Ultraviolet microscope objective with high numerical aperture

Abstract

The utility model relates to a high-numerical aperture ultraviolet microscope objective, which belongs to the technical field of semiconductor detection microscopic optical systems and comprises a first lens group, a second lens group and a third lens group which are sequentially arranged along an optical axis from an object side to an image side, the first lens group comprises a first lens, a second lens, a third lens and a fourth lens which are sequentially arranged from the object side and have positive focal power; the second lens group comprises a first balsaming lens, a second balsaming lens and a third balsaming lens which are sequentially arranged from the object side; the third lens group comprises a twelfth lens, a thirteenth lens, a fourteenth lens, a fifteenth lens, a sixteenth lens and a seventeenth lens which are sequentially arranged from the object side, the focal power of the twelfth lens, the focal power of the fifteenth lens, the focal power of the sixteenth lens and the focal power of the seventeenth lens are positive, and the focal power of the thirteenth lens and the focal power of the fourteenth lens are negative. Due to the adoption of the lens combination, large view field, high resolution and low distortion are realized, and the microscopic observation requirement can be met.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of semiconductor detection microscopic optical system, and particularly relates to a high numerical aperture ultraviolet microscopic objective. BACKGROUND

[0002] As the basis of modern industry and information industry, semiconductor chip manufacturing is the basis of the basis of modern industry and information industry, and is an important guarantee for economic sustainable development and national security. A very critical parameter in semiconductor manufacturing is the yield rate, and a small change in the yield rate will cause a huge change in cost and profit. Therefore, each process in the semiconductor manufacturing process needs to be monitored.

[0003] Among them, the optical detection technology based on the microscopic optical system is a very important detection method in semiconductor detection, and is widely used in patternless wafer surface defect detection, patterned process surface defect detection and other links. With the development of semiconductor manufacturing technology, the line width of semiconductor manufacturing is getting smaller and smaller, and the resolution requirement of the detection optical system is also higher. At the same time, in order to improve the detection efficiency, the optical system is also required to have a larger field of view.

[0004] As the core component of the microscopic optical system, the objective lens determines the resolution, field of view, working waveband and other aspects of the entire microscopic optical system. It can be said that the development of semiconductor technology has put forward urgent needs for high-resolution and large-field-of-view microscopic objectives. SUMMARY

[0005] In view of the above background technology, the embodiment of the present application provides a high numerical aperture ultraviolet microscopic objective, which has the characteristics of large field of view, high resolution and low distortion, and can be used for microscopic observation.

[0006] The embodiment of the present application provides a high numerical aperture ultraviolet microscopic objective, which comprises:

[0007] A first lens group, a second lens group and a third lens group are arranged in sequence along the optical axis from the object side to the image side;

[0008] The first lens group comprises a first lens, a second lens, a third lens and a fourth lens arranged in sequence from the object side, and the optical power of each of the lenses is positive;

[0009] The second lens group comprises a first cemented lens, a second cemented lens and a third cemented lens arranged in sequence from the object side;

[0010] The third lens group comprises a twelfth lens, a thirteenth lens, a fourteenth lens, a fifteenth lens, a sixteenth lens and a seventeenth lens arranged in sequence from the object side, the optical power of the twelfth lens, the fifteenth lens, the sixteenth lens and the seventeenth lens is positive, and the optical power of the thirteenth lens and the fourteenth lens is negative.

[0011] In some embodiments, the first lens has a radius of curvature of -8.00 to -7.00 mm at the entrance surface S1 and a radius of curvature of -5.00 to -4.00 mm at the exit surface S2.

[0012] The second lens has a radius of curvature of -9.00 to -8.00 mm at the entrance surface S3 and a radius of curvature of -6.00 to -5.00 mm at the exit surface S4.

[0013] The third lens has a radius of curvature of -170.00 to -160.00 mm at the entrance surface S5 and a radius of curvature of -13.00 to -12.00 mm at the exit surface S6.

[0014] The fourth lens has a radius of curvature of 27.00 to 28.00 mm at the entrance surface S7 and a radius of curvature of -220.00 to -210.00 mm at the exit surface S8.

[0015] In some embodiments, the first lens has a thickness of 1.5 to 2.0 mm, the second lens has a thickness of 2.2 to 2.7 mm, the third lens has a thickness of 2.3 to 2.8 mm, and the fourth lens has a thickness of 1.8 to 2.2 mm.

[0016] The first lens, the second lens, the third lens, and the fourth lens have a spacing of 0 to 0.2 mm between adjacent lenses.

