Ultra-wide-range white light confocal dispersion lens and white light confocal measurement system

Abstract

The invention discloses an ultra-wide-range white light confocal dispersion lens and a white light confocal measurement system, and the ultra-wide-range white light confocal dispersion lens comprises a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens which are sequentially and coaxially arranged along light incidence, the third lens and the fourth lens form a second balsaming lens, and the fifth lens and the sixth lens form a third balsaming lens. The chromatic dispersion lens has the chromatic dispersion range of 74 mm, the rear working distance covers 113 mm to 187 mm, the total length of a system is 152.122 mm, and the chromatic dispersion lens is compact in structure, convenient to assemble, high in use value and wide in application adaptability.

Description

Technical Field

[0001] The present application relates to the field of optical measurement technology, and in particular to an ultra-large-range white light confocal dispersion lens and a white light confocal measurement system. Background Art

[0002] The white light confocal measurement system is a high-precision photoelectric measurement technology that uses the dispersion phenomenon and the confocal microscopy principle to accurately detect the displacement of an object. The system can accurately measure tiny displacements by analyzing the relationship between the wavelength change of the reflected light on the surface of the object and the focal position, and is suitable for micro- and nano-level displacement detection. Compared with the traditional laser confocal system, the white light confocal system has a wider wavelength range and higher measurement accuracy, and can provide non-contact, fast, and non-destructive displacement measurement. It is widely used in precision measurement, material testing, and micro-displacement analysis.

[0003] The core component of the white light confocal measurement system is the white light confocal dispersive lens. The performance of the dispersive lens directly affects the measurement performance of the system. At present, there has been a lot of progress in the research of white light confocal dispersive lenses, but there is still a certain gap in the demand for ultra-large-range measurement range, so it cannot meet some application scenarios of large displacement measurement. Summary of the invention

[0004] In view of this, the embodiment of the present application provides a white light confocal dispersion lens and a white light confocal measurement system with an ultra-large range, which can meet the demand for high-precision measurement in an ultra-large measurement range. The dispersion lens has a dispersion range of 74mm, the rear working distance covers 113mm to 187mm, and the total length of the system is 152.122mm. The system has excellent single-point imaging effect, compact structure, easy assembly, high use value and wide application adaptability.

[0005] According to a first aspect of an embodiment of the present application, there is provided a white light confocal dispersion lens with an ultra-large range, comprising a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens coaxially arranged in sequence along the incident direction of light, wherein the first lens and the second lens form a first cemented lens, the third lens and the fourth lens form a second cemented lens, and the fifth lens and the sixth lens form a third cemented lens; The distance between the first cemented lens and the second cemented lens is 0 mm, and the distance between the second cemented lens and the third cemented lens is 3 mm to 5 mm; the distance between the object plane and the incident surface of the first lens is 105 mm to 115 mm, and the distance between the incident surface of the first lens and the exit surface of the sixth lens is 40 mm to 50 mm; The glass material of the first lens: 1.6 < n < 1.8, 50 < Vd < 60; the glass material of the second lens: 1.7 < n < 1.9, 20 < Vd < 30; the glass material of the third lens: 1.7 < n < 1.9, 20 < Vd < 30; the glass material of the fourth lens: 1.7 < n < 1.9, 45 < Vd < 55; the glass material of the fifth lens: 1.6 < n < 1.8, 50 < Vd < 60; the glass material of the sixth lens: 1.7 < n < 1.9, 20 < Vd < 30; where n is the refractive index and Vd is the Abbe number. Light enters from the first lens and finally exits through the sixth lens. In this process, the divergent light is preliminarily collimated by the first cemented lens, and preliminary dispersion processing is carried out at the same time. Then, the second cemented lens further focuses the light beam and completes the secondary dispersion. Finally, the light beam passes through the third cemented lens. Among them, the fifth lens is mainly used to correct the aberration of the system, and the sixth lens performs the third dispersion processing.

[0006] Preferably, the distance between the first cemented lens and the second cemented lens is 0 mm, and the distance between the second cemented lens and the third cemented lens is 4.122 mm; the distance between the object plane and the incident surface of the first lens is 110 mm, and the distance between the incident surface of the first lens and the exit surface of the sixth lens is 42.122 mm.

