherein CRA is the incident angle of the principal light of all fields of view of the plan apochromatic microscope objective lens on the image side.

[0100] Plan apochromatic microscope objective lens meets the conditional formula: DIST ≤ 1%; where DIST is the relative distortion of the plan apochromatic microscope objective lens. Relative distortion is a parameter that measures the degree of image deformation in an optical imaging system. DIST ≤ 1% indicates that the plan apochromatic microscope objective lens has good imaging quality and can maintain high image authenticity and accuracy.

[0101] The present application can achieve flat-field apochromatism, a large numerical aperture of NA reaching 0.5, and a maximum field of view of 8mm in the visible and near-infrared bands. Specifically, the effective focal length of the microscope objective optical system of the present application is f=25mm, the image field of view is 8mm, the numerical aperture is 0.5, the working distance is 5mm, the maximum value of the incident angle CRA of all the main rays of the field of view on the image plane is 0.8°, the working band is visible light to near-infrared light, for example, the working band is 480nm~920nm, and the RMS wavefront error is less than 0.05λ at the main wavelength of 750nm, with good image quality.

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

[0103]

[0104]

[0105] See also Figure 2-Figure 5 Describe the details of the corresponding figures in detail:

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

[0107] See also Figure 3 ,The figure shows that the RMS radius of the spot diagram is within the radius of the Airy disk.

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

[0109] See also Figure 5, the horizontal axis in the figure represents the lateral chromatic aberration, and the vertical axis represents the normalized aperture. The figure shows that the axial chromatic aberration of the embodiment of the present application is less than 2um at the 0.7 aperture position, and the axial chromatic aberration is well corrected. Millimeters in the figure are interpreted as millimeters, and Pupil Radius is interpreted as the aperture radius.

[0110] The present application also provides a plan-apochromatic microscope objective optical system, characterized in that it comprises the plan-apochromatic microscope objective as described above.

[0111] The microscope objective optical system of the present application has a higher numerical aperture (NA) and a larger field of view, and can achieve a large numerical aperture of NA of 0.5 and a maximum field of view of 8mm. The microscope objective optical system can be used in fields such as semiconductor defect detection, gene sequencing, and life and medical sciences. The present application uses two low-dispersion and low-refractive index materials (glass materials of H-FK61 model and H-ZPK5 model) to achieve flat-field apochromatism from visible light to near-infrared light bands, and the chromatic aberration is less than 2um. All optical element surfaces in the present invention are spherical, which reduces the difficulty of processing and saves costs. The present application reasonably distributes the optical power of the lens and controls the incident angle of the main light of each surface, so that the aberration correction ability of each lens surface is relatively balanced, the tolerance sensitivity of the assembly is reduced, and the optical system yield is high.

[0112] The embodiments of the present invention disclosed above are only used to help illustrate the present invention. The embodiments do not describe all the details in detail, nor do they limit the invention to the specific embodiments described. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A plan apochromatic microscope objective lens, characterized in that: include: a first lens group, close to the object side, the first lens group includes at least one cemented lens group 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, and the first lens group is used to expand the aperture of the light beam and reduce the incident angle of the light beam to correct partial spherical aberration and partial field curvature of the plan apochromatic microscope objective; a second lens group, close to the image side, the second lens group includes at least one cemented lens group, the cemented lens group includes at least two cemented lenses, the second lens group has a second optical power, the second lens group 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, wherein the second optical power is greater than the first optical power; Wherein, the lenses in the first lens group and the second lens group are coaxially arranged in sequence along the optical axis from the object side to the image side.

2. The plan apochromatic microscope objective according to claim 1, characterized in that: The plan apochromatic microscope objective meets the conditional formula: 40<|f1 / f|<200; 2<|f2 / f|<5; Wherein, f represents the focal length of the plan 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 apochromatic microscope objective according to claim 1, characterized in that: The first lens group comprises: A first cemented lens group, the first cemented lens group comprising a first cemented lens and a second cemented lens arranged in sequence along the optical axis from the object side to the image side; A first independent lens is located on a side of the second cemented lens close to the image side; A second independent lens is located on a side of the first independent lens close to the image side; The second cemented lens group is located on a side of the second independent lens close to the image side, and the second cemented lens group includes a third cemented lens and a fourth cemented lens arranged in sequence along the optical axis.

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

5. The plan apochromatic microscope objective according to claim 4, characterized in that: The plan apochromatic microscope objective meets the conditional formula: 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 respectively the focal power, refractive index and dispersion of the first cemented lens, φ2, n2 and ν2 are respectively the focal power, refractive index and dispersion of the second cemented lens, φ3, n3 and ν3 are respectively the focal power, refractive index and dispersion of the third cemented lens, φ4, n4 and ν5 are respectively the focal power, refractive index and dispersion of the fourth cemented lens, φ 100 、n 100 and ν 100 are the power, refractive index and dispersion of the first independent lens, respectively, 200 、n 200 and ν 200 are respectively the optical power, refractive index and dispersion of the second independent lens.

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

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

8. The plan apochromatic microscope objective according to claim 7, characterized in that: The plan apochromatic microscope objective meets the conditional formula: 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; Among them, φ5, n5 and ν5 are respectively the focal power, refractive index and dispersion of the fifth cemented lens, φ6, n6 and ν6 are respectively the focal power, refractive index and dispersion of the sixth cemented lens, φ7, n7 and ν7 are respectively the focal power, refractive index and dispersion of the seventh cemented lens, φ8, n8 and ν8 are respectively the focal power, refractive index and dispersion of the eighth cemented lens, φ9, n9 and ν9 are respectively the focal power, refractive index and dispersion of the ninth cemented lens, φ 10 、n 10 and ν 10 are respectively the power, refractive index and dispersion of the tenth cemented lens, φ 11 、n 11 and ν 11 are respectively the power, refractive index and dispersion of the eleventh cemented lens, φ 12 、n 12 and ν 12 are respectively the power, refractive index and dispersion of the twelfth cemented lens, φ 13 、n 13 and ν 13 are respectively the power, refractive index and dispersion of the thirteenth doublet lens, φ 14 、n 14 and ν 14 are respectively the power, refractive index and dispersion of the fourteenth cemented lens, φ 15 、n 15 and ν 15 are respectively the power, refractive index and dispersion of the fifteenth cemented lens, φ 16 、n 16 and ν 16 are respectively the optical power, refractive index and dispersion of the sixteenth cemented lens.

9. The plan apochromatic microscope objective according to claim 3, characterized in that: The plan apochromatic microscope objective lens further comprises 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. A plan apochromatic microscope objective optical system, characterized in that: The invention comprises a plan apochromatic microscope objective as described in any one of claims 1 to 9.

Images