[0017] In some embodiments, the first cemented lens includes a fifth lens, a sixth lens, and a seventh lens in the direction from the object side to the image side, the second cemented lens includes an eighth lens and a ninth lens, and the third cemented lens includes a tenth lens and an eleventh lens.

[0018] The fifth lens, the seventh lens, the ninth lens, and the tenth lens have positive optical power, and the sixth lens, the eighth lens, and the eleventh lens have negative optical power.

[0019] In some embodiments, the fifth lens has a radius of curvature of 340.0 to 360.0 mm at the entrance surface S9, a radius of curvature of -12.0 to -11.0 mm at the cemented surface S10 between the fifth lens and the sixth lens, a radius of curvature of 18 to 18.5 mm at the cemented surface S11 between the sixth lens and the seventh lens, and a radius of curvature of -13.5 to -12.5 mm at the exit surface S12 of the seventh lens.

[0020] The curvature radius of the eighth lens incident surface S13 is -85.0 to -80.0 mm, the curvature radius of the cemented surface S14 between the eighth lens and the ninth lens is 16.0 to 17.0 mm, and the curvature radius of the ninth lens exit surface S15 is -32.0 to -28.0 mm;

[0021] The curvature radius of the tenth lens incident surface S16 is 18.0 to 22.0 mm, the curvature radius of the cemented surface S17 between the tenth lens and the eleventh lens is -12.0 to -10.5 mm, and the curvature radius of the eleventh lens exit surface S18 is -32.0 to -28.0 mm.

[0022] In some embodiments, the thickness of the fifth lens is 2.5 to 3.5 mm, the thickness of the sixth lens is 0.5 to 1.5 mm, the thickness of the seventh lens is 4.5 to 5.5 mm, the thickness of the eighth lens is 1.0 to 2.0 mm, the thickness of the ninth lens is 2.5 to 3.5 mm, the thickness of the tenth lens is 3.5 to 4.5 mm, and the thickness of the eleventh lens is 0.5 to 1.5 mm.

[0023] The interval between the fourth lens and the first cemented lens is 0 to 1.0 mm, the interval between the first cemented lens and the second cemented lens is 0 to 0.2 mm, the interval between the second cemented lens and the third cemented lens is 0 to 0.2 mm, and the interval between the third cemented lens and the twelfth lens is 0.3 to 0.8 mm.

[0024] In some embodiments, the curvature radius of the twelfth lens incident surface S20 is 17.0 to 18.0 mm, and the curvature radius of the twelfth lens exit surface S21 is -33.0 to -29.0 mm.

[0025] The curvature radius of the thirteenth lens incident surface S22 is -13.0 to -12.0 mm, and the curvature radius of the thirteenth lens exit surface S23 is 8.0 to 9.0 mm.

[0026] The curvature radius of the fourteenth lens incident surface S24 is -7.0 to -6.0 mm, and the curvature radius of the fourteenth lens exit surface S25 is 21.0 to 25.0 mm.

[0027] The curvature radius of the fifteenth lens incident surface S26 is -10.0 to -9.0 mm, and the curvature radius of the fifteenth lens exit surface S27 is -10.0 to -9.0 mm.

[0028] The curvature radius of the sixteenth lens incident surface S28 is -85.0 to -80.0 mm, and the curvature radius of the sixteenth lens exit surface S29 is -50.0 to -40.0 mm.

[0029] The radius of curvature of the seventeenth lens incident surface S30 is 19.0-23.0mm, and the radius of curvature of the seventeenth lens exit surface S31 is 23.0-26.0mm.

[0030] In some embodiments, the thickness of the twelfth lens is 4.0-5.0mm, the thickness of the thirteenth lens is 7.0-8.0mm, the thickness of the fourteenth lens is 0.5-1.5mm, the thickness of the fifteenth lens is 3.5-4.0mm, the thickness of the sixteenth lens is 1.0-2.0mm, and the thickness of the seventeenth lens is 1.0-2.0mm.

[0031] The interval between the twelfth lens and the thirteenth lens is 0-0.5mm; the interval between the thirteenth lens and the fourteenth lens is 4.0-5.0mm, the interval between the fourteenth lens and the fifteenth lens is 7.0-8.0mm, the interval between the fifteenth lens and the sixteenth lens is 0-0.5mm, and the interval between the sixteenth lens and the seventeenth lens is 0-0.2mm.