[0007] Optionally, the light beam emitted by the light source enters from the first lens and exits from the sixth lens, where: the first lens is a negative focal length lens, the incident surface is concave, -75 mm < r < -65 mm, the exit surface is concave, 120 mm < r < 130 mm; the second lens is a positive focal length lens, the incident surface is convex, 120 mm < r < 130 mm, the exit surface is convex, -60 mm < r < -50 mm; the third lens is a positive focal length lens, the incident surface is convex, 50 mm < r < 60 mm, the exit surface is convex, -60 mm < r < -50 mm; the fourth lens is a negative focal length lens, the incident surface is concave, -60 mm < r < -50 mm, the exit surface is concave, 230 mm < r < 240 mm; the fifth lens is a negative focal length lens, the incident surface is concave, -70 mm < r < -60 mm, the exit surface is concave, 20 mm < r < 30 mm; the sixth lens is a positive focal length lens, the incident surface is convex, 20 mm < r < 30 mm, the exit surface is convex, -870 mm < r < -860 mm; where r is the radius of curvature.

[0008] Optionally, the radius of curvature of the incident surface of the first lens is -70.3mm, and the radius of curvature of the exit surface is 123.2mm; the radius of curvature of the incident surface of the second lens is 123.2mm, and the radius of curvature of the exit surface is -54.3mm; the radius of curvature of the incident surface of the third lens is 57.7mm, and the radius of curvature of the exit surface is -55.7mm; the radius of curvature of the incident surface of the fourth lens is -55.7mm, and the radius of curvature of the exit surface is 238.3mm; the radius of curvature of the incident surface of the fifth lens is -62.1mm, and the radius of curvature of the exit surface is 24.1mm; the radius of curvature of the incident surface of the sixth lens is 24.1mm, and the radius of curvature of the exit surface is -866.5mm.

[0009] Optionally, the first lens and the fifth lens are made of the same glass material, and the second lens and the third lens are made of the same glass material.

[0010] Optionally, the distance from the object plane to the exit surface of the sixth lens (ie, the total length of the system) is 152.122 mm; and the maximum clear aperture of the six lenses constituting the dispersion lens is 17 mm.

[0011] According to a second aspect of an embodiment of the present application, a white light confocal measurement system is provided, comprising a white laser module, a spectrometer, a one-to-two optical fiber, and the ultra-large-range white light confocal dispersive lens described in the first aspect, wherein the white laser module, the white light confocal dispersive lens, and the spectrometer are connected via a one-to-two optical fiber.

[0012] The technical solution provided by the embodiments of the present application may have the following beneficial effects: It can be seen from the above embodiments that the light is incident from the first lens and finally emerges through the sixth lens. In this process, the divergent light is initially collimated by the first cemented lens composed of the first lens and the second lens, and the initial dispersion treatment is performed at the same time. Then, the second cemented lens composed of the third lens and the fourth lens further focuses the light beam and completes the secondary dispersion. Finally, the light beam passes through the third cemented lens composed of the fifth lens and the sixth lens, wherein the fifth lens is mainly used to correct the aberration of the system, and the sixth lens performs the third dispersion treatment. In order to achieve a wide range of dispersion, multiple lenses with high refractive index and low Abbe number are used in the design. The white light confocal dispersion lens has a dispersion range of 74mm, a rear working distance of 113mm to 187mm, a total system length of 152.122mm, an object numerical aperture (NA) of 0.13, and an image numerical aperture (NA') of 0.073. The system not only performs well in single-point imaging effect, but also has a compact structure and simple assembly, and has high practicality and broad application prospects.

[0013] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0015] Figure 1 1 is an optical structure diagram of a white light confocal dispersion lens provided in one embodiment of the present invention.

[0016] Figure 2 4 is a graph showing the relationship between the focus position and wavelength of a white light confocal dispersion lens provided in one embodiment of the present invention.

[0017] Figure 3 4 is a point diagram of a white light confocal dispersion lens provided by an embodiment of the present invention at a wavelength of 470 nm.

[0018] Figure 4 1 is a point diagram of a white light confocal dispersion lens provided by an embodiment of the present invention at a wavelength of 585 nm.

[0019] Figure 5 1 is a point diagram of a white light confocal dispersion lens provided by an embodiment of the present invention at a wavelength of 700 nm.

[0020] Figure 6 This is a light trace diagram of a white light confocal dispersion lens provided by an embodiment of the present invention at a wavelength of 470 nm.

[0021] Figure 7 This is a light trace diagram of a white light confocal dispersion lens provided by an embodiment of the present invention at a wavelength of 585 nm.

[0022] Figure 8 This is a light trace diagram of a white light confocal dispersion lens at a wavelength of 700 nm provided by an embodiment of the present invention.

[0023] Fig. 9 The figure is a schematic diagram of the structure of a white light confocal measurement system provided by an embodiment of the present invention.

[0024] In the figure: L1, first lens; L2, second lens; L3, third lens; L4, fourth lens; L5, fifth lens; L6, sixth lens; 21. White laser module; 22. Spectrometer; 23. One-to-two optical fiber; 24. White light confocal dispersion lens. DETAILED DESCRIPTION

[0025] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The implementations described in the following exemplary embodiments do not represent all implementations consistent with the present application. Instead, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the appended claims.

[0026] The terms used in this application are for the purpose of describing specific embodiments only and are not intended to limit this application. The singular forms of "a", "said" and "the" used in this application and the appended claims are also intended to include plural forms unless the context clearly indicates other meanings. It should also be understood that the term "and / or" used herein refers to and includes any or all possible combinations of one or more associated listed items.

[0027] It should be understood that although the terms first, second, third, etc. may be used in the present application to describe various information, these information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of the present application, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Depending on the context, the word "if" as used herein may be interpreted as "at the time of" or "when" or "in response to determining".

[0028] Reference Figure 1 As shown, an embodiment of the present invention provides a white light confocal dispersion lens with an ultra-wide range, comprising a first lens L1, a second lens L2, a third lens L3, a fourth lens L4, a fifth lens L5 and a sixth lens L6 which are coaxially arranged in sequence along the light incidence, wherein the first lens L1 and the second lens L2 form a first cemented lens, the third lens L3 and the fourth lens L4 form a second cemented lens, and the fifth lens L5 and the sixth lens L6 form a third cemented lens; light is incident from the first lens and finally emerges through the sixth lens. In this process, the divergent light is initially collimated by the first cemented lens and is initially dispersed at the same time, then the light beam is further focused by the second cemented lens and secondary dispersion is completed, and finally the light beam passes through the third cemented lens, wherein the fifth lens is mainly used to correct the aberration of the system, and the sixth lens is subjected to tertiary dispersion processing.

[0029] In one embodiment, the distance between the first cemented lens and the second cemented lens is 0 mm, and the distance between the second cemented lens and the third cemented lens is 3 mm; the distance from the object plane to the incident surface of the first lens L1 is 105 mm, and the distance from the incident surface of the first lens L1 to the exit surface of the sixth lens L6 is 40 mm.

[0030] In another embodiment, the distance between the first cemented lens and the second cemented lens is 0 mm, and the distance between the second cemented lens and the third cemented lens is 5 mm; the distance between the object surface and the incident surface of the first lens L1 is 115 mm, and the distance between the incident surface of the first lens L1 and the exit surface of the sixth lens L6 is 50 mm.

[0031] In a preferred embodiment, the distance between the first cemented lens and the second cemented lens is 0 mm, and the distance between the second cemented lens and the third cemented lens is 4.122 mm; the distance between the object surface and the incident surface of the first lens L1 is 110 mm, and the distance between the incident surface of the first lens L1 and the exit surface of the sixth lens L6 is 42.122 mm.

[0032] In one embodiment, the light beam emitted by the light source is incident on the first lens L1 and exits from the sixth lens L6, where: the first lens L1 is a negative focal length lens, the incident surface is concave, -75 mm < r < -65 mm, the exit surface is concave, 120 mm < r < 130 mm; the second lens L2 is a positive focal length lens, the incident surface is convex, 120 mm < r < 130 mm, the exit surface is convex, -60 mm < r < -50 mm; the third lens L3 is a positive focal length lens, the incident surface is convex, 50 mm < r < 60 mm, the exit surface is convex, -60 mm < r < -50 mm; the fourth lens L4 is a negative focal length lens, the incident surface is concave, -60 mm < r < -50 mm, the exit surface is concave, 230 mm < r < 240 mm; the fifth lens L5 is a negative focal length lens, the incident surface is concave, -70 mm < r < -60 mm, the exit surface is concave, 20 mm < r < 30 mm; the sixth lens L6 is a positive focal length lens, the incident surface is convex, 20 mm < r < 30 mm, the exit surface is convex, -870 mm < r < -860 mm; where r is the radius of curvature. By reasonably configuring the positive focal length lens and the negative focal length lens and designing the radius of curvature of each lens, the collimation, focusing and dispersion processing of the light beam are optimized, and the synergistic effect between the lenses effectively reduces the aberration, ensuring high-precision measurement within an ultra-large range.