[0032] In some embodiments, a diaphragm is arranged between the third cemented lens and the twelfth lens.

[0033] In some embodiments, the numerical aperture of the objective lens is 0.9, the working wavelength range is 365-480nm, the distortion value is not greater than 0.01%, and the MTF cutoff frequency is greater than 2800lp.

[0034] The technical scheme provided in the application has the following beneficial effects:

[0035] The embodiment of the application provides a high-numerical-aperture ultraviolet microscope objective, which comprises a first lens group, a second lens group and a third lens group arranged in sequence along an optical axis from an object side to an image side; the first lens group comprises a first lens, a second lens, a third lens and a fourth lens arranged in sequence from the object side, and the optical powers of the lenses are all positive; the second lens group comprises a first cemented lens, a second cemented lens and a third cemented lens arranged in sequence from the object side; the third lens group comprises a twelfth lens, a thirteenth lens, a fourteenth lens, a fifteenth lens, a sixteenth lens and a seventeenth lens arranged in sequence from the object side, the optical powers of the twelfth lens, the fifteenth lens, the sixteenth lens and the seventeenth lens are all positive, and the optical powers of the thirteenth lens and the fourteenth lens are both negative.

[0036] Due to the adoption of the combination of the positive lens and the negative lens, the light path can be optimized, the field of view can be expanded, the focusing ability of the light can be optimized, the numerical aperture of the microscope objective optical system can be improved, and the resolution can be further improved. The multiple groups of cemented lenses arranged can effectively eliminate chromatic aberration and spherical aberration, further improve the imaging quality, and the positive lens and the negative lens in the third lens group are arranged in intervals, which can play a complementary role and reduce the overall distortion rate, so that the microscope objective optical system of the application can realize large field of view, high resolution and low distortion, and meet the microscopic observation work requirements of the semiconductor industry. BRIEF DESCRIPTION OF DRAWINGS

[0037] In order to more clearly illustrate the technical solutions in the embodiments of the application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative labor.

[0038] Figure 1 The optical structure of the embodiment of the application is shown in the figure.

[0039] Figure 2 The optical transfer function curve of the embodiment of the application is shown in the figure.

[0040] Figure 3 The distortion graph of the embodiment of the application is shown in the figure.

[0041] In the drawings, the components represented by the numbers are listed as follows:

[0042] 100, first lens group; 200, second lens group; 300, third lens group;

[0043] 210, first cemented lens; 220, second cemented lens; 230, third cemented lens;

[0044] 1, first lens; 2, second lens; 3, third lens; 4, fourth lens; 5, fifth lens; 6, sixth lens; 7, seventh lens; 8, eighth lens; 9, ninth lens; 10, tenth lens; 11, eleventh lens; 12, twelfth lens; 13, thirteenth lens; 14, fourteenth lens; 15, fifteenth lens; 16, sixteenth lens; 17, seventeenth lens. DETAILED DESCRIPTION

[0045] To make the purposes, technical solutions, and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work belong to the scope of protection of the present application.

[0046] To address the deficiencies or one of the deficiencies in the foregoing background art, the embodiments of the present application provide a high numerical aperture ultraviolet microscope objective, which has the characteristics of large field of view, high resolution, and low distortion, and can be used for microscopic observation.

[0047] Referring to Figures 1 to 3 The embodiments of the present application provide a high numerical aperture ultraviolet microscope objective, which includes:

[0048] The first lens group 100, the second lens group 200, and the third lens group 300 are sequentially arranged along the optical axis from the object side to the image side.

[0049] The first lens group 100 includes the first lens 1, the second lens 2, the third lens 3, and the fourth lens 4, which are sequentially arranged from the object side and have positive refractive powers.

[0050] The second lens group 200 includes the first cemented lens 210, the second cemented lens 220, and the third cemented lens 230, which are sequentially arranged from the object side.

[0051] The third lens group 300 includes the twelfth lens 12, the thirteenth lens 13, the fourteenth lens 14, the fifteenth lens 15, the sixteenth lens 16, and the seventeenth lens 17, which are sequentially arranged from the object side, and the twelfth lens 12, the fifteenth lens 15, the sixteenth lens 16, and the seventeenth lens 17 have positive refractive powers, and the thirteenth lens 13 and the fourteenth lens 14 have negative refractive powers.

[0052] The first lens group 100 of the high numerical aperture ultraviolet microscope objective in the embodiments of the present application is mainly used to provide refractive power and correct spherical aberration, cooperates with the second lens group 200 and the third lens group 300 to optimize the optical path, expand the field of view, and improve the focusing ability of light rays, thereby improving the numerical aperture of the microscope objective optical system and further improving the resolution. The second lens group 200 is mainly used to correct chromatic aberration, and multiple cemented lenses are used to effectively eliminate chromatic aberration and spherical aberration and further improve the imaging quality. The third lens group 300 is mainly used to correct field curvature, and the positive lens and the negative lens are arranged alternately, which can play a complementary role and reduce the overall distortion rate. Thus, the microscope objective optical system in the present application can realize large field of view, high resolution, and low distortion, and meet the needs of microscopic observation in the semiconductor industry.

[0053] In some optional embodiments, referring to Figures 1 to 3 As shown in the figure, the embodiment of the present application provides a high numerical aperture ultraviolet microscope, in order to further improve the imaging quality, the curvature radius of the first lens 1 incident surface S1 is-7.223mm, the curvature radius of the first lens 1 exit surface S2 is-4.117mm;

[0054] The curvature radius of the second lens 2 incident surface S3 is-8.462mm, and the curvature radius of the second lens 2 exit surface S4 is-5.759mm;

[0055] The curvature radius of the third lens 3 incident surface S5 is-166.269mm, and the curvature radius of the third lens 3 exit surface S6 is-12.392mm;

[0056] The curvature radius of the fourth lens 4 incident surface S7 is 27.852mm, and the curvature radius of the fourth lens 4 exit surface S8 is-216.609mm.

[0057] The thickness of the first lens 1 is 1.86mm, the thickness of the second lens 2 is 2.42mm, the thickness of the third lens 3 is 2.58mm, and the thickness of the fourth lens 4 is 1.99mm;

[0058] In order to further ensure the imaging quality, the interval between the adjacent two lenses in the first lens group 100 is 0.1mm.

[0059] The first lens group 100 of the embodiment of the present application mainly provides optical power and is responsible for spherical aberration correction, including the first lens 1, the second lens 2, the third lens 3 and the fourth lens 4. Among them, the first lens 1 is a concave-convex positive lens, the material refractive index n=1.59, and the Abbe number v=61.3; the second lens 2 is a concave-convex positive lens, the material refractive index n=1.55, and the Abbe number v=71.8; the third lens 3 is a concave-convex positive lens, the material refractive index n=1.77, and the Abbe number v=49.2; the fourth lens 4 is a double-convex positive lens, the material refractive index n=1.73, and the Abbe number v=32.2.

[0060] In some optional embodiments, referring to Figures 1 to 3 As shown in the figure, the embodiment of the present application provides a high numerical aperture ultraviolet microscope, from the object side to the image side, the first cemented lens 210 includes the fifth lens 5, the sixth lens 6 and the seventh lens 7, the second cemented lens 220 includes the eighth lens 8 and the ninth lens 9, and the third cemented lens 230 includes the tenth lens 10 and the eleventh lens 11;

[0061] The optical power of the fifth lens 5, the seventh lens 7, the ninth lens 9 and the tenth lens 10 is positive, and the optical power of the sixth lens 6, the eighth lens 8 and the eleventh lens 11 is negative.

[0062] To further improve the imaging quality, the radius of curvature of the fifth lens 5 incident surface S9 is 349.978 mm, the radius of curvature of the adhesive surface S10 between the fifth lens 5 and the sixth lens 6 is -11.237 mm, the radius of curvature of the adhesive surface S11 between the sixth lens 6 and the seventh lens 7 is 18.185 mm, and the radius of curvature of the seventh lens 7 exit surface S12 is -12.998 mm;

[0063] The radius of curvature of the eighth lens 8 incident surface S13 is -82.594 mm, the radius of curvature of the adhesive surface S14 between the eighth lens 8 and the ninth lens 9 is 16.498 mm, and the radius of curvature of the ninth lens 9 exit surface S15 is -30.678 mm;

[0064] The radius of curvature of the tenth lens 10 incident surface S16 is 19.572 mm, the radius of curvature of the adhesive surface S17 between the tenth lens 10 and the eleventh lens 11 is -11.613 mm, and the radius of curvature of the eleventh lens 11 exit surface S18 is -30.457 mm.