[0033] In one embodiment, the radius of curvature of the incident surface of the first lens L1 is -75 mm, and the radius of curvature of the exit surface is 120 mm; the radius of curvature of the incident surface of the second lens L2 is 120 mm, and the radius of curvature of the exit surface is -60 mm; the radius of curvature of the incident surface of the third lens L3 is 50 mm, and the radius of curvature of the exit surface is -60 mm; the radius of curvature of the incident surface of the fourth lens L4 is -60 mm, and the radius of curvature of the exit surface is 230 mm; the radius of curvature of the incident surface of the fifth lens L5 is -70 mm, and the radius of curvature of the exit surface is 20 mm; the radius of curvature of the incident surface of the sixth lens L6 is 20 mm, and the radius of curvature of the exit surface is -870 mm.

[0034] In another embodiment, the radius of curvature of the incident surface of the first lens L1 is -65 mm, and the radius of curvature of the exit surface is 130 mm; the radius of curvature of the incident surface of the second lens L2 is 130 mm, and the radius of curvature of the exit surface is -50 mm; the radius of curvature of the incident surface of the third lens L3 is 60 mm, and the radius of curvature of the exit surface is -50 mm; the radius of curvature of the incident surface of the fourth lens L4 is -50 mm, and the radius of curvature of the exit surface is 240 mm; the radius of curvature of the incident surface of the fifth lens L5 is -60 mm, and the radius of curvature of the exit surface is 30 mm; the radius of curvature of the incident surface of the sixth lens L6 is 30 mm, and the radius of curvature of the exit surface is -860 mm.

[0035] In a preferred embodiment, the radius of curvature of the incident surface of the first lens L1 is -70.3 mm, and the radius of curvature of the exit surface is 123.2 mm; the radius of curvature of the incident surface of the second lens L2 is 123.2 mm, and the radius of curvature of the exit surface is -54.3 mm; the radius of curvature of the incident surface of the third lens L3 is 57.7 mm, and the radius of curvature of the exit surface is -55.7 mm; the radius of curvature of the incident surface of the fourth lens L4 is -55.7 mm, and the radius of curvature of the exit surface is 238.3 mm; the radius of curvature of the incident surface of the fifth lens L5 is -62.1 mm, and the radius of curvature of the exit surface is 24.1 mm; the radius of curvature of the incident surface of the sixth lens L6 is 24.1 mm, and the radius of curvature of the exit surface is -866.5 mm.

[0036] In one embodiment, the glass material of the first lens L1: 1.6 < n < 1.8, 50 < Vd < 60; the glass material of the second lens L2: 1.7 < n < 1.9, 20 < Vd < 30; the glass material of the third lens L3: 1.7 < n < 1.9, 20 < Vd < 30; the glass material of the fourth lens L4: 1.7 < n < 1.9, 45 < Vd < 55; the glass material of the fifth lens L5: 1.6 < n < 1.8, 50 < Vd < 60; the glass material of the sixth lens L6: 1.7 < n < 1.9, 20 < Vd < 30; where n is the refractive index and Vd is the Abbe number. By reasonably selecting the glass materials of each lens, the system controls the refractive index (n) and the Abbe number (Vd), effectively reducing spherical aberration, coma and other aberrations in the system. It not only improves the dispersion performance of the optical system, but also enhances the imaging quality and measurement accuracy of the system, ensuring high-precision and stable measurement effects within a very large measurement range.

[0037] In one embodiment, the first lens L1 and the fifth lens L5 use the same glass material, and the second lens L2 and the third lens L3 use the same glass material. Optimizing the lens structure and the selection of glass materials not only simplifies the manufacturing process and reduces the production cost, but also effectively reduces the influence of chromatic aberration and temperature fluctuations caused by material differences on the optical performance, thereby improving the stability and measurement accuracy of the system.

[0038] In one embodiment, the distance between the object surface and the exit surface of the sixth lens L6 (i.e., the total system length) is 152.122 mm; among the six lenses that make up the dispersion lens, the maximum clear aperture is 17 mm. On the premise of ensuring a large dispersion range, this dispersion lens effectively reduces the system volume, optimizes the design, and improves the compactness of the overall structure.