[0065] In some optional embodiments, referring to Figures 1 to 3 As shown, the embodiment of the present application provides a high numerical aperture ultraviolet microscope, the thickness of the fifth lens 5 of the high numerical aperture ultraviolet microscope is 3.07 mm, the thickness of the sixth lens 6 is 1 mm, the thickness of the seventh lens 7 is 5.16 mm, the thickness of the eighth lens 8 is 1.5 mm, the thickness of the ninth lens 9 is 2.95 mm, the thickness of the tenth lens 10 is 3.89 mm, and the thickness of the eleventh lens 11 is 1 mm.

[0066] To further ensure the imaging quality, the interval between the fourth lens 4 and the first adhesive lens 210 is 0.34 mm, the interval between the first adhesive lens 210 and the second adhesive lens 220 is 0.1 mm, the interval between the second adhesive lens 220 and the third adhesive lens 230 is 0.147 mm, and the interval between the third adhesive lens 230 and the twelfth lens 12 is 0.63 mm.

[0067] The second lens group 200 of the embodiment of the present application is mainly responsible for chromatic aberration correction, including the first adhesive lens 210, the second adhesive lens 220 and the third adhesive lens 230. Among them, the first adhesive lens 210 includes the fifth lens 5, the sixth lens 6 and the seventh lens 7. The second adhesive lens 220 includes the eighth lens 8 and the ninth lens 9, and the third adhesive lens 230 includes the tenth lens 10 and the eleventh lens 11.

[0068] The fifth lens 5 is a double convex positive lens, the material refractive index n is 1.71, and the Abbe number v is 53.9; the sixth lens 6 is a double concave negative lens, the material refractive index n is 2.05, and the Abbe number v is 26.9; the seventh lens 7 is a double convex positive lens, the refractive index n is 1.62, and the Abbe number v is 58.2; the eighth lens 8 is a double concave negative lens, the material refractive index n is 1.78, and the Abbe number v is 25.7; the ninth lens 9 is a double convex positive lens, the material refractive index n is 1.95, and the Abbe number v is 18; the tenth lens 10 is a double convex positive lens, the material refractive index n is 1.55, and the Abbe number v is 71.7; and the eleventh lens 11 is a concave-convex negative lens, the material refractive index n is 1.92, and the Abbe number v is 24.

[0069] In some optional embodiments, referring to Figures 1 to 3 The application provides a high numerical aperture ultraviolet microscope, in order to further improve the imaging quality, the curvature radius of the incidence surface S20 of the twelfth lens 12 is 17.468mm, the curvature radius of the exit surface S21 of the twelfth lens 12 is -31.309mm;

[0070] The curvature radius of the incidence surface S22 of the thirteenth lens 13 is -12.232mm, and the curvature radius of the exit surface S23 of the thirteenth lens 13 is 8.499mm;

[0071] The curvature radius of the incidence surface S24 of the fourteenth lens 14 is -6.364mm, and the curvature radius of the exit surface S25 of the fourteenth lens 14 is 23.722mm;

[0072] The curvature radius of the incidence surface S26 of the fifteenth lens 15 is -9.574mm, and the curvature radius of the exit surface S27 of the fifteenth lens 15 is -9.752mm;

[0073] The curvature radius of the incidence surface S28 of the sixteenth lens 16 is -80.641mm, and the curvature radius of the exit surface S29 of the sixteenth lens 16 is -45.642mm;

[0074] The curvature radius of the incidence surface S30 of the seventeenth lens 17 is 20.949mm, and the curvature radius of the exit surface S31 of the seventeenth lens 17 is 24.911mm.

[0075] The thickness of the twelfth lens 12 is 4.52mm, the thickness of the thirteenth lens 13 is 7.36mm, the thickness of the fourteenth lens 14 is 1mm, the thickness of the fifteenth lens 15 is 3.74mm, the thickness of the sixteenth lens 16 is 1.5mm, and the thickness of the seventeenth lens 17 is 1.5mm;

[0076] To further ensure the imaging quality, the interval between the twelfth lens 12 and the thirteenth lens 13 is 0.34mm; the interval between the thirteenth lens 13 and the fourteenth lens 14 is 4.62mm, the interval between the fourteenth lens 14 and the fifteenth lens 15 is 7.71mm, the interval between the fifteenth lens 15 and the sixteenth lens 16 is 0.34mm, and the interval between the sixteenth lens 16 and the seventeenth lens 17 is 0.1mm.