[0039] Table 1 Parameters of the lens group: surface Radius of curvature (unit / mm) Net diameter (unit / mm) The first lens L1 incident surface -70.3 14.232 The first lens L1 exit surface 123.2 17 The second lens L2 incident surface 123.2 17 The second lens L2 exit surface -54.3 17 The incident surface of the third lens L3 57.7 17 The third lens L3 exit surface -55.7 17 The incident surface of the fourth lens L4 -55.7 17 The fourth lens L4 exit surface 238.3 14.814 Fifth lens L5 incident surface -62.1 14.39 Fifth lens L5 exit surface 24.1 15 The sixth lens L6 exit surface 24.1 15 The sixth lens L6 exit surface -866.5 14.05 In one embodiment, Table 1 gives the parameters of the lens group of the white-light confocal dispersion lens. The light enters from the entrance surface of the first lens L1 and finally exits from the exit surface of the sixth lens L6. During this process, the divergent light is preliminarily collimated by the first cemented lens composed of the first lens L1 and the second lens L2, and preliminary dispersion processing is carried out at the same time. Then, the second cemented lens composed of the third lens L3 and the fourth lens L4 further focuses the light beam and completes the secondary dispersion. Finally, the light beam passes through the third cemented lens composed of the fifth lens L5 and the sixth lens L6. Among them, the fifth lens L5 is mainly used to correct the aberrations of the system, while the sixth lens L6 performs the third dispersion processing.

[0040] See Appendix Figure 2From the focus position and wavelength relationship diagram of the white light confocal dispersion lens provided in this embodiment, it can be seen that the dispersion lens achieves a dispersion range of 74mm in the wavelength range of 470nm~700nm, and the back working distance is 113mm~187mm.

[0041] See attached Figure 3 The spot diagram of the white light confocal dispersion lens provided in this embodiment at a wavelength of 470nm is shown in the attached figure. Figure 4 The spot diagram of the white light confocal dispersion lens provided in this embodiment at a wavelength of 585nm is shown in the attached figure. Figure 5 The spot diagram of the white light confocal dispersion lens provided in this embodiment at a wavelength of 700nm. The spot diagram shows that the spot size of each field of view is less than or equal to the Airy disk, indicating that the system is close to the diffraction limit. Figure 6 The light trace diagram of the white light confocal dispersion lens provided in this embodiment at a wavelength of 470nm is shown in the figure. Figure 7 The light trace diagram of the white light confocal dispersion lens provided in this embodiment at a wavelength of 585nm is shown in the figure below. Figure 8 The light trace diagram of the white light confocal dispersive lens provided in this embodiment at a wavelength of 700nm. In the lens design, the object height of the system is set to 50μm. From the light trace diagram, it can be seen that the image height of the system is also 50μm, and the entire dispersive lens has a one-fold magnification relationship from object to image.

[0042] It can be seen from the above embodiments that the present application provides a super-wide-range white light confocal dispersion lens, which is composed of six lenses. The dispersion lens has a dispersion range of 74mm, and the rear working distance covers 113mm to 187mm. The total length of the system is 152.122mm, which can meet the needs of high-precision measurement in a super-large measurement range. The system has excellent single-point imaging effect, compact structure, easy assembly, high use value and wide application adaptability.

[0043] refer to Fig. 9 The embodiment of the present invention also provides a white light confocal measurement system, including a white laser module 21, a spectrometer 22, a split-two optical fiber 23 and the above-mentioned ultra-large range white light confocal dispersive lens 24, wherein the white laser module 21, the white light confocal dispersive lens 24 and the spectrometer 22 are connected through a split-two optical fiber. The light emitted by the white laser module 21 is incident from the branch end ① of the split-two optical fiber 23, and is emitted from the common end ② to enter the white light confocal dispersive lens 24, and passes through the first lens L1 to the sixth lens L6 in sequence. After the dispersion effect, the dispersed light is irradiated on the target object, and the single-wavelength light focused on the target object is reflected and returned to the white light confocal dispersive lens 24, and then passes through the sixth lens L6 to the first lens L1 in sequence, and is emitted from the branch end ③ to enter the spectrometer 22.

[0044] Those skilled in the art will readily appreciate other embodiments of the present application after considering the description and practicing the contents disclosed herein. The present application is intended to cover any modification, use or adaptation of the present application, which follows the general principles of the present application and includes common knowledge or customary techniques in the art that are not disclosed in the present application. The description and examples are intended to be exemplary only, and the true scope and spirit of the present application are indicated by the claims.

[0045] It should be understood that the present application is not limited to the precise structures that have been described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present application is limited only by the appended claims.

Claims

1. A super-wide-range white light confocal dispersion lens, characterized in that: It includes a first lens, a second lens, a third lens, a fourth lens, a fifth lens and a sixth lens which are coaxially arranged in sequence along the incident light. Among them, the first lens and the second lens form a first cemented lens, the third lens and the fourth lens form a second cemented lens, and the fifth lens and the sixth lens form a third cemented lens; The distance between the first cemented lens and the second cemented lens is 0 mm, and the distance between the second cemented lens and the third cemented lens is 3 mm to 5 mm; the distance between the object plane and the incident surface of the first lens is 105 mm to 115 mm, and the distance between the incident surface of the first lens and the exit surface of the sixth lens is 40 mm to 50 mm; The glass material of the first lens: 1.6 < n < 1.8, 50 < Vd < 60; the glass material of the second lens: 1.7 < n < 1.9, 20 < Vd < 30; the glass material of the third lens: 1.7 < n < 1.9, 20 < Vd < 30; the glass material of the fourth lens: 1.7 < n < 1.9, 45 < Vd < 55; the glass material of the fifth lens: 1.6 < n < 1.8, 50 < Vd < 60; the glass material of the sixth lens: 1.7 < n < 1.9, 20 < Vd < 30; where n is the refractive index and Vd is the Abbe number; Light enters from the first lens and finally exits through the sixth lens. In this process, the divergent light is preliminarily collimated by the first cemented lens and undergoes preliminary dispersion processing at the same time. Then, the beam is further focused by the second cemented lens and the secondary dispersion is completed. Finally, the beam passes through the third cemented lens. Among them, the fifth lens is mainly used to correct the aberration of the system, and the sixth lens performs the third dispersion processing.

2. The ultra-wide-range white light confocal dispersion lens according to claim 1, characterized in that: The distance between the first cemented lens and the second cemented lens is 0 mm, and the distance between the second cemented lens and the third cemented lens is 4.122 mm; the distance between the object plane and the incident surface of the first lens is 110 mm, and the distance between the incident surface of the first lens and the exit surface of the sixth lens is 42.122 mm.

3. The ultra-wide-range white light confocal dispersion lens according to claim 1, characterized in that: The light beam emitted by the light source enters through the first lens and exits through the sixth lens, where: the first lens is a negative focal length lens, the incident surface is concave, -75 mm < r < -65 mm, the exit surface is concave, 120 mm < r < 130 mm; the second lens is a positive focal length lens, the incident surface is convex, 120 mm < r < 130 mm, the exit surface is convex, -60 mm < r < -50 mm; the third lens is a positive focal length lens, the incident surface is convex, 50 mm < r < 60 mm, the exit surface is convex, -60 mm < r < -50 mm; the fourth lens is a negative focal length lens, the incident surface is concave, -60 mm < r < -50 mm, the exit surface is concave, 230 mm < r < 240 mm; the fifth lens is a negative focal length lens, the incident surface is concave, -70 mm < r < -60 mm, the exit surface is concave, 20 mm < r < 30 mm; the sixth lens is a positive focal length lens, the incident surface is convex, 20 mm < r < 30 mm, the exit surface is convex, -870 mm < r < -860 mm; where r is the radius of curvature.

4. The ultra-wide-range white light confocal dispersion lens according to claim 1, characterized in that: The radius of curvature of the incident surface of the first lens is -70.3 mm, and the radius of curvature of the exit surface is 123.2 mm; the radius of curvature of the incident surface of the second lens is 123.2 mm, and the radius of curvature of the exit surface is -54.3 mm; the radius of curvature of the incident surface of the third lens is 57.7 mm, and the radius of curvature of the exit surface is -55.7 mm; the radius of curvature of the incident surface of the fourth lens is -55.7 mm, and the radius of curvature of the exit surface is 238.3 mm; the radius of curvature of the incident surface of the fifth lens is -62.1 mm, and the radius of curvature of the exit surface is 24.1 mm; the radius of curvature of the incident surface of the sixth lens is 24.1 mm, and the radius of curvature of the exit surface is -866.5 mm.

5. The ultra-wide-range white light confocal dispersion lens according to claim 1, characterized in that: The first lens and the fifth lens are made of the same type of glass material, and the second lens and the third lens are made of the same type of glass material.

6. The ultra-wide-range white light confocal dispersion lens according to claim 1, characterized in that: The distance between the object surface and the exit surface of the sixth lens is 152.122 mm; Among the six lenses that make up the dispersion lens, the maximum clear aperture is 17 mm.

7. A white light confocal measurement system, characterized in that: It includes a white laser module, a spectrometer, a one-to-two optical fiber, and the ultra-large-range white-light confocal dispersion lens according to any one of claims 1-6. The white laser module, the white-light confocal dispersion lens, and the spectrometer are connected by a one-to-two optical fiber.

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