[0077] The third lens group 300 of the embodiment of the application is mainly responsible for field curvature correction, and includes the twelfth lens 12, the thirteenth lens 13, the fourteenth lens 14, the fifteenth lens 15, the sixteenth lens 16 and the seventeenth lens 17. Among them, the twelfth lens 12 is a double-convex positive lens, the material refractive index n = 1.81, and the Abbe number v = 33.3; the thirteenth lens 13 is a double-concave negative lens, the material refractive index n = 1.95, and the Abbe number v = 18; the fourteenth lens 14 is a double-concave negative lens, the material refractive index n = 1.82, and the Abbe number v = 42.7; the fifteenth lens 15 is a concave-convex positive lens, the material refractive index n = 2.00, and the Abbe number v = 29.1; the sixteenth lens 16 is a concave-convex positive lens, the material refractive index n = 1.81, and the Abbe number v = 40.9; and the seventeenth lens 17 is a concave-convex positive lens, the material refractive index n = 1.72, and the Abbe number v = 50.3.

[0078] In some optional embodiments, referring to Figures 1 to 3 As shown in the figure, the embodiment of the application provides a high numerical aperture ultraviolet microscope objective, and a diaphragm is arranged between the third cemented lens 230 and the twelfth lens 12 of the high numerical aperture ultraviolet microscope objective.

[0079] The diaphragm of the embodiment of the application can control the amount of light, adjust the depth of field, reduce aberration, and improve resolution, which can limit the edge light, reduce the influence of chromatic aberration, help to reduce the spherical aberration and coma, and indirectly improve the chromatic aberration correction effect, thereby further improving the imaging quality.

[0080] In some optional embodiments, referring to Figures 1 to 3 As shown in the figure, the embodiment of the application provides a high numerical aperture ultraviolet microscope objective, and the numerical aperture of the objective of the high numerical aperture ultraviolet microscope objective is 0.9, the working waveband is 365-480nm, the focal length is 3mm, the field number is 28mm, the distortion value is not greater than 0.01%, and the MTF cutoff frequency is greater than 2800lp.

[0081] The combination of the positive lens and the negative lens of the microscope objective optical system of the embodiment of the application can effectively correct the distortion, the numerical aperture of the object side of the lens design is as high as 0.9, the light throughput of the lens is large, and the imaging of the observed object is clearer and has higher resolution.

[0082] In addition, the microscope objective optical system employs a transitional wavelength design from ultraviolet to visible light, which can excite fluorescent substances to emit visible light of different colors, creating a sharp contrast and resulting in vivid and diverse observation effects. Specifically, the objective operates in the 365-480nm wavelength range, including 365-400nm and 400-480nm.

[0083] Among them, 365-400nm belongs to near-ultraviolet light (UVA), which is used for fluorescence excitation and ultraviolet imaging. It can excite fluorescent materials to emit visible light, which can then be observed indirectly. 400-480nm belongs to the blue-violet light of visible light, which is used for illumination and display imaging.

[0084] In addition, the combination of positive and negative lenses in the overall optical system of the microscope objective can effectively correct distortion. The lens is designed with an object-side numerical aperture of up to 0.9, which allows for a large amount of light to pass through, resulting in clearer images and higher resolution of the observed objects.

[0085] As shown in Table 1, the specific parameters of the objective lens in this application are as follows (all units are in mm):

[0086]

[0087]

[0088] Referring to Table 1, the aperture of 0.22 mm corresponding to the object plane is the diameter of the optical profile at the object plane, the aperture of 2.5 mm corresponding to the first lens 1 is the diameter of the optical profile at the incident surface S1 of the first lens 1, and the aperture of 6.1 mm corresponding to the seventeenth lens 17 is the diameter of the optical profile at the exit surface S31 of the seventeenth lens 17. Since the magnification is equal to the diameter of the optical profile on the eyepiece side divided by the diameter of the optical profile on the object side, the magnification can be estimated.

[0089] See Figure 2 The optical transfer function (MTF) curves shown indicate that the MTF in both the meridional and sagittal directions at each field of view is close to the diffraction limit, and the MTF at 2800 lp is still greater than 0.3. (See also...) Figure 3 The distortion graph shown has the horizontal axis representing the percentage of distortion and the vertical axis representing the field of view angle. It can be seen that the maximum distortion across the entire field of view is 0.01%.

[0090] In the description of the present application, it should be noted that the terms "upper", "lower", and the like are used for indicating the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. Unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connecting" should be interpreted broadly, for example, can be fixed connection, can also be detachable connection, or integrally connected; can be mechanical connection, can also be electrical connection; can be directly connected, can also be indirectly connected through an intermediate medium, can be the internal communication of two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0091] It should be noted that in the present application, relational terms such as "first" and "second", and the like are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is any such actual relationship or order between these entities or operations. Moreover, the terms "comprising", "including" or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article or apparatus including a series of elements includes not only those elements, but also other elements not explicitly listed, or other elements inherent in such a process, method, article or apparatus. Without more limitations, the element defined by the statement "comprising a" does not exclude the presence of other identical elements in the process, method, article or apparatus including the element.

[0092] The above is only a specific embodiment of the present application, which enables those skilled in the art to understand or implement the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to these embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features applied herein.

Claims

1. A high numerical aperture ultraviolet microscope objective, characterized in that Comprise; a first lens group (100), a second lens group (200) and a third lens group (300) arranged in sequence along the optical axis from the object side to the image side; The first lens group (100) comprises a first lens (1), a second lens (2), a third lens (3) and a fourth lens (4) arranged in sequence from the object side, and the optical power of each of them is positive; The second lens group (200) comprises a first cemented lens (210), a second cemented lens (220) and a third cemented lens (230) arranged in sequence from the object side; The third lens group (300) comprises a twelfth lens (12), a thirteenth lens (13), a fourteenth lens (14), a fifteenth lens (15), a sixteenth lens (16) and a seventeenth lens (17) arranged in sequence from the object side, the optical power of the twelfth lens (12), the fifteenth lens (15), the sixteenth lens (16) and the seventeenth lens (17) is positive, and the optical power of the thirteenth lens (13) and the fourteenth lens (14) is negative.

2. The high numerical aperture ultraviolet microscope objective lens according to claim 1, wherein: The curvature radius of the incident surface S1 of the first lens (1) is -8.0 to -7.0 mm, and the curvature radius of the exit surface S2 of the first lens (1) is -5.0 to -4.0 mm; The curvature radius of the incident surface S3 of the second lens (2) is -9.0 to -8.0 mm, and the curvature radius of the exit surface S4 of the second lens (2) is -6.0 to -5.0 mm; The curvature radius of the incident surface S5 of the third lens (3) is -170.0 to -160.0 mm, and the curvature radius of the exit surface S6 of the third lens (3) is -13.0 to -12.0 mm; The curvature radius of the incident surface S7 of the fourth lens (4) is 27.0 to 28.0 mm, and the curvature radius of the exit surface S8 of the fourth lens (4) is -220.0 to -210.0 mm.

3. The high numerical aperture ultraviolet microscope objective lens according to claim 1, wherein: The thickness of the first lens (1) is 1.5 to 2.0 mm, the thickness of the second lens (2) is 2.2 to 2.7 mm, the thickness of the third lens (3) is 2.3 to 2.8 mm, and the thickness of the fourth lens (4) is 1.8 to 2.2 mm; The interval between any two adjacent lenses in the first lens (1), the second lens (2), the third lens (3) and the fourth lens (4) is 0 to 0.2 mm.

4. The high numerical aperture ultraviolet microscope objective lens according to claim 1, wherein: From the object side to the image side, the first cemented lens (210) comprises a fifth lens (5), a sixth lens (6) and a seventh lens (7), the second cemented lens (220) comprises an eighth lens (8) and a ninth lens (9), and the third cemented lens (230) comprises a tenth lens (10) and an eleventh lens (11). The fifth lens (5), the seventh lens (7), the ninth lens (9) and the tenth lens (10) have positive refractive powers, and the sixth lens (6), the eighth lens (8) and the eleventh lens (11) have negative refractive powers.

5. The high numerical aperture ultraviolet microscope objective according to claim 4, wherein: the fifth lens (5) has a thickness of 2.5-3.5 mm, the sixth lens (6) has a thickness of 0.5-1.5 mm, the seventh lens (7) has a thickness of 4.5-5.5 mm, the eighth lens (8) has a thickness of 1.0-2.0 mm, the ninth lens (9) has a thickness of 2.5-3.5 mm, the tenth lens (10) has a thickness of 3.5-4.5 mm, and the eleventh lens (11) has a thickness of 0.5-1.5 mm. The radius of curvature of the entrance surface S9 of the fifth lens (5) is 340.0-360.0 mm, the radius of curvature of the cemented surface S10 between the fifth lens (5) and the sixth lens (6) is -12.0--11.0 mm, the radius of curvature of the cemented surface S11 between the sixth lens (6) and the seventh lens (7) is 18.0-18.5 mm, and the radius of curvature of the exit surface S12 of the seventh lens (7) is -13.5--12.5 mm. The radius of curvature of the entrance surface S13 of the eighth lens (8) is -85.0--80.0 mm, the radius of curvature of the cemented surface S14 between the eighth lens (8) and the ninth lens (9) is 16.0-17.0 mm, and the radius of curvature of the exit surface S15 of the ninth lens (9) is -32.0--28.0 mm. The radius of curvature of the entrance surface S16 of the tenth lens (10) is 18.0-22.0 mm, the radius of curvature of the cemented surface S17 between the tenth lens (10) and the eleventh lens (11) is -12.0--10.5 mm, and the radius of curvature of the exit surface S18 of the eleventh lens (11) is -32.0--28.0 mm.

5. The high numerical aperture ultraviolet microscope objective according to claim 4, wherein: the fifth lens (5) has a thickness of 2.5-3.5 mm, the sixth lens (6) has a thickness of 0.5-1.5 mm, the seventh lens (7) has a thickness of 4.5-5.5 mm, the eighth lens (8) has a thickness of 1.0-2.0 mm, the ninth lens (9) has a thickness of 2.5-3.5 mm, the tenth lens (10) has a thickness of 3.5-4.5 mm, and the eleventh lens (11) has a thickness of 0.5-1.5 mm. The interval between the fourth lens (4) and the first cemented lens (210) is 0-1.0 mm, the interval between the first cemented lens (210) and the second cemented lens (220) is 0-0.2 mm, the interval between the second cemented lens (220) and the third cemented lens (230) is 0-0.2 mm, and the interval between the third cemented lens (230) and the twelfth lens (12) is 0.3-0.8 mm.

7. The high numerical aperture ultraviolet microscope objective according to claim 1, wherein: the radius of curvature of the entrance surface S20 of the twelfth lens (12) is 17.0-18.0 mm, and the radius of curvature of the exit surface S21 of the twelfth lens (12) is -33.0--29.0 mm. ​ ​ The curvature radius of the thirteenth lens (13) incident surface S22 is -13.0 to -12.0 mm, and the curvature radius of the thirteenth lens (13) exit surface S23 is 8.0 to 9.0 mm; The curvature radius of the fourteenth lens (14) incident surface S24 is -7.0 to -6.0 mm, and the curvature radius of the fourteenth lens (14) exit surface S25 is 21.0 to 25.0 mm; The curvature radius of the fifteenth lens (15) incident surface S26 is -10.0 to -9.0 mm, and the curvature radius of the fifteenth lens (15) exit surface S27 is -10.0 to -9.0 mm; The curvature radius of the sixteenth lens (16) incident surface S28 is -85.0 to -80.0 mm, and the curvature radius of the sixteenth lens (16) exit surface S29 is -50.0 to -40.0 mm; The curvature radius of the seventeenth lens (17) incident surface S30 is 19.0 to 23.0 mm, and the curvature radius of the seventeenth lens (17) exit surface S31 is 23.0 to 26.0 mm.

8. The high numerical aperture ultraviolet microscope objective lens according to claim 1, wherein: The thickness of the twelfth lens (12) is 4.0 to 5.0 mm, the thickness of the thirteenth lens (13) is 7.0 to 8.0 mm, the thickness of the fourteenth lens (14) is 0.5 to 1.5 mm, the thickness of the fifteenth lens (15) is 3.5 to 4.0 mm, the thickness of the sixteenth lens (16) is 1.0 to 2.0 mm, and the thickness of the seventeenth lens (17) is 1.0 to 2.0 mm; The interval between the twelfth lens (12) and the thirteenth lens (13) is 0 to 0.5 mm; the interval between the thirteenth lens (13) and the fourteenth lens (14) is 4.0 to 5.0 mm, the interval between the fourteenth lens (14) and the fifteenth lens (15) is 7.0 to 8.0 mm, the interval between the fifteenth lens (15) and the sixteenth lens (16) is 0 to 0.5 mm, and the interval between the sixteenth lens (16) and the seventeenth lens (17) is 0 to 0.2 mm.

9. The high numerical aperture ultraviolet microscope objective lens according to claim 1, wherein: A diaphragm is arranged between the third cemented lens (230) and the twelfth lens (12).

10. The high numerical aperture ultraviolet microscope objective lens according to claim 1, wherein: The numerical aperture of the objective lens is 0.9, the working waveband is 365-480 nm, the distortion value is not greater than 0.01%, and the MTF cutoff frequency is greater than 2800 lp.

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